# File lib/active_record/relation.rb, line 316 def primary_key @primary_key ||= table[@klass.primary_key] end
# File lib/active_record/relation.rb, line 349 def ==(other) case other when Relation other.to_sql == to_sql when Array to_a == other.to_a end end
# File lib/active_record/relation.rb, line 96 def any? if block_given? to_a.any? { |*block_args| yield(*block_args) } else !empty? end end
# File lib/active_record/relation.rb, line 41 def create(*args, &block) scoping { @klass.create(*args, &block) } end
# File lib/active_record/relation.rb, line 45 def create!(*args, &block) scoping { @klass.create!(*args, &block) } end
Deletes the row with a primary key matching the id
argument,
using a SQL DELETE
statement, and returns the number of rows
deleted. Active Record objects are not instantiated, so the object’s
callbacks are not executed, including any :dependent
association options or Observer methods.
You can delete multiple rows at once by passing an Array of
id
s.
Note: Although it is often much faster than the alternative,
#destroy
, skipping callbacks might bypass business logic in
your application that ensures referential integrity or performs other
essential jobs.
# Delete a single row Todo.delete(1) # Delete multiple rows Todo.delete([2,3,4])
# File lib/active_record/relation.rb, line 299 def delete(id_or_array) where(@klass.primary_key => id_or_array).delete_all end
Deletes the records matching conditions
without instantiating
the records first, and hence not calling the destroy
method
nor invoking callbacks. This is a single SQL DELETE statement that goes
straight to the database, much more efficient than
destroy_all
. Be careful with relations though, in particular
:dependent
rules defined on associations are not honored.
Returns the number of rows affected.
conditions
- Conditions are specified the same way as with
find
method.
Post.delete_all("person_id = 5 AND (category = 'Something' OR category = 'Else')") Post.delete_all(["person_id = ? AND (category = ? OR category = ?)", 5, 'Something', 'Else'])
Both calls delete the affected posts all at once with a single DELETE
statement. If you need to destroy dependent associations or call your
before_*
or after_destroy
callbacks, use the
destroy_all
method instead.
# File lib/active_record/relation.rb, line 275 def delete_all(conditions = nil) conditions ? where(conditions).delete_all : arel.delete.tap { reset } end
Destroy an object (or multiple objects) that has the given id, the object is instantiated first, therefore all callbacks and filters are fired off before the object is deleted. This method is less efficient than ActiveRecord#delete but allows cleanup methods and other actions to be run.
This essentially finds the object (or multiple objects) with the given id, creates a new object from the attributes, and then calls destroy on it.
id
- Can be either an Integer or an Array of Integers.
# Destroy a single object Todo.destroy(1) # Destroy multiple objects todos = [1,2,3] Todo.destroy(todos)
# File lib/active_record/relation.rb, line 249 def destroy(id) if id.is_a?(Array) id.map { |one_id| destroy(one_id) } else find(id).destroy end end
Destroys the records matching conditions
by instantiating each
record and calling its destroy
method. Each object’s
callbacks are executed (including :dependent
association
options and before_destroy
/after_destroy
Observer methods). Returns the collection of
objects that were destroyed; each will be frozen, to reflect that no
changes should be made (since they can’t be persisted).
Note: Instantiation, callback execution, and deletion of each record can be
time consuming when you’re removing many records at once. It generates at
least one SQL DELETE
query per record (or possibly more, to
enforce your callbacks). If you want to delete many rows quickly, without
concern for their associations or callbacks, use delete_all
instead.
conditions
- A string, array, or hash that specifies which
records to destroy. If omitted, all records are destroyed. See the
Conditions section in the introduction to ActiveRecord::Base for more information.
Person.destroy_all("last_login < '2004-04-04'") Person.destroy_all(:status => "inactive")
# File lib/active_record/relation.rb, line 222 def destroy_all(conditions = nil) if conditions where(conditions).destroy_all else to_a.each {|object| object.destroy }.tap { reset } end end
# File lib/active_record/relation.rb, line 345 def eager_loading? @should_eager_load ||= (@eager_load_values.any? || (@includes_values.any? && references_eager_loaded_tables?)) end
Returns true if there are no records.
# File lib/active_record/relation.rb, line 89 def empty? return @records.empty? if loaded? c = count c.respond_to?(:zero?) ? c.zero? : c.empty? end
# File lib/active_record/relation.rb, line 35 def initialize_copy(other) reset end
# File lib/active_record/relation.rb, line 358 def inspect to_a.inspect end
# File lib/active_record/relation.rb, line 104 def many? if block_given? to_a.many? { |*block_args| yield(*block_args) } else @limit_value ? to_a.many? : size > 1 end end
# File lib/active_record/relation.rb, line 31 def new(*args, &block) scoping { @klass.new(*args, &block) } end
# File lib/active_record/relation.rb, line 316 def primary_key @primary_key ||= table[@klass.primary_key] end
# File lib/active_record/relation.rb, line 303 def reload reset to_a # force reload self end
# File lib/active_record/relation.rb, line 309 def reset @first = @last = @to_sql = @order_clause = @scope_for_create = @arel = @loaded = nil @should_eager_load = @join_dependency = nil @records = [] self end
# File lib/active_record/relation.rb, line 49 def respond_to?(method, include_private = false) return true if arel.respond_to?(method, include_private) || Array.method_defined?(method) || @klass.respond_to?(method, include_private) if match = DynamicFinderMatch.match(method) return true if @klass.send(:all_attributes_exists?, match.attribute_names) elsif match = DynamicScopeMatch.match(method) return true if @klass.send(:all_attributes_exists?, match.attribute_names) else super end end
# File lib/active_record/relation.rb, line 335 def scope_for_create @scope_for_create ||= begin if @create_with_value @create_with_value.reverse_merge(where_values_hash) else where_values_hash end end end
Scope all queries to the current scope.
