class Sequel::SQL::ComplexExpression
Represents a SQL
expression, with a given operator and one or more attributes (which may also be ComplexExpressions, forming a tree). This class is the backbone of Sequel's ruby expression DSL.
This is an abstract class that is not that useful by itself. The subclasses BooleanExpression
, NumericExpression
, and StringExpression
define the behavior of the DSL via operators.
Constants
- ASSOCIATIVE_OPERATORS
Operator symbols that are associative
- BITWISE_OPERATORS
Bitwise mathematical operators used in
BitwiseMethods
- BOOLEAN_OPERATOR_METHODS
Hash
of ruby operator symbols toSQL
operators, used inBooleanMethods
- CONSTANT_INVERSIONS
A hash of the opposite for each constant, used for inverting constants.
- CUSTOM_EXPRESSIONS
Custom expressions that may have different syntax on different databases
- EQUALITY_OPERATORS
Operators that check for equality
- INEQUALITY_OPERATORS
Inequality operators used in
InequalityMethods
- IN_OPERATORS
Operators that use IN/NOT IN for inclusion/exclusion
- IS_OPERATORS
Operators that use IS, used for special casing to override literal true/false values
- LIKE_OPERATORS
Operators that do pattern matching via LIKE
- MATHEMATICAL_OPERATORS
Standard mathematical operators used in
NumericMethods
- N_ARITY_OPERATORS
Operator symbols that take one or more arguments
- ONE_ARITY_OPERATORS
Operator symbols that take only a single argument
- OPERATOR_INVERSIONS
A hash of the opposite for each operator symbol, used for inverting objects.
- OPERTATOR_INVERSIONS
SEQUEL6: Remove
- REGEXP_OPERATORS
Operators that do pattern matching via regular expressions
- TWO_ARITY_OPERATORS
Operator symbols that take exactly two arguments
Attributes
An array of args for this object
The operator symbol for this object
Public Class Methods
Set the operator symbol and arguments for this object to the ones given. Convert all args that are hashes or arrays of two element arrays to BooleanExpressions
, other than the second arg for an IN/NOT IN operator. Raise an Error
if the operator doesn't allow boolean input and a boolean argument is given. Raise an Error
if the wrong number of arguments for a given operator is used.
# File lib/sequel/sql.rb 219 def initialize(op, *args) 220 orig_args = args 221 args = args.map{|a| Sequel.condition_specifier?(a) ? SQL::BooleanExpression.from_value_pairs(a) : a} 222 case op 223 when *N_ARITY_OPERATORS 224 raise(Error, "The #{op} operator requires at least 1 argument") unless args.length >= 1 225 args.map!{|a| a.is_a?(self.class) && a.op == :NOOP ? a.args.first : a} 226 if ASSOCIATIVE_OPERATORS.include?(op) 227 old_args = args 228 args = [] 229 old_args.each{|a| a.is_a?(self.class) && a.op == op ? args.concat(a.args) : args.push(a)} 230 end 231 when *TWO_ARITY_OPERATORS 232 raise(Error, "The #{op} operator requires precisely 2 arguments") unless args.length == 2 233 # With IN/NOT IN, even if the second argument is an array of two element arrays, 234 # don't convert it into a boolean expression, since it's definitely being used 235 # as a value list. 236 args[1] = orig_args[1] if IN_OPERATORS.include?(op) 237 when *ONE_ARITY_OPERATORS 238 raise(Error, "The #{op} operator requires a single argument") unless args.length == 1 239 when *CUSTOM_EXPRESSIONS 240 # nothing 241 else 242 raise(Error, "Invalid operator #{op}") 243 end 244 @op = op 245 @args = args.freeze 246 freeze 247 end
Public Instance Methods
Return a BooleanExpression
with the same op and args.
# File lib/sequel/sql.rb 1281 def sql_boolean 1282 BooleanExpression.new(op, *args) 1283 end
Return a NumericExpression
with the same op and args.
# File lib/sequel/sql.rb 1286 def sql_number 1287 NumericExpression.new(op, *args) 1288 end
Return a StringExpression
with the same op and args.
# File lib/sequel/sql.rb 1291 def sql_string 1292 StringExpression.new(op, *args) 1293 end
Private Instance Methods
ComplexExpression's initializer uses a splat for the operator arguments.
# File lib/sequel/extensions/eval_inspect.rb 99 def inspect_args 100 [:op, "*args"] 101 end