# File lib/sequel/database/schema_methods.rb 912 def primary_key_constraint_sql_fragment(_) 913 'PRIMARY KEY' 914 end
class Sequel::Database
A Database
object represents a virtual connection to a database. The Database
class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.
Constants
- OPTS
1 - Methods that execute queries and/or return results
↑ topConstants
- COLUMN_SCHEMA_DATETIME_TYPES
- COLUMN_SCHEMA_STRING_TYPES
- INTEGER1_MIN_MAX
- INTEGER2_MIN_MAX
- INTEGER3_MIN_MAX
- INTEGER4_MIN_MAX
- INTEGER8_MIN_MAX
- UNSIGNED_INTEGER1_MIN_MAX
- UNSIGNED_INTEGER2_MIN_MAX
- UNSIGNED_INTEGER3_MIN_MAX
- UNSIGNED_INTEGER4_MIN_MAX
- UNSIGNED_INTEGER8_MIN_MAX
Attributes
Whether the schema should be cached for this database. True by default for performance, can be set to false to always issue a database query to get the schema.
The prepared statement object hash for this database, keyed by name symbol
Public Instance Methods
Runs the supplied SQL statement string on the database server. Returns self so it can be safely chained:
DB << "UPDATE albums SET artist_id = NULL" << "DROP TABLE artists"
# File lib/sequel/database/query.rb 25 def <<(sql) 26 run(sql) 27 self 28 end
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].where(id: 1).prepare(:first, :sa) DB.call(:sa) # SELECT * FROM items WHERE id = 1
# File lib/sequel/database/query.rb 35 def call(ps_name, hash=OPTS, &block) 36 prepared_statement(ps_name).call(hash, &block) 37 end
Method that should be used when submitting any DDL (Data Definition Language) SQL, such as create_table
. By default, calls execute_dui
. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 42 def execute_ddl(sql, opts=OPTS, &block) 43 execute_dui(sql, opts, &block) 44 end
Method that should be used when issuing a DELETE or UPDATE statement. By default, calls execute. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 49 def execute_dui(sql, opts=OPTS, &block) 50 execute(sql, opts, &block) 51 end
Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 56 def execute_insert(sql, opts=OPTS, &block) 57 execute_dui(sql, opts, &block) 58 end
Returns a single value from the database, see Dataset#get.
DB.get(1) # SELECT 1 # => 1 DB.get{server_version.function} # SELECT server_version()
# File lib/sequel/database/query.rb 65 def get(*args, &block) 66 @default_dataset.get(*args, &block) 67 end
Runs the supplied SQL statement string on the database server. Returns nil. Options:
- :server
-
The server to run the SQL on.
DB.run("SET some_server_variable = 42")
# File lib/sequel/database/query.rb 74 def run(sql, opts=OPTS) 75 sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString) 76 execute_ddl(sql, opts) 77 nil 78 end
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:
- :reload
-
Ignore any cached results, and get fresh information from the database.
- :schema
-
An explicit schema to use. It may also be implicitly provided via the table name.
If schema parsing is supported by the database, the column information hash should contain at least the following entries:
- :allow_null
-
Whether NULL is an allowed value for the column.
- :db_type
-
The database type for the column, as a database specific string.
- :default
-
The database default for the column, as a database specific string, or nil if there is no default value.
- :primary_key
-
Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key.
- :ruby_default
-
The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value.
- :type
-
A symbol specifying the type, such as :integer or :string.
Example:
DB.schema(:artists) # [[:id, # {:type=>:integer, # :primary_key=>true, # :default=>"nextval('artist_id_seq'::regclass)", # :ruby_default=>nil, # :db_type=>"integer", # :allow_null=>false}], # [:name, # {:type=>:string, # :primary_key=>false, # :default=>nil, # :ruby_default=>nil, # :db_type=>"text", # :allow_null=>false}]]
# File lib/sequel/database/query.rb 121 def schema(table, opts=OPTS) 122 raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing? 123 124 opts = opts.dup 125 tab = if table.is_a?(Dataset) 126 o = table.opts 127 from = o[:from] 128 raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) 129 table.first_source_table 130 else 131 table 132 end 133 134 qualifiers = split_qualifiers(tab) 135 table_name = qualifiers.pop 136 sch = qualifiers.pop 137 information_schema_schema = case qualifiers.length 138 when 1 139 Sequel.identifier(*qualifiers) 140 when 2 141 Sequel.qualify(*qualifiers) 142 end 143 144 if table.is_a?(Dataset) 145 quoted_name = table.literal(tab) 146 opts[:dataset] = table 147 else 148 quoted_name = schema_utility_dataset.literal(table) 149 end 150 151 opts[:schema] = sch if sch && !opts.include?(:schema) 152 opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema) 153 154 Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] 155 if v = Sequel.synchronize{@schemas[quoted_name]} 156 return v 157 end 158 159 cols = schema_parse_table(table_name, opts) 160 raise(Error, "schema parsing returned no columns, table #{table_name.inspect} probably doesn't exist") if cols.nil? || cols.empty? 161 162 primary_keys = 0 163 auto_increment_set = false 164 cols.each do |_,c| 165 auto_increment_set = true if c.has_key?(:auto_increment) 166 primary_keys += 1 if c[:primary_key] 167 end 168 169 cols.each do |_,c| 170 c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type]) unless c.has_key?(:ruby_default) 171 if c[:primary_key] && !auto_increment_set 172 # If adapter didn't set it, assume that integer primary keys are auto incrementing 173 c[:auto_increment] = primary_keys == 1 && !!(c[:db_type] =~ /int/io) 174 end 175 if !c[:max_length] && c[:type] == :string && (max_length = column_schema_max_length(c[:db_type])) 176 c[:max_length] = max_length 177 end 178 if !c[:max_value] && !c[:min_value] && c[:type] == :integer && (min_max = column_schema_integer_min_max_values(c[:db_type])) 179 c[:min_value], c[:max_value] = min_max 180 end 181 end 182 schema_post_process(cols) 183 184 Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema 185 cols 186 end
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false # SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don't have permission to SELECT from the table.
# File lib/sequel/database/query.rb 196 def table_exists?(name) 197 sch, table_name = schema_and_table(name) 198 name = SQL::QualifiedIdentifier.new(sch, table_name) if sch 199 ds = from(name) 200 transaction(:savepoint=>:only){_table_exists?(ds)} 201 true 202 rescue DatabaseError 203 false 204 end
Private Instance Methods
Uncached version of metadata_dataset
, designed for overriding.
# File lib/sequel/database/query.rb 328 def _metadata_dataset 329 dataset 330 end
Should raise an error if the table doesn't not exist, and not raise an error if the table does exist.
# File lib/sequel/database/query.rb 210 def _table_exists?(ds) 211 ds.get(SQL::AliasedExpression.new(Sequel::NULL, :nil)) 212 end
Whether the type should be treated as a string type when parsing the column schema default value.
# File lib/sequel/database/query.rb 216 def column_schema_default_string_type?(type) 217 COLUMN_SCHEMA_STRING_TYPES.include?(type) 218 end
Transform the given normalized default string into a ruby object for the given type.
# File lib/sequel/database/query.rb 222 def column_schema_default_to_ruby_value(default, type) 223 case type 224 when :boolean 225 case default 226 when /[f0]/i 227 false 228 when /[t1]/i 229 true 230 end 231 when :string, :enum, :set, :interval 232 default 233 when :blob 234 Sequel::SQL::Blob.new(default) 235 when :integer 236 Integer(default) 237 when :float 238 Float(default) 239 when :date 240 Sequel.string_to_date(default) 241 when :datetime 242 Sequel.string_to_datetime(default) 243 when :time 244 Sequel.string_to_time(default) 245 when :decimal 246 BigDecimal(default) 247 end 248 end
Look at the db_type and guess the minimum and maximum integer values for the column.
# File lib/sequel/database/query.rb 291 def column_schema_integer_min_max_values(db_type) 292 unsigned = /unsigned/i =~ db_type 293 case db_type 294 when /big|int8/i 295 unsigned ? UNSIGNED_INTEGER8_MIN_MAX : INTEGER8_MIN_MAX 296 when /medium/i 297 unsigned ? UNSIGNED_INTEGER3_MIN_MAX : INTEGER3_MIN_MAX 298 when /small|int2/i 299 unsigned ? UNSIGNED_INTEGER2_MIN_MAX : INTEGER2_MIN_MAX 300 when /tiny/i 301 (unsigned || column_schema_tinyint_type_is_unsigned?) ? UNSIGNED_INTEGER1_MIN_MAX : INTEGER1_MIN_MAX 302 else 303 unsigned ? UNSIGNED_INTEGER4_MIN_MAX : INTEGER4_MIN_MAX 304 end 305 end
Look at the db_type and guess the maximum length of the column. This assumes types such as varchar(255).
# File lib/sequel/database/query.rb 314 def column_schema_max_length(db_type) 315 if db_type =~ /\((\d+)\)/ 316 $1.to_i 317 end 318 end
Normalize the default value string for the given type and return the normalized value.
# File lib/sequel/database/query.rb 252 def column_schema_normalize_default(default, type) 253 if column_schema_default_string_type?(type) 254 return unless m = /\A'(.*)'\z/.match(default) 255 m[1].gsub("''", "'") 256 else 257 default 258 end 259 end
Whether the tinyint type (if supported by the database) is unsigned by default.
# File lib/sequel/database/query.rb 308 def column_schema_tinyint_type_is_unsigned? 309 false 310 end
Convert the given default, which should be a database specific string, into a ruby object.
# File lib/sequel/database/query.rb 263 def column_schema_to_ruby_default(default, type) 264 return default unless default.is_a?(String) 265 if COLUMN_SCHEMA_DATETIME_TYPES.include?(type) 266 if /now|today|CURRENT|getdate|\ADate\(\)\z/i.match(default) 267 if type == :date 268 return Sequel::CURRENT_DATE 269 else 270 return Sequel::CURRENT_TIMESTAMP 271 end 272 end 273 end 274 default = column_schema_normalize_default(default, type) 275 column_schema_default_to_ruby_value(default, type) rescue nil 276 end
Return a Method object for the dataset's output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 323 def input_identifier_meth(ds=nil) 324 (ds || dataset).method(:input_identifier) 325 end
Return a dataset that uses the default identifier input and output methods for this database. Used when parsing metadata so that column symbols are returned as expected.
# File lib/sequel/database/query.rb 335 def metadata_dataset 336 @metadata_dataset ||= _metadata_dataset 337 end
Return a Method object for the dataset's output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 342 def output_identifier_meth(ds=nil) 343 (ds || dataset).method(:output_identifier) 344 end
Remove the cached schema for the given schema name
# File lib/sequel/database/query.rb 347 def remove_cached_schema(table) 348 cache = @default_dataset.send(:cache) 349 Sequel.synchronize{cache.clear} 350 k = quote_schema_table(table) 351 Sequel.synchronize{@schemas.delete(k)} 352 end
Match the database's column type to a ruby type via a regular expression, and return the ruby type as a symbol such as :integer or :string.
