Class Sequel::SQL::ComplexExpression
In: lib/sequel/sql.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 the blockless filter support in Sequel.

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

new  

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
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', \ :~, :'!~', :'~*', :'!~*', :IN, :'NOT IN', :ILIKE, :'NOT ILIKE'] + \ INEQUALITY_OPERATORS + BITWISE_OPERATORS + IS_OPERATORS   Operator symbols that take exactly two arguments
N_ARITY_OPERATORS = [:AND, :OR, :'||'] + MATHEMATICAL_OPERATORS   Operator symbols that take one or more arguments
ONE_ARITY_OPERATORS = [:NOT, :NOOP, :'B~']   Operator symbols that take one argument

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 with all two pairs to BooleanExpressions. 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 153
153:       def initialize(op, *args)
154:         args.map!{|a| Sequel.condition_specifier?(a) ? SQL::BooleanExpression.from_value_pairs(a) : a}
155:         case op
156:         when *N_ARITY_OPERATORS
157:           raise(Error, "The #{op} operator requires at least 1 argument") unless args.length >= 1
158:           old_args = args
159:           args = []
160:           old_args.each{|a| a.is_a?(self.class) && a.op == op ? args.concat(a.args) : args.push(a)}
161:         when *TWO_ARITY_OPERATORS
162:           raise(Error, "The #{op} operator requires precisely 2 arguments") unless args.length == 2
163:         when *ONE_ARITY_OPERATORS
164:           raise(Error, "The #{op} operator requires a single argument") unless args.length == 1
165:         else
166:           raise(Error, "Invalid operator #{op}")
167:         end
168:         @op = op
169:         @args = args
170:       end

[Validate]