Class Sequel::SQL::ComplexExpression
In: lib/sequel/sql.rb
lib/sequel/extensions/eval_inspect.rb
Parent: Expression

Represents a complex 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.

Methods

Included Modules

AliasMethods CastMethods OrderMethods SubscriptMethods

Constants

OPERTATOR_INVERSIONS = {:AND => :OR, :OR => :AND, :< => :>=, :> => :<=, :<= => :>, :>= => :<, :'=' => :'!=' , :'!=' => :'=', :LIKE => :'NOT LIKE', :'NOT LIKE' => :LIKE, :~ => :'!~', :'!~' => :~, :IN => :'NOT IN', :'NOT IN' => :IN, :IS => :'IS NOT', :'IS NOT' => :IS, :'~*' => :'!~*', :'!~*' => :'~*', :NOT => :NOOP, :NOOP => :NOT, :ILIKE => :'NOT ILIKE', :'NOT ILIKE'=>:ILIKE}   A hash of the opposite for each operator symbol, used for inverting objects.
MATHEMATICAL_OPERATORS = [:+, :-, :/, :*]   Standard mathematical operators used in NumericMethods
BITWISE_OPERATORS = [:&, :|, :^, :<<, :>>, :%]   Bitwise mathematical operators used in NumericMethods
INEQUALITY_OPERATORS = [:<, :>, :<=, :>=]   Inequality operators used in InequalityMethods
BOOLEAN_OPERATOR_METHODS = {:& => :AND, :| =>:OR}   Hash of ruby operator symbols to SQL operators, used in BooleanMethods
IN_OPERATORS = [:IN, :'NOT IN']   Operators that use IN/NOT IN for inclusion/exclusion
IS_OPERATORS = [:IS, :'IS NOT']   Operators that use IS, used for special casing to override literal true/false values
TWO_ARITY_OPERATORS = [:'=', :'!=', :LIKE, :'NOT LIKE', \ :~, :'!~', :'~*', :'!~*', :ILIKE, :'NOT ILIKE'] + \ INEQUALITY_OPERATORS + IS_OPERATORS + IN_OPERATORS   Operator symbols that take exactly two arguments
N_ARITY_OPERATORS = [:AND, :OR, :'||'] + MATHEMATICAL_OPERATORS + BITWISE_OPERATORS   Operator symbols that take one or more arguments
ONE_ARITY_OPERATORS = [:NOT, :NOOP, :'B~']   Operator symbols that take only a single argument
CUSTOM_EXPRESSIONS = [:extract]   Custom expressions that may have different syntax on different databases
CONSTANT_INVERSIONS = {Constants::TRUE=>Constants::FALSE, Constants::FALSE=>Constants::TRUE, Constants::NULL=>Constants::NOTNULL, Constants::NOTNULL=>Constants::NULL}   A hash of the opposite for each constant, used for inverting constants.

Attributes

args  [R]  An array of args for this object
op  [R]  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.

[Source]

     # File lib/sequel/sql.rb, line 180
180:       def initialize(op, *args)
181:         orig_args = args
182:         args = args.map{|a| Sequel.condition_specifier?(a) ? SQL::BooleanExpression.from_value_pairs(a) : a}
183:         case op
184:         when *N_ARITY_OPERATORS
185:           raise(Error, "The #{op} operator requires at least 1 argument") unless args.length >= 1
186:           old_args = args
187:           args = []
188:           old_args.each{|a| a.is_a?(self.class) && a.op == op ? args.concat(a.args) : args.push(a)}
189:         when *TWO_ARITY_OPERATORS
190:           raise(Error, "The #{op} operator requires precisely 2 arguments") unless args.length == 2
191:           # With IN/NOT IN, even if the second argument is an array of two element arrays,
192:           # don't convert it into a boolean expression, since it's definitely being used
193:           # as a value list.
194:           args[1] = orig_args[1] if IN_OPERATORS.include?(op)
195:         when *ONE_ARITY_OPERATORS
196:           raise(Error, "The #{op} operator requires a single argument") unless args.length == 1
197:         when *CUSTOM_EXPRESSIONS
198:           # nothing
199:         else
200:           raise(Error, "Invalid operator #{op}")
201:         end
202:         @op = op
203:         @args = args
204:       end

Public Instance methods

Return a BooleanExpression with the same op and args.

[Source]

      # File lib/sequel/sql.rb, line 1042
1042:       def sql_boolean
1043:         BooleanExpression.new(self.op, *self.args)
1044:       end

Return a NumericExpression with the same op and args.

[Source]

      # File lib/sequel/sql.rb, line 1047
1047:       def sql_number
1048:         NumericExpression.new(self.op, *self.args)
1049:       end

Return a StringExpression with the same op and args.

[Source]

      # File lib/sequel/sql.rb, line 1052
1052:       def sql_string
1053:         StringExpression.new(self.op, *self.args)
1054:       end

[Validate]