# File lib/sequel/database/query.rb 357 def schema_column_type(db_type) 358 case db_type 359 when /\A(character( varying)?|n?(var)?char|n?text|string|clob)/io 360 :string 361 when /\A(int(eger)?|(big|small|tiny)int)/io 362 :integer 363 when /\Adate\z/io 364 :date 365 when /\A((small)?datetime|timestamp(\(\d\))?( with(out)? time zone)?)\z/io 366 :datetime 367 when /\Atime( with(out)? time zone)?\z/io 368 :time 369 when /\A(bool(ean)?)\z/io 370 :boolean 371 when /\A(real|float( unsigned)?|double( precision)?|double\(\d+,\d+\)( unsigned)?)\z/io 372 :float 373 when /\A(?:(?:(?:num(?:ber|eric)?|decimal)(?:\(\d+,\s*(\d+|false|true)\))?))\z/io 374 $1 && ['0', 'false'].include?($1) ? :integer : :decimal 375 when /bytea|blob|image|(var)?binary/io 376 :blob 377 when /\Aenum/io 378 :enum 379 end 380 end
Post process the schema values.
# File lib/sequel/database/query.rb 383 def schema_post_process(cols) 384 # :nocov: 385 if RUBY_VERSION >= '2.5' 386 # :nocov: 387 cols.each do |_, h| 388 db_type = h[:db_type] 389 if db_type.is_a?(String) 390 h[:db_type] = -db_type 391 end 392 end 393 end 394 395 cols.each do |_,c| 396 c.each_value do |val| 397 val.freeze if val.is_a?(String) 398 end 399 end 400 end
2 - Methods that modify the database schema
↑ topConstants
- COLUMN_DEFINITION_ORDER
The order of column modifiers to use when defining a column.
- COMBINABLE_ALTER_TABLE_OPS
The alter table operations that are combinable.
Public Instance Methods
Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:
DB.add_column :items, :name, String, unique: true, null: false DB.add_column :items, :category, String, default: 'ruby'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 25 def add_column(table, *args) 26 alter_table(table) {add_column(*args)} 27 end
Adds an index to a table for the given columns:
DB.add_index :posts, :title DB.add_index :posts, [:author, :title], unique: true
Options:
- :ignore_errors
-
Ignore any DatabaseErrors that are raised
- :name
-
Name to use for index instead of default
See alter_table
.
# File lib/sequel/database/schema_methods.rb 40 def add_index(table, columns, options=OPTS) 41 e = options[:ignore_errors] 42 begin 43 alter_table(table){add_index(columns, options)} 44 rescue DatabaseError 45 raise unless e 46 end 47 nil 48 end
Alters the given table with the specified block. Example:
DB.alter_table :items do add_column :category, String, default: 'ruby' drop_column :category rename_column :cntr, :counter set_column_type :value, Float set_column_default :value, 4.2 add_index [:group, :category] drop_index [:group, :category] end
Note that add_column
accepts all the options available for column definitions using create_table
, and add_index
accepts all the options available for index definition.
See Schema::AlterTableGenerator
and the Migrations guide.
# File lib/sequel/database/schema_methods.rb 67 def alter_table(name, &block) 68 generator = alter_table_generator(&block) 69 remove_cached_schema(name) 70 apply_alter_table_generator(name, generator) 71 nil 72 end
Return a new Schema::AlterTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 76 def alter_table_generator(&block) 77 alter_table_generator_class.new(self, &block) 78 end
Create a join table using a hash of foreign keys to referenced table names. Example:
create_join_table(cat_id: :cats, dog_id: :dogs) # CREATE TABLE cats_dogs ( # cat_id integer NOT NULL REFERENCES cats, # dog_id integer NOT NULL REFERENCES dogs, # PRIMARY KEY (cat_id, dog_id) # ) # CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)
The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.
The default table name this will create is the sorted version of the two hash values, joined by an underscore. So the following two method calls create the same table:
create_join_table(cat_id: :cats, dog_id: :dogs) # cats_dogs create_join_table(dog_id: :dogs, cat_id: :cats) # cats_dogs
You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:
create_join_table(cat_id: {table: :cats, type: :Bignum}, dog_id: :dogs)
You can provide a second argument which is a table options hash:
create_join_table({cat_id: :cats, dog_id: :dogs}, temp: true)
Some table options are handled specially:
- :index_options
-
The options to pass to the index
- :name
-
The name of the table to create
- :no_index
-
Set to true not to create the second index.
- :no_primary_key
-
Set to true to not create the primary key.
# File lib/sequel/database/schema_methods.rb 119 def create_join_table(hash, options=OPTS) 120 keys = hash.keys.sort 121 create_table(join_table_name(hash, options), options) do 122 keys.each do |key| 123 v = hash[key] 124 unless v.is_a?(Hash) 125 v = {:table=>v} 126 end 127 v[:null] = false unless v.has_key?(:null) 128 foreign_key(key, v) 129 end 130 primary_key(keys) unless options[:no_primary_key] 131 index(keys.reverse, options[:index_options] || OPTS) unless options[:no_index] 132 end 133 nil 134 end
Forcibly create a join table, attempting to drop it if it already exists, then creating it.
# File lib/sequel/database/schema_methods.rb 137 def create_join_table!(hash, options=OPTS) 138 drop_table?(join_table_name(hash, options)) 139 create_join_table(hash, options) 140 end
Creates the join table unless it already exists.
# File lib/sequel/database/schema_methods.rb 143 def create_join_table?(hash, options=OPTS) 144 if supports_create_table_if_not_exists? && options[:no_index] 145 create_join_table(hash, options.merge(:if_not_exists=>true)) 146 elsif !table_exists?(join_table_name(hash, options)) 147 create_join_table(hash, options) 148 end 149 end
Creates a view, replacing a view with the same name if one already exists.
DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100") DB.create_or_replace_view(:some_items, DB[:items].where(category: 'ruby'))
For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.
# File lib/sequel/database/schema_methods.rb 248 def create_or_replace_view(name, source, options = OPTS) 249 if supports_create_or_replace_view? 250 options = options.merge(:replace=>true) 251 else 252 swallow_database_error{drop_view(name)} 253 end 254 255 create_view(name, source, options) 256 nil 257 end
Creates a table with the columns given in the provided block:
DB.create_table :posts do primary_key :id column :title, String String :content index :title end
General options:
- :as
-
Create the table using the value, which should be either a dataset or a literal SQL string. If this option is used, a block should not be given to the method.
- :ignore_index_errors
-
Ignore any errors when creating indexes.
- :temp
-
Create the table as a temporary table.
MySQL specific options:
- :charset
-
The character set to use for the table.
- :collate
-
The collation to use for the table.
- :engine
-
The table engine to use for the table.
PostgreSQL specific options:
- :on_commit
-
Either :preserve_rows (default), :drop or :delete_rows. Should only be specified when creating a temporary table.
- :foreign
-
Create a foreign table. The value should be the name of the foreign server that was specified in CREATE SERVER.
- :inherits
-
Inherit from a different table. An array can be specified to inherit from multiple tables.
- :unlogged
-
Create the table as an unlogged table.
- :options
-
The OPTIONS clause to use for foreign tables. Should be a hash where keys are option names and values are option values. Note that option names are unquoted, so you should not use untrusted keys.
- :tablespace
-
The tablespace to use for the table.
SQLite specific options:
- :strict
-
Create a STRICT table, which checks that the values for the columns are the correct type (similar to all other SQL databases). Note that when using this option, all column types used should be one of the following:
int
,integer
,real
,text
,blob
, andany
. Theany
type is treated like a SQLite column in a non-strict table, allowing any type of data to be stored. This option is supported on SQLite 3.37.0+.
See Schema::CreateTableGenerator
and the “Schema Modification” guide.
# File lib/sequel/database/schema_methods.rb 196 def create_table(name, options=OPTS, &block) 197 remove_cached_schema(name) 198 if sql = options[:as] 199 raise(Error, "can't provide both :as option and block to create_table") if block 200 create_table_as(name, sql, options) 201 else 202 generator = options[:generator] || create_table_generator(&block) 203 create_table_from_generator(name, generator, options) 204 create_table_indexes_from_generator(name, generator, options) 205 end 206 nil 207 end
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- drop table if already exists # CREATE TABLE a (a integer)
# File lib/sequel/database/schema_methods.rb 215 def create_table!(name, options=OPTS, &block) 216 drop_table?(name) 217 create_table(name, options, &block) 218 end
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # CREATE TABLE a (a integer) -- if it doesn't already exist
# File lib/sequel/database/schema_methods.rb 225 def create_table?(name, options=OPTS, &block) 226 options = options.dup 227 generator = options[:generator] ||= create_table_generator(&block) 228 if generator.indexes.empty? && supports_create_table_if_not_exists? 229 create_table(name, options.merge!(:if_not_exists=>true)) 230 elsif !table_exists?(name) 231 create_table(name, options) 232 end 233 end
Return a new Schema::CreateTableGenerator instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 237 def create_table_generator(&block) 238 create_table_generator_class.new(self, &block) 239 end
Creates a view based on a dataset or an SQL string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100") # CREATE VIEW cheap_items AS # SELECT * FROM items WHERE price < 100 DB.create_view(:ruby_items, DB[:items].where(category: 'ruby')) # CREATE VIEW ruby_items AS # SELECT * FROM items WHERE (category = 'ruby') DB.create_view(:checked_items, DB[:items].where(:foo), check: true) # CREATE VIEW checked_items AS # SELECT * FROM items WHERE foo # WITH CHECK OPTION DB.create_view(:bar_items, DB[:items].select(:foo), columns: [:bar]) # CREATE VIEW bar_items (bar) AS # SELECT foo FROM items
Options:
- :columns
-
The column names to use for the view. If not given, automatically determined based on the input dataset.
- :check
-
Adds a WITH CHECK OPTION clause, so that attempting to modify rows in the underlying table that would not be returned by the view is not allowed. This can be set to :local to use WITH LOCAL CHECK OPTION.
PostgreSQL/SQLite specific option:
- :temp
-
Create a temporary view, automatically dropped on disconnect.
PostgreSQL specific options:
- :materialized
-
Creates a materialized view, similar to a regular view, but backed by a physical table.
- :recursive
-
Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn't in a subquery, if you are providing a Dataset as the source argument, if should probably call the union method with the all: true and from_self: false options.
- :security_invoker
-
Set the security_invoker property on the view, making the access to the view use the current user's permissions, instead of the view owner's permissions.
- :tablespace
-
The tablespace to use for materialized views.
# File lib/sequel/database/schema_methods.rb 302 def create_view(name, source, options = OPTS) 303 execute_ddl(create_view_sql(name, source, options)) 304 remove_cached_schema(name) 305 nil 306 end
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table
.
# File lib/sequel/database/schema_methods.rb 313 def drop_column(table, *args) 314 alter_table(table) {drop_column(*args)} 315 end
Removes an index for the given table and column(s):
DB.drop_index :posts, :title DB.drop_index :posts, [:author, :title]
See alter_table
.