Comment.where(:post_id => 1).scoping do Comment.first # SELECT * FROM comments WHERE post_id = 1 end
Please check unscoped if you want to remove all previous scopes (including the default_scope) during the execution of a block.
# File lib/active_record/relation.rb, line 122 def scoping @klass.scoped_methods << self begin yield ensure @klass.scoped_methods.pop end end
Returns size of the records.
# File lib/active_record/relation.rb, line 84 def size loaded? ? @records.length : count end
# File lib/active_record/relation.rb, line 61 def to_a return @records if loaded? @records = eager_loading? ? find_with_associations : @klass.find_by_sql(arel.to_sql) preload = @preload_values preload += @includes_values unless eager_loading? preload.each {|associations| @klass.send(:preload_associations, @records, associations) } # @readonly_value is true only if set explicitly. @implicit_readonly is true if there # are JOINS and no explicit SELECT. readonly = @readonly_value.nil? ? @implicit_readonly : @readonly_value @records.each { |record| record.readonly! } if readonly @loaded = true @records end
# File lib/active_record/relation.rb, line 320 def to_sql @to_sql ||= arel.to_sql end
Updates an object (or multiple objects) and saves it to the database, if validations pass. The resulting object is returned whether the object was saved successfully to the database or not.
id
- This should be the id or an array of ids to be updated.
attributes
- This should be a hash of attributes or an array
of hashes.
# Updates one record Person.update(15, :user_name => 'Samuel', :group => 'expert') # Updates multiple records people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } } Person.update(people.keys, people.values)
# File lib/active_record/relation.rb, line 185 def update(id, attributes) if id.is_a?(Array) idx = -1 id.collect { |one_id| idx += 1; update(one_id, attributes[idx]) } else object = find(id) object.update_attributes(attributes) object end end
Updates all records with details given if they match a set of conditions supplied, limits and order can also be supplied. This method constructs a single SQL UPDATE statement and sends it straight to the database. It does not instantiate the involved models and it does not trigger Active Record callbacks or validations.
updates
- A string, array, or hash representing the SET part
of an SQL statement.
conditions
- A string, array, or hash representing the WHERE
part of an SQL statement. See conditions in the intro.
options
- Additional options are :limit
and
:order
, see the examples for usage.
# Update all customers with the given attributes Customer.update_all :wants_email => true # Update all books with 'Rails' in their title Book.update_all "author = 'David'", "title LIKE '%Rails%'" # Update all avatars migrated more than a week ago Avatar.update_all ['migrated_at = ?', Time.now.utc], ['migrated_at > ?', 1.week.ago] # Update all books that match conditions, but limit it to 5 ordered by date Book.update_all "author = 'David'", "title LIKE '%Rails%'", :order => 'created_at', :limit => 5
# File lib/active_record/relation.rb, line 156 def update_all(updates, conditions = nil, options = {}) if conditions || options.present? where(conditions).apply_finder_options(options.slice(:limit, :order)).update_all(updates) else # Apply limit and order only if they're both present if @limit_value.present? == @order_values.present? arel.update(Arel::SqlLiteral.new(@klass.send(:sanitize_sql_for_assignment, updates))) else except(:limit, :order).update_all(updates) end end end
# File lib/active_record/relation.rb, line 324 def where_values_hash Hash[@where_values.find_all { |w| w.respond_to?(:operator) && w.operator == :== && w.left.relation.name == table_name }.map { |where| [ where.left.name, where.right.respond_to?(:value) ? where.right.value : where.right ] }] end
# File lib/active_record/relation.rb, line 364 def method_missing(method, *args, &block) if Array.method_defined?(method) to_a.send(method, *args, &block) elsif @klass.scopes[method] merge(@klass.send(method, *args, &block)) elsif @klass.respond_to?(method) scoping { @klass.send(method, *args, &block) } elsif arel.respond_to?(method) arel.send(method, *args, &block) else super end end
# File lib/active_record/relation.rb, line 20 def initialize(klass, table) @klass, @table = klass, table @implicit_readonly = nil @loaded = false SINGLE_VALUE_METHODS.each {|v| instance_variable_set(:"@#{v}_value", nil)} (ASSOCIATION_METHODS + MULTI_VALUE_METHODS).each {|v| instance_variable_set(:"@#{v}_values", [])} @extensions = [] end