# File lib/sequel/database/schema_methods.rb 323 def drop_index(table, columns, options=OPTS) 324 alter_table(table){drop_index(columns, options)} 325 end
Drop the join table that would have been created with the same arguments to create_join_table
:
drop_join_table(cat_id: :cats, dog_id: :dogs) # DROP TABLE cats_dogs
# File lib/sequel/database/schema_methods.rb 332 def drop_join_table(hash, options=OPTS) 333 drop_table(join_table_name(hash, options), options) 334 end
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) # DROP TABLE posts DB.drop_table(:posts, :comments) DB.drop_table(:posts, :comments, cascade: true)
# File lib/sequel/database/schema_methods.rb 341 def drop_table(*names) 342 options = names.last.is_a?(Hash) ? names.pop : OPTS 343 names.each do |n| 344 execute_ddl(drop_table_sql(n, options)) 345 remove_cached_schema(n) 346 end 347 nil 348 end
Drops the table if it already exists. If it doesn't exist, does nothing.
DB.drop_table?(:a) # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- if it already exists
# File lib/sequel/database/schema_methods.rb 356 def drop_table?(*names) 357 options = names.last.is_a?(Hash) ? names.pop : OPTS 358 if supports_drop_table_if_exists? 359 options = options.merge(:if_exists=>true) 360 names.each do |name| 361 drop_table(name, options) 362 end 363 else 364 names.each do |name| 365 drop_table(name, options) if table_exists?(name) 366 end 367 end 368 nil 369 end
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items) DB.drop_view(:cheap_items, :pricey_items) DB.drop_view(:cheap_items, :pricey_items, cascade: true) DB.drop_view(:cheap_items, :pricey_items, if_exists: true)
Options:
- :cascade
-
Also drop objects depending on this view.
- :if_exists
-
Do not raise an error if the view does not exist.
PostgreSQL specific options:
- :materialized
-
Drop a materialized view.
# File lib/sequel/database/schema_methods.rb 384 def drop_view(*names) 385 options = names.last.is_a?(Hash) ? names.pop : OPTS 386 names.each do |n| 387 execute_ddl(drop_view_sql(n, options)) 388 remove_cached_schema(n) 389 end 390 nil 391 end
Renames a column in the specified table. This method expects the current column name and the new column name:
DB.rename_column :items, :cntr, :counter
See alter_table
.
# File lib/sequel/database/schema_methods.rb 410 def rename_column(table, *args) 411 alter_table(table) {rename_column(*args)} 412 end
Renames a table:
DB.tables #=> [:items] DB.rename_table :items, :old_items DB.tables #=> [:old_items]
# File lib/sequel/database/schema_methods.rb 398 def rename_table(name, new_name) 399 execute_ddl(rename_table_sql(name, new_name)) 400 remove_cached_schema(name) 401 nil 402 end
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 419 def set_column_default(table, *args) 420 alter_table(table) {set_column_default(*args)} 421 end
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table
.
# File lib/sequel/database/schema_methods.rb 428 def set_column_type(table, *args) 429 alter_table(table) {set_column_type(*args)} 430 end
Private Instance Methods
# File lib/sequel/database/schema_methods.rb 468 def alter_table_add_column_sql(table, op) 469 "ADD COLUMN #{column_definition_sql(op)}" 470 end
# File lib/sequel/database/schema_methods.rb 492 def alter_table_add_constraint_sql(table, op) 493 "ADD #{constraint_definition_sql(op)}" 494 end
# File lib/sequel/database/schema_methods.rb 472 def alter_table_drop_column_sql(table, op) 473 "DROP COLUMN #{quote_identifier(op[:name])}#{' CASCADE' if op[:cascade]}" 474 end
# File lib/sequel/database/schema_methods.rb 496 def alter_table_drop_constraint_sql(table, op) 497 quoted_name = quote_identifier(op[:name]) if op[:name] 498 if op[:type] == :foreign_key 499 quoted_name ||= quote_identifier(foreign_key_name(table, op[:columns])) 500 end 501 "DROP CONSTRAINT #{quoted_name}#{' CASCADE' if op[:cascade]}" 502 end
The class used for alter_table
generators.
# File lib/sequel/database/schema_methods.rb 453 def alter_table_generator_class 454 Schema::AlterTableGenerator 455 end
SQL fragment for given alter table operation.
# File lib/sequel/database/schema_methods.rb 458 def alter_table_op_sql(table, op) 459 meth = "alter_table_#{op[:op]}_sql" 460 if respond_to?(meth, true) 461 # Allow calling private methods as alter table op sql methods are private 462 send(meth, table, op) 463 else 464 raise Error, "Unsupported ALTER TABLE operation: #{op[:op]}" 465 end 466 end
# File lib/sequel/database/schema_methods.rb 476 def alter_table_rename_column_sql(table, op) 477 "RENAME COLUMN #{quote_identifier(op[:name])} TO #{quote_identifier(op[:new_name])}" 478 end
# File lib/sequel/database/schema_methods.rb 484 def alter_table_set_column_default_sql(table, op) 485 "ALTER COLUMN #{quote_identifier(op[:name])} SET DEFAULT #{literal(op[:default])}" 486 end
# File lib/sequel/database/schema_methods.rb 488 def alter_table_set_column_null_sql(table, op) 489 "ALTER COLUMN #{quote_identifier(op[:name])} #{op[:null] ? 'DROP' : 'SET'} NOT NULL" 490 end
# File lib/sequel/database/schema_methods.rb 480 def alter_table_set_column_type_sql(table, op) 481 "ALTER COLUMN #{quote_identifier(op[:name])} TYPE #{type_literal(op)}" 482 end
The SQL to execute to modify the table. op should be one of the operations returned by the AlterTableGenerator.
# File lib/sequel/database/schema_methods.rb 506 def alter_table_sql(table, op) 507 case op[:op] 508 when :add_index 509 index_definition_sql(table, op) 510 when :drop_index 511 drop_index_sql(table, op) 512 else 513 if sql = alter_table_op_sql(table, op) 514 "ALTER TABLE #{quote_schema_table(table)} #{sql}" 515 end 516 end 517 end
Array
of SQL statements used to modify the table, corresponding to changes specified by the operations.
# File lib/sequel/database/schema_methods.rb 521 def alter_table_sql_list(table, operations) 522 if supports_combining_alter_table_ops? 523 grouped_ops = [] 524 last_combinable = false 525 operations.each do |op| 526 if combinable_alter_table_op?(op) 527 if sql = alter_table_op_sql(table, op) 528 grouped_ops << [] unless last_combinable 529 grouped_ops.last << sql 530 last_combinable = true 531 end 532 elsif sql = alter_table_sql(table, op) 533 Array(sql).each{|s| grouped_ops << s} 534 last_combinable = false 535 end 536 end 537 grouped_ops.map do |gop| 538 if gop.is_a?(Array) 539 "ALTER TABLE #{quote_schema_table(table)} #{gop.join(', ')}" 540 else 541 gop 542 end 543 end 544 else 545 operations.map{|op| alter_table_sql(table, op)}.flatten.compact 546 end 547 end
Apply the changes in the given alter table ops to the table given by name.
# File lib/sequel/database/schema_methods.rb 435 def apply_alter_table(name, ops) 436 alter_table_sql_list(name, ops).each{|sql| execute_ddl(sql)} 437 end
Apply the operations in the given generator to the table given by name.
# File lib/sequel/database/schema_methods.rb 440 def apply_alter_table_generator(name, generator) 441 ops = generator.operations 442 443 unless can_add_primary_key_constraint_on_nullable_columns? 444 if add_pk = ops.find{|op| op[:op] == :add_constraint && op[:type] == :primary_key} 445 ops = add_pk[:columns].map{|column| {:op => :set_column_null, :name => column, :null => false}} + ops 446 end 447 end 448 449 apply_alter_table(name, ops) 450 end
The SQL string specify the autoincrement property, generally used by primary keys.
# File lib/sequel/database/schema_methods.rb 551 def auto_increment_sql 552 'AUTOINCREMENT' 553 end
Add auto increment SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 569 def column_definition_auto_increment_sql(sql, column) 570 sql << " #{auto_increment_sql}" if column[:auto_increment] 571 end
Add collate SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 574 def column_definition_collate_sql(sql, column) 575 if collate = column[:collate] 576 sql << " COLLATE #{collate}" 577 end 578 end
Add default SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 581 def column_definition_default_sql(sql, column) 582 sql << " DEFAULT #{literal(column[:default])}" if column.include?(:default) 583 end
Add null/not null SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 586 def column_definition_null_sql(sql, column) 587 null = column.fetch(:null, column[:allow_null]) 588 if null.nil? && !can_add_primary_key_constraint_on_nullable_columns? && column[:primary_key] 589 null = false 590 end 591 592 case null 593 when false 594 sql << ' NOT NULL' 595 when true 596 sql << ' NULL' 597 end 598 end
The order of the column definition, as an array of symbols.
# File lib/sequel/database/schema_methods.rb 556 def column_definition_order 557 COLUMN_DEFINITION_ORDER 558 end
Add primary key SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 601 def column_definition_primary_key_sql(sql, column) 602 if column[:primary_key] 603 if name = column[:primary_key_constraint_name] 604 sql << " CONSTRAINT #{quote_identifier(name)}" 605 end 606 sql << " " << primary_key_constraint_sql_fragment(column) 607 constraint_deferrable_sql_append(sql, column[:primary_key_deferrable]) 608 end 609 end
Add foreign key reference SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 612 def column_definition_references_sql(sql, column) 613 if column[:table] 614 if name = column[:foreign_key_constraint_name] 615 sql << " CONSTRAINT #{quote_identifier(name)}" 616 end 617 sql << column_references_column_constraint_sql(column) 618 end 619 end
SQL fragment containing the column creation SQL for the given column.
# File lib/sequel/database/schema_methods.rb 561 def column_definition_sql(column) 562 sql = String.new 563 sql << "#{quote_identifier(column[:name])} #{type_literal(column)}" 564 column_definition_order.each{|m| send(:"column_definition_#{m}_sql", sql, column)} 565 sql 566 end
Add unique constraint SQL fragment to column creation SQL.
# File lib/sequel/database/schema_methods.rb 622 def column_definition_unique_sql(sql, column) 623 if column[:unique] 624 if name = column[:unique_constraint_name] 625 sql << " CONSTRAINT #{quote_identifier(name)}" 626 end 627 sql << ' ' << unique_constraint_sql_fragment(column) 628 constraint_deferrable_sql_append(sql, column[:unique_deferrable]) 629 end 630 end
SQL for all given columns, used inside a CREATE TABLE block.
# File lib/sequel/database/schema_methods.rb 633 def column_list_sql(generator) 634 (generator.columns.map{|c| column_definition_sql(c)} + generator.constraints.map{|c| constraint_definition_sql(c)}).join(', ') 635 end
SQL fragment for column foreign key references (column constraints)
# File lib/sequel/database/schema_methods.rb 638 def column_references_column_constraint_sql(column) 639 column_references_sql(column) 640 end
SQL fragment for column foreign key references
# File lib/sequel/database/schema_methods.rb 643 def column_references_sql(column) 644 sql = String.new 645 sql << " REFERENCES #{quote_schema_table(column[:table])}" 646 sql << "(#{Array(column[:key]).map{|x| quote_identifier(x)}.join(', ')})" if column[:key] 647 sql << " ON DELETE #{on_delete_clause(column[:on_delete])}" if column[:on_delete] 648 sql << " ON UPDATE #{on_update_clause(column[:on_update])}" if column[:on_update] 649 constraint_deferrable_sql_append(sql, column[:deferrable]) 650 sql 651 end
SQL fragment for table foreign key references (table constraints)
# File lib/sequel/database/schema_methods.rb 654 def column_references_table_constraint_sql(constraint) 655 "FOREIGN KEY #{literal(constraint[:columns])}#{column_references_sql(constraint)}" 656 end
Whether the given alter table operation is combinable.
# File lib/sequel/database/schema_methods.rb 659 def combinable_alter_table_op?(op) 660 COMBINABLE_ALTER_TABLE_OPS.include?(op[:op]) 661 end
SQL fragment specifying the deferrable constraint attributes.
# File lib/sequel/database/schema_methods.rb 688 def constraint_deferrable_sql_append(sql, defer) 689 case defer 690 when nil 691 when false 692 sql << ' NOT DEFERRABLE' 693 when :immediate 694 sql << ' DEFERRABLE INITIALLY IMMEDIATE' 695 else 696 sql << ' DEFERRABLE INITIALLY DEFERRED' 697 end 698 end
SQL fragment specifying a constraint on a table.
# File lib/sequel/database/schema_methods.rb 664 def constraint_definition_sql(constraint) 665 sql = String.new 666 sql << "CONSTRAINT #{quote_identifier(constraint[:name])} " if constraint[:name] 667 case constraint[:type] 668 when :check 669 check = constraint[:check] 670 check = check.first if check.is_a?(Array) && check.length == 1 671 check = filter_expr(check) 672 check = "(#{check})" unless check[0..0] == '(' && check[-1..-1] == ')' 673 sql << "CHECK #{check}" 674 when :primary_key 675 sql << "#{primary_key_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}" 676 when :foreign_key 677 sql << column_references_table_constraint_sql(constraint.merge(:deferrable=>nil)) 678 when :unique 679 sql << "#{unique_constraint_sql_fragment(constraint)} #{literal(constraint[:columns])}" 680 else 681 raise Error, "Invalid constraint type #{constraint[:type]}, should be :check, :primary_key, :foreign_key, or :unique" 682 end 683 constraint_deferrable_sql_append(sql, constraint[:deferrable]) 684 sql 685 end
Run SQL statement to create the table with the given name from the given SELECT sql statement.
# File lib/sequel/database/schema_methods.rb 758 def create_table_as(name, sql, options) 759 sql = sql.sql if sql.is_a?(Sequel::Dataset) 760 run(create_table_as_sql(name, sql, options)) 761 end
SQL statement for creating a table from the result of a SELECT statement. sql
should be a string representing a SELECT query.
# File lib/sequel/database/schema_methods.rb 765 def create_table_as_sql(name, sql, options) 766 "#{create_table_prefix_sql(name, options)} AS #{sql}" 767 end
Execute the create table statements using the generator.
# File lib/sequel/database/schema_methods.rb 701 def create_table_from_generator(name, generator, options) 702 execute_ddl(create_table_sql(name, generator, options)) 703 end
The class used for create_table
generators.
# File lib/sequel/database/schema_methods.rb 706 def create_table_generator_class 707 Schema::CreateTableGenerator 708 end
Execute the create index statements using the generator.
# File lib/sequel/database/schema_methods.rb 711 def create_table_indexes_from_generator(name, generator, options) 712 e = options[:ignore_index_errors] || options[:if_not_exists] 713 generator.indexes.each do |index| 714 begin 715 pr = proc{index_sql_list(name, [index]).each{|sql| execute_ddl(sql)}} 716 supports_transactional_ddl? ? transaction(:savepoint=>:only, &pr) : pr.call 717 rescue Error 718 raise unless e 719 end 720 end 721 end
SQL fragment for initial part of CREATE TABLE statement
# File lib/sequel/database/schema_methods.rb 770 def create_table_prefix_sql(name, options) 771 "CREATE #{temporary_table_sql if options[:temp]}TABLE#{' IF NOT EXISTS' if options[:if_not_exists]} #{options[:temp] ? quote_identifier(name) : quote_schema_table(name)}" 772 end
SQL statement for creating a table with the given name, columns, and options
# File lib/sequel/database/schema_methods.rb 724 def create_table_sql(name, generator, options) 725 unless supports_named_column_constraints? 726 # Split column constraints into table constraints if they have a name 727 generator.columns.each do |c| 728 if (constraint_name = c.delete(:foreign_key_constraint_name)) && (table = c.delete(:table)) 729 opts = {} 730 opts[:name] = constraint_name 731 [:key, :on_delete, :on_update, :deferrable].each{|k| opts[k] = c[k]} 732 generator.foreign_key([c[:name]], table, opts) 733 end 734 if (constraint_name = c.delete(:unique_constraint_name)) && c.delete(:unique) 735 generator.unique(c[:name], :name=>constraint_name) 736 end 737 if (constraint_name = c.delete(:primary_key_constraint_name)) && c.delete(:primary_key) 738 generator.primary_key([c[:name]], :name=>constraint_name) 739 end 740 end 741 end 742 743 unless can_add_primary_key_constraint_on_nullable_columns? 744 if pk = generator.constraints.find{|op| op[:type] == :primary_key} 745 pk[:columns].each do |column| 746 if matched_column = generator.columns.find{|gc| gc[:name] == column} 747 matched_column[:null] = false 748 end 749 end 750 end 751 end 752 753 "#{create_table_prefix_sql(name, options)} (#{column_list_sql(generator)})" 754 end
SQL fragment for initial part of CREATE VIEW statement
# File lib/sequel/database/schema_methods.rb 775 def create_view_prefix_sql(name, options) 776 create_view_sql_append_columns("CREATE #{'OR REPLACE 'if options[:replace]}VIEW #{quote_schema_table(name)}", options[:columns]) 777 end
SQL statement for creating a view.
# File lib/sequel/database/schema_methods.rb 780 def create_view_sql(name, source, options) 781 source = source.sql if source.is_a?(Dataset) 782 sql = String.new 783 sql << "#{create_view_prefix_sql(name, options)} AS #{source}" 784 if check = options[:check] 785 sql << " WITH#{' LOCAL' if check == :local} CHECK OPTION" 786 end 787 sql 788 end
Append the column list to the SQL, if a column list is given.
# File lib/sequel/database/schema_methods.rb 791 def create_view_sql_append_columns(sql, columns) 792 if columns 793 sql += ' (' 794 schema_utility_dataset.send(:identifier_list_append, sql, columns) 795 sql << ')' 796 end 797 sql 798 end
Default index name for the table and columns, may be too long for certain databases.
# File lib/sequel/database/schema_methods.rb 802 def default_index_name(table_name, columns) 803 schema, table = schema_and_table(table_name) 804 "#{"#{schema}_" if schema}#{table}_#{columns.map{|c| [String, Symbol].any?{|cl| c.is_a?(cl)} ? c : literal(c).gsub(/\W/, '_')}.join('_')}_index" 805 end
The SQL to drop an index for the table.
# File lib/sequel/database/schema_methods.rb 815 def drop_index_sql(table, op) 816 "DROP INDEX #{quote_identifier(op[:name] || default_index_name(table, op[:columns]))}" 817 end
SQL DDL statement to drop the table with the given name.
# File lib/sequel/database/schema_methods.rb 820 def drop_table_sql(name, options) 821 "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 822 end
SQL DDL statement to drop a view with the given name.
# File lib/sequel/database/schema_methods.rb 825 def drop_view_sql(name, options) 826 "DROP VIEW#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 827 end
Proxy the filter_expr
call to the dataset, used for creating constraints. Support passing Proc arguments as blocks, as well as treating plain strings as literal strings, so that previous migrations that used this API do not break.
# File lib/sequel/database/schema_methods.rb 832 def filter_expr(arg=nil, &block) 833 if arg.is_a?(Proc) && !block 834 block = arg 835 arg = nil 836 elsif arg.is_a?(String) 837 arg = Sequel.lit(arg) 838 elsif arg.is_a?(Array) 839 if arg.first.is_a?(String) 840 arg = Sequel.lit(*arg) 841 elsif arg.length > 1 842 arg = Sequel.&(*arg) 843 end 844 end 845 schema_utility_dataset.literal(schema_utility_dataset.send(:filter_expr, arg, &block)) 846 end
Get foreign key name for given table and columns.
# File lib/sequel/database/schema_methods.rb 808 def foreign_key_name(table_name, columns) 809 keys = foreign_key_list(table_name).select{|key| key[:columns] == columns} 810 raise(Error, "#{keys.empty? ? 'Missing' : 'Ambiguous'} foreign key for #{columns.inspect}") unless keys.size == 1 811 keys.first[:name] 812 end
SQL statement for creating an index for the table with the given name and index specifications.
# File lib/sequel/database/schema_methods.rb 850 def index_definition_sql(table_name, index) 851 index_name = index[:name] || default_index_name(table_name, index[:columns]) 852 raise Error, "Index types are not supported for this database" if index[:type] 853 raise Error, "Partial indexes are not supported for this database" if index[:where] && !supports_partial_indexes? 854 "CREATE #{'UNIQUE ' if index[:unique]}INDEX #{quote_identifier(index_name)} ON #{quote_schema_table(table_name)} #{literal(index[:columns])}#{" WHERE #{filter_expr(index[:where])}" if index[:where]}" 855 end
Array
of SQL statements, one for each index specification, for the given table.
# File lib/sequel/database/schema_methods.rb 859 def index_sql_list(table_name, indexes) 860 indexes.map{|i| index_definition_sql(table_name, i)} 861 end
Extract the join table name from the arguments given to create_join_table. Also does argument validation for the create_join_table
method.
# File lib/sequel/database/schema_methods.rb 865 def join_table_name(hash, options) 866 entries = hash.values 867 raise Error, "must have 2 entries in hash given to (create|drop)_join_table" unless entries.length == 2 868 if options[:name] 869 options[:name] 870 else 871 table_names = entries.map{|e| join_table_name_extract(e)} 872 table_names.map(&:to_s).sort.join('_') 873 end 874 end
Extract an individual join table name, which should either be a string or symbol, or a hash containing one of those as the value for :table.
# File lib/sequel/database/schema_methods.rb 878 def join_table_name_extract(entry) 879 case entry 880 when Symbol, String 881 entry 882 when Hash 883 join_table_name_extract(entry[:table]) 884 else 885 raise Error, "can't extract table name from #{entry.inspect}" 886 end 887 end
SQL fragment to use for ON DELETE, based on the given action. The following actions are recognized:
- :cascade
-
Delete rows referencing this row.
- :no_action
-
Raise an error if other rows reference this row, allow deferring of the integrity check. This is the default.
- :restrict
-
Raise an error if other rows reference this row, but do not allow deferring the integrity check.
- :set_default
-
Set columns referencing this row to their default value.
- :set_null
-
Set columns referencing this row to NULL.
Any other object given is just converted to a string, with “_” converted to “ ” and upcased.
# File lib/sequel/database/schema_methods.rb 902 def on_delete_clause(action) 903 action.to_s.gsub("_", " ").upcase 904 end
Alias of on_delete_clause
, since the two usually behave the same.
# File lib/sequel/database/schema_methods.rb 907 def on_update_clause(action) 908 on_delete_clause(action) 909 end
Add fragment for primary key specification, separated for easier overridding.
Proxy the quote_schema_table
method to the dataset
# File lib/sequel/database/schema_methods.rb 917 def quote_schema_table(table) 918 schema_utility_dataset.quote_schema_table(table) 919 end
SQL statement for renaming a table.
# File lib/sequel/database/schema_methods.rb 922 def rename_table_sql(name, new_name) 923 "ALTER TABLE #{quote_schema_table(name)} RENAME TO #{quote_schema_table(new_name)}" 924 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 927 def schema_and_table(table_name) 928 schema_utility_dataset.schema_and_table(table_name) 929 end
Return true if the given column schema represents an autoincrementing primary key.
# File lib/sequel/database/schema_methods.rb 932 def schema_autoincrementing_primary_key?(schema) 933 !!(schema[:primary_key] && schema[:auto_increment]) 934 end
The dataset to use for proxying certain schema methods.
# File lib/sequel/database/schema_methods.rb 937 def schema_utility_dataset 938 @default_dataset 939 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 942 def split_qualifiers(table_name) 943 schema_utility_dataset.split_qualifiers(table_name) 944 end
SQL fragment for temporary table
# File lib/sequel/database/schema_methods.rb 947 def temporary_table_sql 948 'TEMPORARY ' 949 end
SQL fragment specifying the type of a given column.
# File lib/sequel/database/schema_methods.rb 952 def type_literal(column) 953 case column[:type] 954 when Class 955 type_literal_generic(column) 956 when :Bignum 957 type_literal_generic_bignum_symbol(column) 958 else 959 type_literal_specific(column) 960 end 961 end
SQL fragment specifying the full type of a column, consider the type with possible modifiers.
# File lib/sequel/database/schema_methods.rb 965 def type_literal_generic(column) 966 meth = "type_literal_generic_#{column[:type].name.to_s.downcase}" 967 if respond_to?(meth, true) 968 # Allow calling private methods as per type literal generic methods are private 969 send(meth, column) 970 else 971 raise Error, "Unsupported ruby class used as database type: #{column[:type]}" 972 end 973 end
Alias for type_literal_generic_numeric
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 976 def type_literal_generic_bigdecimal(column) 977 type_literal_generic_numeric(column) 978 end
Sequel
uses the bigint type by default for :Bignum symbol.
# File lib/sequel/database/schema_methods.rb 981 def type_literal_generic_bignum_symbol(column) 982 :bigint 983 end
Sequel
uses the date type by default for Dates.
# File lib/sequel/database/schema_methods.rb 986 def type_literal_generic_date(column) 987 :date 988 end
Sequel
uses the timestamp type by default for DateTimes.
# File lib/sequel/database/schema_methods.rb 991 def type_literal_generic_datetime(column) 992 :timestamp 993 end
Alias for type_literal_generic_trueclass
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 996 def type_literal_generic_falseclass(column) 997 type_literal_generic_trueclass(column) 998 end
Sequel
uses the blob type by default for Files.
# File lib/sequel/database/schema_methods.rb 1001 def type_literal_generic_file(column) 1002 :blob 1003 end
Alias for type_literal_generic_integer
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 1006 def type_literal_generic_fixnum(column) 1007 type_literal_generic_integer(column) 1008 end
Sequel
uses the double precision type by default for Floats.
# File lib/sequel/database/schema_methods.rb 1011 def type_literal_generic_float(column) 1012 :"double precision" 1013 end
Sequel
uses the integer type by default for integers
# File lib/sequel/database/schema_methods.rb 1016 def type_literal_generic_integer(column) 1017 :integer 1018 end
Sequel
uses the numeric type by default for Numerics and BigDecimals. If a size is given, it is used, otherwise, it will default to whatever the database default is for an unsized value.
# File lib/sequel/database/schema_methods.rb 1023 def type_literal_generic_numeric(column) 1024 column[:size] ? "numeric(#{Array(column[:size]).join(', ')})" : :numeric 1025 end
Use time by default for Time values if :only_time option is used.
# File lib/sequel/database/schema_methods.rb 1052 def type_literal_generic_only_time(column) 1053 :time 1054 end
Sequel
uses the varchar type by default for Strings. If a size isn't present, Sequel
assumes a size of 255. If the :fixed option is used, Sequel
uses the char type. If the :text option is used, Sequel
uses the :text type.
# File lib/sequel/database/schema_methods.rb 1031 def type_literal_generic_string(column) 1032 if column[:text] 1033 uses_clob_for_text? ? :clob : :text 1034 elsif column[:fixed] 1035 "char(#{column[:size]||default_string_column_size})" 1036 else 1037 "varchar(#{column[:size]||default_string_column_size})" 1038 end 1039 end
Sequel
uses the timestamp type by default for Time values. If the :only_time option is used, the time type is used.
# File lib/sequel/database/schema_methods.rb 1043 def type_literal_generic_time(column) 1044 if column[:only_time] 1045 type_literal_generic_only_time(column) 1046 else 1047 type_literal_generic_datetime(column) 1048 end 1049 end
Sequel
uses the boolean type by default for TrueClass
and FalseClass
.
# File lib/sequel/database/schema_methods.rb 1057 def type_literal_generic_trueclass(column) 1058 :boolean 1059 end
SQL fragment for the given type of a column if the column is not one of the generic types specified with a ruby class.
# File lib/sequel/database/schema_methods.rb 1063 def type_literal_specific(column) 1064 type = column[:type] 1065 type = "double precision" if type.to_s == 'double' 1066 column[:size] ||= default_string_column_size if type.to_s == 'varchar' 1067 elements = column[:size] || column[:elements] 1068 "#{type}#{literal(Array(elements)) if elements}#{' UNSIGNED' if column[:unsigned]}" 1069 end
Add fragment for unique specification, separated for easier overridding.
# File lib/sequel/database/schema_methods.rb 1072 def unique_constraint_sql_fragment(_) 1073 'UNIQUE' 1074 end
Whether clob should be used for String
text: true columns.
# File lib/sequel/database/schema_methods.rb 1077 def uses_clob_for_text? 1078 false 1079 end
3 - Methods that create datasets
↑ topPublic Instance Methods
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch
, returning a dataset for arbitrary SQL, with or without placeholders:
DB['SELECT * FROM items'].all DB['SELECT * FROM items WHERE name = ?', my_name].all
Otherwise, acts as an alias for Database#from
, setting the primary table for the dataset:
DB[:items].sql #=> "SELECT * FROM items"
# File lib/sequel/database/dataset.rb 21 def [](*args) 22 args.first.is_a?(String) ? fetch(*args) : from(*args) 23 end
Returns a blank dataset for this database.
DB.dataset # SELECT * DB.dataset.from(:items) # SELECT * FROM items
# File lib/sequel/database/dataset.rb 29 def dataset 30 @dataset_class.new(self) 31 end
Fetches records for an arbitrary SQL statement. If a block is given, it is used to iterate over the records:
DB.fetch('SELECT * FROM items'){|r| p r}
The fetch
method returns a dataset instance:
DB.fetch('SELECT * FROM items').all
fetch
can also perform parameterized queries for protection against SQL injection:
DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all
See caveats listed in Dataset#with_sql regarding datasets using custom SQL and the methods that can be called on them.
# File lib/sequel/database/dataset.rb 49 def fetch(sql, *args, &block) 50 ds = @default_dataset.with_sql(sql, *args) 51 ds.each(&block) if block 52 ds 53 end
Returns a new dataset with the from
method invoked. If a block is given, it acts as a virtual row block
DB.from(:items) # SELECT * FROM items DB.from{schema[:table]} # SELECT * FROM schema.table
# File lib/sequel/database/dataset.rb 60 def from(*args, &block) 61 if block 62 @default_dataset.from(*args, &block) 63 elsif args.length == 1 && (table = args[0]).is_a?(Symbol) 64 @default_dataset.send(:cached_dataset, :"_from_#{table}_ds"){@default_dataset.from(table)} 65 else 66 @default_dataset.from(*args) 67 end 68 end
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1 DB.select{server_version.function} # SELECT server_version() DB.select(:id).from(:items) # SELECT id FROM items
# File lib/sequel/database/dataset.rb 75 def select(*args, &block) 76 @default_dataset.select(*args, &block) 77 end
4 - Methods relating to adapters, connecting, disconnecting, and sharding
↑ topConstants
- ADAPTERS
Array
of supported database adapters
Attributes
Public Class Methods
The Database
subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
# File lib/sequel/database/connecting.rb 16 def self.adapter_class(scheme) 17 scheme.is_a?(Class) ? scheme : load_adapter(scheme.to_sym) 18 end
Returns the scheme symbol for the Database
class.
# File lib/sequel/database/connecting.rb 21 def self.adapter_scheme 22 @scheme 23 end
Connects to a database. See Sequel.connect.
# File lib/sequel/database/connecting.rb 26 def self.connect(conn_string, opts = OPTS) 27 case conn_string 28 when String 29 if conn_string.start_with?('jdbc:') 30 c = adapter_class(:jdbc) 31 opts = opts.merge(:orig_opts=>opts.dup) 32 opts = {:uri=>conn_string}.merge!(opts) 33 else 34 uri = URI.parse(conn_string) 35 scheme = uri.scheme 36 c = adapter_class(scheme) 37 uri_options = c.send(:uri_to_options, uri) 38 uri.query.split('&').map{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? 39 uri_options.to_a.each{|k,v| uri_options[k] = URI::DEFAULT_PARSER.unescape(v) if v.is_a?(String)} 40 opts = uri_options.merge(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme) 41 end 42 when Hash 43 opts = conn_string.merge(opts) 44 opts = opts.merge(:orig_opts=>opts.dup) 45 c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) 46 else 47 raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" 48 end 49 50 opts = opts.inject({}) do |m, (k,v)| 51 k = :user if k.to_s == 'username' 52 m[k.to_sym] = v 53 m 54 end 55 56 begin 57 db = c.new(opts) 58 if defined?(yield) 59 return yield(db) 60 end 61 ensure 62 if defined?(yield) 63 db.disconnect if db 64 Sequel.synchronize{::Sequel::DATABASES.delete(db)} 65 end 66 end 67 db 68 end
Load the adapter from the file system. Raises Sequel::AdapterNotFound if the adapter cannot be loaded, or if the adapter isn't registered correctly after being loaded. Options:
- :map
-
The
Hash
in which to look for an already loaded adapter (defaults to ADAPTER_MAP). - :subdir
-
The subdirectory of sequel/adapters to look in, only to be used for loading subadapters.
# File lib/sequel/database/connecting.rb 76 def self.load_adapter(scheme, opts=OPTS) 77 map = opts[:map] || ADAPTER_MAP 78 if subdir = opts[:subdir] 79 file = "#{subdir}/#{scheme}" 80 else 81 file = scheme 82 end 83 84 unless obj = Sequel.synchronize{map[scheme]} 85 # attempt to load the adapter file 86 begin 87 require "sequel/adapters/#{file}" 88 rescue LoadError => e 89 # If subadapter file doesn't exist, just return, 90 # using the main adapter class without database customizations. 91 return if subdir 92 raise Sequel.convert_exception_class(e, AdapterNotFound) 93 end 94 95 # make sure we actually loaded the adapter 96 unless obj = Sequel.synchronize{map[scheme]} 97 raise AdapterNotFound, "Could not load #{file} adapter: adapter class not registered in ADAPTER_MAP" 98 end 99 end 100 101 obj 102 end
Public Instance Methods
Returns the scheme symbol for this instance's class, which reflects which adapter is being used. In some cases, this can be the same as the database_type
(for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme # => :jdbc
# File lib/sequel/database/connecting.rb 161 def adapter_scheme 162 self.class.adapter_scheme 163 end
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Only usable when using a sharded connection pool.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it's value is overridden with the value provided.
DB.add_servers(f: {host: "hash_host_f"})
# File lib/sequel/database/connecting.rb 173 def add_servers(servers) 174 unless sharded? 175 raise Error, "cannot call Database#add_servers on a Database instance that does not use a sharded connection pool" 176 end 177 178 h = @opts[:servers] 179 Sequel.synchronize{h.merge!(servers)} 180 @pool.add_servers(servers.keys) 181 end
The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database
objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database
objects that are using the same adapter are connecting to different database types.
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
# File lib/sequel/database/connecting.rb 192 def database_type 193 adapter_scheme 194 end
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
- :server
-
Should be a symbol specifing the server to disconnect from,
or an array of symbols to specify multiple servers.
Example:
DB.disconnect # All servers DB.disconnect(server: :server1) # Single server DB.disconnect(server: [:server1, :server2]) # Multiple servers
# File lib/sequel/database/connecting.rb 206 def disconnect(opts = OPTS) 207 pool.disconnect(opts) 208 end
Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.
# File lib/sequel/database/connecting.rb 213 def disconnect_connection(conn) 214 conn.close 215 end
Connect to the given server/shard. Handles database-generic post-connection setup not handled by connect, using the :after_connect and :connect_sqls options.
# File lib/sequel/database/connecting.rb 247 def new_connection(server) 248 conn = connect(server) 249 opts = server_opts(server) 250 251 if ac = opts[:after_connect] 252 if ac.arity == 2 253 ac.call(conn, server) 254 else 255 ac.call(conn) 256 end 257 end 258 259 if cs = opts[:connect_sqls] 260 cs.each do |sql| 261 log_connection_execute(conn, sql) 262 end 263 end 264 265 conn 266 end
Dynamically remove existing servers from the connection pool. Only usable when using a sharded connection pool
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
# File lib/sequel/database/connecting.rb 226 def remove_servers(*servers) 227 unless sharded? 228 raise Error, "cannot call Database#remove_servers on a Database instance that does not use a sharded connection pool" 229 end 230 231 h = @opts[:servers] 232 servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} 233 @pool.remove_servers(servers) 234 end
An array of servers/shards for this Database
object.
DB.servers # Unsharded: => [:default] DB.servers # Sharded: => [:default, :server1, :server2]
# File lib/sequel/database/connecting.rb 240 def servers 241 pool.servers 242 end
Returns true if the database is using a single-threaded connection pool.
# File lib/sequel/database/connecting.rb 269 def single_threaded? 270 @single_threaded 271 end
:nocov:
# File lib/sequel/database/connecting.rb 275 def synchronize(server=nil) 276 @pool.hold(server || :default){|conn| yield conn} 277 end
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
# File lib/sequel/database/connecting.rb 301 def test_connection(server=nil) 302 synchronize(server){|conn|} 303 true 304 end
Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.
# File lib/sequel/database/connecting.rb 310 def valid_connection?(conn) 311 sql = valid_connection_sql 312 begin 313 log_connection_execute(conn, sql) 314 rescue Sequel::DatabaseError, *database_error_classes 315 false 316 else 317 true 318 end 319 end
Private Instance Methods
The default options for the connection pool.
# File lib/sequel/database/connecting.rb 324 def connection_pool_default_options 325 {} 326 end
Return the options for the given server by merging the generic options for all server with the specific options for the given server specified in the :servers option.
# File lib/sequel/database/connecting.rb 331 def server_opts(server) 332 opts = if @opts[:servers] and server_options = @opts[:servers][server] 333 case server_options 334 when Hash 335 @opts.merge(server_options) 336 when Proc 337 @opts.merge(server_options.call(self)) 338 else 339 raise Error, 'Server opts should be a hash or proc' 340 end 341 elsif server.is_a?(Hash) 342 @opts.merge(server) 343 else 344 @opts.dup 345 end 346 opts.delete(:servers) 347 opts 348 end
The SQL query to issue to check if a connection is valid.
# File lib/sequel/database/connecting.rb 351 def valid_connection_sql 352 @valid_connection_sql ||= select(nil).sql 353 end
5 - Methods that set defaults for created datasets
↑ topAttributes
The class to use for creating datasets. Should respond to new with the Database
argument as the first argument, and an optional options hash.
Public Instance Methods
If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.
# File lib/sequel/database/dataset_defaults.rb 18 def dataset_class=(c) 19 unless @dataset_modules.empty? 20 c = Class.new(c) 21 @dataset_modules.each{|m| c.send(:include, m)} 22 end 23 @dataset_class = c 24 reset_default_dataset 25 end
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class
as the new dataset_class
, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database
object uses.
If a block is given, a Dataset::DatasetModule instance is created, allowing for the easy creation of named dataset methods that will do caching.
Examples:
# Introspect columns for all of DB's datasets DB.extend_datasets(Sequel::ColumnsIntrospection) # Trace all SELECT queries by printing the SQL and the full backtrace DB.extend_datasets do def fetch_rows(sql) puts sql puts caller super end end # Add some named dataset methods DB.extend_datasets do order :by_id, :id select :with_id_and_name, :id, :name where :active, :active end DB[:table].active.with_id_and_name.by_id # SELECT id, name FROM table WHERE active ORDER BY id
# File lib/sequel/database/dataset_defaults.rb 62 def extend_datasets(mod=nil, &block) 63 raise(Error, "must provide either mod or block, not both") if mod && block 64 mod = Dataset::DatasetModule.new(&block) if block 65 if @dataset_modules.empty? 66 @dataset_modules = [mod] 67 @dataset_class = Class.new(@dataset_class) 68 else 69 @dataset_modules << mod 70 end 71 @dataset_class.send(:include, mod) 72 reset_default_dataset 73 end
Private Instance Methods
The default dataset class to use for the database
# File lib/sequel/database/dataset_defaults.rb 78 def dataset_class_default 79 Sequel::Dataset 80 end
Whether to quote identifiers by default for this database, true by default.
# File lib/sequel/database/dataset_defaults.rb 89 def quote_identifiers_default 90 true 91 end
Reset the default dataset used by most Database
methods that create datasets.
# File lib/sequel/database/dataset_defaults.rb 83 def reset_default_dataset 84 Sequel.synchronize{@symbol_literal_cache.clear} 85 @default_dataset = dataset 86 end
6 - Methods relating to logging
↑ topAttributes
Whether to include information about the connection in use when logging queries.
Numeric
specifying the duration beyond which queries are logged at warn level instead of info level.
Array
of SQL loggers to use for this database.
Log level at which to log SQL queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.
Public Instance Methods
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
# File lib/sequel/database/logging.rb 37 def log_connection_yield(sql, conn, args=nil) 38 return yield if skip_logging? 39 sql = "#{connection_info(conn) if conn && log_connection_info}#{sql}#{"; #{args.inspect}" if args}" 40 timer = Sequel.start_timer 41 42 begin 43 yield 44 rescue => e 45 log_exception(e, sql) 46 raise 47 ensure 48 log_duration(Sequel.elapsed_seconds_since(timer), sql) unless e 49 end 50 end
Log a message at error level, with information about the exception.
# File lib/sequel/database/logging.rb 26 def log_exception(exception, message) 27 log_each(:error, "#{exception.class}: #{exception.message.strip if exception.message}: #{message}") 28 end
Log a message at level info to all loggers.
# File lib/sequel/database/logging.rb 31 def log_info(message, args=nil) 32 log_each(:info, args ? "#{message}; #{args.inspect}" : message) 33 end
Remove any existing loggers and just use the given logger:
DB.logger = Logger.new($stdout)
# File lib/sequel/database/logging.rb 55 def logger=(logger) 56 @loggers = Array(logger) 57 end
Private Instance Methods
String
including information about the connection, for use when logging connection info.
# File lib/sequel/database/logging.rb 69 def connection_info(conn) 70 "(conn: #{conn.__id__}) " 71 end
Log the given SQL and then execute it on the connection, used by the transaction code.
# File lib/sequel/database/logging.rb 75 def log_connection_execute(conn, sql) 76 log_connection_yield(sql, conn){conn.public_send(connection_execute_method, sql)} 77 end
Log message with message prefixed by duration at info level, or warn level if duration is greater than log_warn_duration.
# File lib/sequel/database/logging.rb 81 def log_duration(duration, message) 82 log_each((lwd = log_warn_duration and duration >= lwd) ? :warn : sql_log_level, "(#{sprintf('%0.6fs', duration)}) #{message}") 83 end
Log message at level (which should be :error, :warn, or :info) to all loggers.
# File lib/sequel/database/logging.rb 87 def log_each(level, message) 88 @loggers.each{|logger| logger.public_send(level, message)} 89 end
Determine if logging should be skipped. Defaults to true if no loggers have been specified.
# File lib/sequel/database/logging.rb 63 def skip_logging? 64 @loggers.empty? 65 end
7 - Miscellaneous methods
↑ topConstants
- CHECK_CONSTRAINT_SQLSTATES
- DEFAULT_DATABASE_ERROR_REGEXPS
Empty exception regexp to class map, used by default if
Sequel
doesn't have specific support for the database in use.- DEFAULT_STRING_COLUMN_SIZE
The general default size for string columns for all
Sequel::Database
instances.- EXTENSIONS
Hash
of extension name symbols to callable objects to load the extension into theDatabase
object (usually by extending it with a module defined in the extension).- FOREIGN_KEY_CONSTRAINT_SQLSTATES
- NOT_NULL_CONSTRAINT_SQLSTATES
- SCHEMA_TYPE_CLASSES
Mapping of schema type symbols to class or arrays of classes for that symbol.
- SERIALIZATION_CONSTRAINT_SQLSTATES
- UNIQUE_CONSTRAINT_SQLSTATES
Attributes
Whether to check the bytesize of strings before typecasting (to avoid typecasting strings that would be too long for the given type), true by default. Strings that are too long will raise a typecasting error.
The specific default size of string columns for this Sequel::Database
, usually 255 by default.
The options hash for this database
Set the timezone to use for this database, overridding Sequel.database_timezone
.
Public Class Methods
Register a hook that will be run when a new Database
is instantiated. It is called with the new database handle.
# File lib/sequel/database/misc.rb 34 def self.after_initialize(&block) 35 raise Error, "must provide block to after_initialize" unless block 36 Sequel.synchronize do 37 previous = @initialize_hook 38 @initialize_hook = proc do |db| 39 previous.call(db) 40 block.call(db) 41 end 42 end 43 end
Apply an extension to all Database
objects created in the future.
# File lib/sequel/database/misc.rb 46 def self.extension(*extensions) 47 after_initialize{|db| db.extension(*extensions)} 48 end
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
- :after_connect
-
A callable object called after each new connection is made, with the connection object (and server argument if the callable accepts 2 arguments), useful for customizations that you want to apply to all connections.
- :before_preconnect
-
Callable that runs after extensions from :preconnect_extensions are loaded, but before any connections are created.
- :cache_schema
-
Whether schema should be cached for this
Database
instance - :check_string_typecast_bytesize
-
Whether to check the bytesize of strings before typecasting.
- :connect_sqls
-
An array of sql strings to execute on each new connection, after :after_connect runs.
- :default_string_column_size
-
The default size of string columns, 255 by default.
- :extensions
-
Extensions to load into this
Database
instance. Can be a symbol, array of symbols, or string with extensions separated by columns. These extensions are loaded after connections are made by the :preconnect option. - :keep_reference
-
Whether to keep a reference to this instance in Sequel::DATABASES, true by default.
- :logger
-
A specific logger to use.
- :loggers
-
An array of loggers to use.
- :log_connection_info
-
Whether connection information should be logged when logging queries.
- :log_warn_duration
-
The number of elapsed seconds after which queries should be logged at warn level.
- :name
-
A name to use for the
Database
object, displayed in PoolTimeout. - :preconnect
-
Automatically create the maximum number of connections, so that they don't need to be created as needed. This is useful when connecting takes a long time and you want to avoid possible latency during runtime. Set to :concurrently to create the connections in separate threads. Otherwise they'll be created sequentially.
- :preconnect_extensions
-
Similar to the :extensions option, but loads the extensions before the connections are made by the :preconnect option.
- :quote_identifiers
-
Whether to quote identifiers.
- :servers
-
A hash specifying a server/shard specific options, keyed by shard symbol.
- :single_threaded
-
Whether to use a single-threaded connection pool.
- :sql_log_level
-
Method to use to log SQL to a logger, :info by default.
For sharded connection pools, :after_connect and :connect_sqls can be specified per-shard.
All options given are also passed to the connection pool. Additional options respected by the connection pool are :max_connections, :pool_timeout, :servers, and :servers_hash. See the connection pool documentation for details.
# File lib/sequel/database/misc.rb 138 def initialize(opts = OPTS) 139 @opts ||= opts 140 @opts = connection_pool_default_options.merge(@opts) 141 @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) 142 @opts[:servers] = {} if @opts[:servers].is_a?(String) 143 @sharded = !!@opts[:servers] 144 @opts[:adapter_class] = self.class 145 @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Sequel.single_threaded)) 146 @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE 147 @check_string_typecast_bytesize = typecast_value_boolean(@opts.fetch(:check_string_typecast_bytesize, true)) 148 149 @schemas = {} 150 @prepared_statements = {} 151 @transactions = {} 152 @symbol_literal_cache = {} 153 154 @timezone = nil 155 156 @dataset_class = dataset_class_default 157 @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) 158 @dataset_modules = [] 159 @loaded_extensions = [] 160 @schema_type_classes = SCHEMA_TYPE_CLASSES.dup 161 162 self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info 163 self.log_warn_duration = @opts[:log_warn_duration] 164 self.log_connection_info = typecast_value_boolean(@opts[:log_connection_info]) 165 166 @pool = ConnectionPool.get_pool(self, @opts) 167 168 reset_default_dataset 169 adapter_initialize 170 171 keep_reference = typecast_value_boolean(@opts[:keep_reference]) != false 172 begin 173 Sequel.synchronize{::Sequel::DATABASES.push(self)} if keep_reference 174 Sequel::Database.run_after_initialize(self) 175 176 initialize_load_extensions(:preconnect_extensions) 177 178 if before_preconnect = @opts[:before_preconnect] 179 before_preconnect.call(self) 180 end 181 182 if typecast_value_boolean(@opts[:preconnect]) && @pool.respond_to?(:preconnect, true) 183 concurrent = typecast_value_string(@opts[:preconnect]) == "concurrently" 184 @pool.send(:preconnect, concurrent) 185 end 186 187 initialize_load_extensions(:extensions) 188 test_connection if typecast_value_boolean(@opts.fetch(:test, true)) && respond_to?(:connect, true) 189 rescue 190 Sequel.synchronize{::Sequel::DATABASES.delete(self)} if keep_reference 191 raise 192 end 193 end
Register an extension callback for Database
objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.
# File lib/sequel/database/misc.rb 55 def self.register_extension(ext, mod=nil, &block) 56 if mod 57 raise(Error, "cannot provide both mod and block to Database.register_extension") if block 58 if mod.is_a?(Module) 59 block = proc{|db| db.extend(mod)} 60 else 61 block = mod 62 end 63 end 64 Sequel.synchronize{EXTENSIONS[ext] = block} 65 end
Run the after_initialize
hook for the given instance
.
# File lib/sequel/database/misc.rb 68 def self.run_after_initialize(instance) 69 @initialize_hook.call(instance) 70 end
Private Class Methods
Converts a uri to an options hash. These options are then passed to a newly created database object.
# File lib/sequel/database/misc.rb 74 def self.uri_to_options(uri) 75 { 76 :user => uri.user, 77 :password => uri.password, 78 :port => uri.port, 79 :host => uri.hostname, 80 :database => (m = /\/(.*)/.match(uri.path)) && (m[1]) 81 } 82 end
Public Instance Methods
Cast the given type to a literal type
DB.cast_type_literal(Float) # double precision DB.cast_type_literal(:foo) # foo
# File lib/sequel/database/misc.rb 222 def cast_type_literal(type) 223 type_literal(:type=>type) 224 end
Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database
objects, an Error will be raised. Returns self.
# File lib/sequel/database/misc.rb 231 def extension(*exts) 232 Sequel.extension(*exts) 233 exts.each do |ext| 234 if pr = Sequel.synchronize{EXTENSIONS[ext]} 235 if Sequel.synchronize{@loaded_extensions.include?(ext) ? false : (@loaded_extensions << ext)} 236 pr.call(self) 237 end 238 else 239 raise(Error, "Extension #{ext} does not have specific support handling individual databases (try: Sequel.extension #{ext.inspect})") 240 end 241 end 242 self 243 end
Freeze internal data structures for the Database
instance.
# File lib/sequel/database/misc.rb 196 def freeze 197 valid_connection_sql 198 metadata_dataset 199 @opts.freeze 200 @loggers.freeze 201 @pool.freeze 202 @dataset_class.freeze 203 @dataset_modules.freeze 204 @schema_type_classes.freeze 205 @loaded_extensions.freeze 206 metadata_dataset 207 super 208 end
Convert the given timestamp from the application's timezone, to the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 248 def from_application_timestamp(v) 249 Sequel.convert_output_timestamp(v, timezone) 250 end
Returns a string representation of the database object including the class name and connection URI and options used when connecting (if any).
# File lib/sequel/database/misc.rb 254 def inspect 255 a = [] 256 a << uri.inspect if uri 257 if (oo = opts[:orig_opts]) && !oo.empty? 258 a << oo.inspect 259 end 260 "#<#{self.class}: #{a.join(' ')}>" 261 end
Proxy the literal call to the dataset.
DB.literal(1) # 1 DB.literal(:a) # a DB.literal('a') # 'a'
# File lib/sequel/database/misc.rb 268 def literal(v) 269 schema_utility_dataset.literal(v) 270 end
Return the literalized version of the symbol if cached, or nil if it is not cached.
# File lib/sequel/database/misc.rb 274 def literal_symbol(sym) 275 Sequel.synchronize{@symbol_literal_cache[sym]} 276 end
Set the cached value of the literal symbol.
# File lib/sequel/database/misc.rb 279 def literal_symbol_set(sym, lit) 280 Sequel.synchronize{@symbol_literal_cache[sym] = lit} 281 end
Synchronize access to the prepared statements cache.
# File lib/sequel/database/misc.rb 284 def prepared_statement(name) 285 Sequel.synchronize{prepared_statements[name]} 286 end
Proxy the quote_identifier
method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
# File lib/sequel/database/misc.rb 291 def quote_identifier(v) 292 schema_utility_dataset.quote_identifier(v) 293 end
Return ruby class or array of classes for the given type symbol.
# File lib/sequel/database/misc.rb 296 def schema_type_class(type) 297 @schema_type_classes[type] 298 end
Default serial primary key options, used by the table creation code.
# File lib/sequel/database/misc.rb 301 def serial_primary_key_options 302 {:primary_key => true, :type => Integer, :auto_increment => true} 303 end
Cache the prepared statement object at the given name.
# File lib/sequel/database/misc.rb 306 def set_prepared_statement(name, ps) 307 Sequel.synchronize{prepared_statements[name] = ps} 308 end
Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.
# File lib/sequel/database/misc.rb 312 def sharded? 313 @sharded 314 end
The timezone to use for this database, defaulting to Sequel.database_timezone
.
# File lib/sequel/database/misc.rb 317 def timezone 318 @timezone || Sequel.database_timezone 319 end
Convert the given timestamp to the application's timezone, from the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 324 def to_application_timestamp(v) 325 Sequel.convert_timestamp(v, timezone) 326 end
Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.
# File lib/sequel/database/misc.rb 333 def typecast_value(column_type, value) 334 return nil if value.nil? 335 meth = "typecast_value_#{column_type}" 336 begin 337 # Allow calling private methods as per-type typecasting methods are private 338 respond_to?(meth, true) ? send(meth, value) : value 339 rescue ArgumentError, TypeError => e 340 raise Sequel.convert_exception_class(e, InvalidValue) 341 end 342 end
Returns the URI use to connect to the database. If a URI was not used when connecting, returns nil.
# File lib/sequel/database/misc.rb 346 def uri 347 opts[:uri] 348 end
Explicit alias of uri for easier subclassing.
# File lib/sequel/database/misc.rb 351 def url 352 uri 353 end
Private Instance Methods
:nocov:
# File lib/sequel/database/misc.rb 547 def _typecast_value_string_to_decimal(value) 548 d = BigDecimal(value) 549 if d.zero? 550 # BigDecimal parsing is loose by default, returning a 0 value for 551 # invalid input. If a zero value is received, use Float to check 552 # for validity. 553 begin 554 Float(value) 555 rescue ArgumentError 556 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 557 end 558 end 559 d 560 end
Per adapter initialization method, empty by default.
# File lib/sequel/database/misc.rb 358 def adapter_initialize 359 end
Returns true when the object is considered blank. The only objects that are blank are nil, false, strings with all whitespace, and ones that respond true to empty?
# File lib/sequel/database/misc.rb 365 def blank_object?(obj) 366 return obj.blank? if obj.respond_to?(:blank?) 367 case obj 368 when NilClass, FalseClass 369 true 370 when Numeric, TrueClass 371 false 372 when String 373 obj.strip.empty? 374 else 375 obj.respond_to?(:empty?) ? obj.empty? : false 376 end 377 end
Return the Sequel::DatabaseError
subclass to wrap the given exception in.
# File lib/sequel/database/misc.rb 388 def database_error_class(exception, opts) 389 database_specific_error_class(exception, opts) || DatabaseError 390 end
An enumerable yielding pairs of regexps and exception classes, used to match against underlying driver exception messages in order to raise a more specific Sequel::DatabaseError
subclass.
# File lib/sequel/database/misc.rb 382 def database_error_regexps 383 DEFAULT_DATABASE_ERROR_REGEXPS 384 end
Return the SQLState for the given exception, if one can be determined
# File lib/sequel/database/misc.rb 393 def database_exception_sqlstate(exception, opts) 394 nil 395 end
Return a specific Sequel::DatabaseError
exception class if one is appropriate for the underlying exception, or nil if there is no specific exception class.
# File lib/sequel/database/misc.rb 400 def database_specific_error_class(exception, opts) 401 return DatabaseDisconnectError if disconnect_error?(exception, opts) 402 403 if sqlstate = database_exception_sqlstate(exception, opts) 404 if klass = database_specific_error_class_from_sqlstate(sqlstate) 405 return klass 406 end 407 else 408 database_error_regexps.each do |regexp, klss| 409 return klss if exception.message =~ regexp 410 end 411 end 412 413 nil 414 end
Given the SQLState, return the appropriate DatabaseError subclass.
# File lib/sequel/database/misc.rb 422 def database_specific_error_class_from_sqlstate(sqlstate) 423 case sqlstate 424 when *NOT_NULL_CONSTRAINT_SQLSTATES 425 NotNullConstraintViolation 426 when *FOREIGN_KEY_CONSTRAINT_SQLSTATES 427 ForeignKeyConstraintViolation 428 when *UNIQUE_CONSTRAINT_SQLSTATES 429 UniqueConstraintViolation 430 when *CHECK_CONSTRAINT_SQLSTATES 431 CheckConstraintViolation 432 when *SERIALIZATION_CONSTRAINT_SQLSTATES 433 SerializationFailure 434 end 435 end
Return true if exception represents a disconnect error, false otherwise.
# File lib/sequel/database/misc.rb 438 def disconnect_error?(exception, opts) 439 opts[:disconnect] 440 end
Load extensions during initialization from the given key in opts.
# File lib/sequel/database/misc.rb 443 def initialize_load_extensions(key) 444 case exts = @opts[key] 445 when String 446 extension(*exts.split(',').map(&:to_sym)) 447 when Array 448 extension(*exts) 449 when Symbol 450 extension(exts) 451 when nil 452 # nothing 453 else 454 raise Error, "unsupported Database #{key.inspect} option: #{@opts[key].inspect}" 455 end 456 end
Convert the given exception to an appropriate Sequel::DatabaseError
subclass, keeping message and backtrace.
# File lib/sequel/database/misc.rb 460 def raise_error(exception, opts=OPTS) 461 if !opts[:classes] || Array(opts[:classes]).any?{|c| exception.is_a?(c)} 462 raise Sequel.convert_exception_class(exception, database_error_class(exception, opts)) 463 else 464 raise exception 465 end 466 end
Swallow database errors, unless they are connect/disconnect errors.
# File lib/sequel/database/misc.rb 469 def swallow_database_error 470 yield 471 rescue Sequel::DatabaseDisconnectError, DatabaseConnectionError 472 # Always raise disconnect errors 473 raise 474 rescue Sequel::DatabaseError 475 # Don't raise other database errors. 476 nil 477 # else 478 # Don't rescue other exceptions, they will be raised normally. 479 end
Check the bytesize of the string value, if value is a string.
# File lib/sequel/database/misc.rb 491 def typecast_check_length(value, max_size) 492 typecast_check_string_length(value, max_size) if String === value 493 value 494 end
Check the bytesize of a string before conversion. There is no point trying to typecast strings that would be way too long.
# File lib/sequel/database/misc.rb 483 def typecast_check_string_length(string, max_size) 484 if @check_string_typecast_bytesize && string.bytesize > max_size 485 raise InvalidValue, "string too long to typecast (bytesize: #{string.bytesize}, max: #{max_size})" 486 end 487 string 488 end
Typecast the value to an SQL::Blob
# File lib/sequel/database/misc.rb 497 def typecast_value_blob(value) 498 value.is_a?(Sequel::SQL::Blob) ? value : Sequel::SQL::Blob.new(value) 499 end
Typecast the value to true, false, or nil
# File lib/sequel/database/misc.rb 502 def typecast_value_boolean(value) 503 case value 504 when false, 0, "0", /\Af(alse)?\z/i, /\Ano?\z/i 505 false 506 else 507 blank_object?(value) ? nil : true 508 end 509 end
Typecast the value to a Date
# File lib/sequel/database/misc.rb 512 def typecast_value_date(value) 513 case value 514 when DateTime, Time 515 Date.new(value.year, value.month, value.day) 516 when Date 517 value 518 when String 519 Sequel.string_to_date(typecast_check_string_length(value, 100)) 520 when Hash 521 Date.new(*[:year, :month, :day].map{|x| typecast_check_length(value[x] || value[x.to_s], 100).to_i}) 522 else 523 raise InvalidValue, "invalid value for Date: #{value.inspect}" 524 end 525 end
Typecast the value to a DateTime or Time depending on Sequel.datetime_class
# File lib/sequel/database/misc.rb 528 def typecast_value_datetime(value) 529 case value 530 when String 531 Sequel.typecast_to_application_timestamp(typecast_check_string_length(value, 100)) 532 when Hash 533 [:year, :month, :day, :hour, :minute, :second, :nanos, :offset].each do |x| 534 typecast_check_length(value[x] || value[x.to_s], 100) 535 end 536 Sequel.typecast_to_application_timestamp(value) 537 else 538 Sequel.typecast_to_application_timestamp(value) 539 end 540 end
Typecast the value to a BigDecimal
# File lib/sequel/database/misc.rb 565 def typecast_value_decimal(value) 566 case value 567 when BigDecimal 568 value 569 when Numeric 570 BigDecimal(value.to_s) 571 when String 572 _typecast_value_string_to_decimal(typecast_check_string_length(value, 1000)) 573 else 574 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 575 end 576 end
Typecast the value to a Float
# File lib/sequel/database/misc.rb 579 def typecast_value_float(value) 580 Float(typecast_check_length(value, 1000)) 581 end
Typecast the value to an Integer
# File lib/sequel/database/misc.rb 584 def typecast_value_integer(value) 585 case value 586 when String 587 typecast_check_string_length(value, 100) 588 if value =~ /\A-?0+(\d)/ 589 Integer(value, 10) 590 else 591 Integer(value) 592 end 593 else 594 Integer(value) 595 end 596 end
Typecast the value to a String
# File lib/sequel/database/misc.rb 599 def typecast_value_string(value) 600 case value 601 when Hash, Array 602 raise Sequel::InvalidValue, "invalid value for String: #{value.inspect}" 603 else 604 value.to_s 605 end 606 end
Typecast the value to a Time
# File lib/sequel/database/misc.rb 609 def typecast_value_time(value) 610 case value 611 when Time 612 if value.is_a?(SQLTime) 613 value 614 else 615 SQLTime.create(value.hour, value.min, value.sec, value.nsec/1000.0) 616 end 617 when String 618 Sequel.string_to_time(typecast_check_string_length(value, 100)) 619 when Hash 620 SQLTime.create(*[:hour, :minute, :second].map{|x| typecast_check_length(value[x] || value[x.to_s], 100).to_i}) 621 else 622 raise Sequel::InvalidValue, "invalid value for Time: #{value.inspect}" 623 end 624 end
9 - Methods that describe what the database supports
↑ topPublic Instance Methods
Whether the database uses a global namespace for the index, true by default. If false, the indexes are going to be namespaced per table.
# File lib/sequel/database/features.rb 13 def global_index_namespace? 14 true 15 end
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 19 def supports_create_table_if_not_exists? 20 false 21 end
Whether the database supports deferrable constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 25 def supports_deferrable_constraints? 26 false 27 end
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 31 def supports_deferrable_foreign_key_constraints? 32 supports_deferrable_constraints? 33 end
Whether the database supports DROP TABLE IF EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 37 def supports_drop_table_if_exists? 38 supports_create_table_if_not_exists? 39 end
Whether the database supports Database#foreign_key_list for parsing foreign keys.
# File lib/sequel/database/features.rb 43 def supports_foreign_key_parsing? 44 respond_to?(:foreign_key_list) 45 end
Whether the database supports Database#indexes for parsing indexes.
# File lib/sequel/database/features.rb 48 def supports_index_parsing? 49 respond_to?(:indexes) 50 end
Whether the database supports partial indexes (indexes on a subset of a table), false by default.
# File lib/sequel/database/features.rb 54 def supports_partial_indexes? 55 false 56 end
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 60 def supports_prepared_transactions? 61 false 62 end
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/features.rb 65 def supports_savepoints? 66 false 67 end
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 71 def supports_savepoints_in_prepared_transactions? 72 supports_prepared_transactions? && supports_savepoints? 73 end
Whether the database supports schema parsing via Database#schema
.
# File lib/sequel/database/features.rb 76 def supports_schema_parsing? 77 respond_to?(:schema_parse_table, true) 78 end
Whether the database supports Database#tables for getting list of tables.
# File lib/sequel/database/features.rb 81 def supports_table_listing? 82 respond_to?(:tables) 83 end
Whether the database and adapter support transaction isolation levels, false by default.
# File lib/sequel/database/features.rb 91 def supports_transaction_isolation_levels? 92 false 93 end
Whether DDL statements work correctly in transactions, false by default.
# File lib/sequel/database/features.rb 96 def supports_transactional_ddl? 97 false 98 end
Whether the database supports Database#views for getting list of views.
# File lib/sequel/database/features.rb 86 def supports_view_listing? 87 respond_to?(:views) 88 end
Whether CREATE VIEW … WITH CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 101 def supports_views_with_check_option? 102 !!view_with_check_option_support 103 end
Whether CREATE VIEW … WITH LOCAL CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 106 def supports_views_with_local_check_option? 107 view_with_check_option_support == :local 108 end
Private Instance Methods
Whether the database supports adding primary key constraints on NULLable columns, automatically making them NOT NULL. If false, the columns must be set NOT NULL before the primary key constraint is added.
# File lib/sequel/database/features.rb 115 def can_add_primary_key_constraint_on_nullable_columns? 116 true 117 end
Whether this dataset considers unquoted identifiers as uppercase. True by default as that is the SQL standard
# File lib/sequel/database/features.rb 121 def folds_unquoted_identifiers_to_uppercase? 122 true 123 end
Whether the database supports combining multiple alter table operations into a single query, false by default.
# File lib/sequel/database/features.rb 127 def supports_combining_alter_table_ops? 128 false 129 end
Whether the database supports CREATE OR REPLACE VIEW. If not, support will be emulated by dropping the view first. false by default.
# File lib/sequel/database/features.rb 133 def supports_create_or_replace_view? 134 false 135 end
Whether the database supports named column constraints. True by default. Those that don't support named column constraints have to have column constraints converted to table constraints if the column constraints have names.
# File lib/sequel/database/features.rb 141 def supports_named_column_constraints? 142 true 143 end
Don't advertise support for WITH CHECK OPTION by default.
# File lib/sequel/database/features.rb 146 def view_with_check_option_support 147 nil 148 end