class Sequel::SQL::Expression

  1. lib/sequel/sql.rb
Parent: SQL

Base class for all SQL expression objects.

Methods

Public Class

  1. attr_reader
  2. comparison_attrs

Public Instance

  1. ==
  2. eql?
  3. hash
  4. inspect
  5. lit
  6. sql_literal

Public Class methods

attr_reader (*args)

Expression objects are assumed to be value objects, where their attribute values can't change after assignment. In order to make it easy to define equality and hash methods, subclass instances assume that the only values that affect the results of such methods are the values of the object's attributes.

[show source] 
# File lib/sequel/sql.rb, line 68
def self.attr_reader(*args)
  super
  comparison_attrs.concat args
end
comparison_attrs ()

All attributes used for equality and hash methods.

[show source] 
# File lib/sequel/sql.rb, line 74
def self.comparison_attrs
  @comparison_attrs ||= self == Expression ? [] : superclass.comparison_attrs.clone
end

Public Instance methods

== (other)

Alias of eql?

[show source] 
# File lib/sequel/sql.rb, line 88
def ==(other)
  eql?(other)
end
eql? (other)

Returns true if the receiver is the same expression as the the other expression.

[show source] 
# File lib/sequel/sql.rb, line 94
def eql?(other)
  other.is_a?(self.class) && !self.class.comparison_attrs.find{|a| send(a) != other.send(a)}
end
hash ()

Make sure that the hash value is the same if the attributes are the same.

[show source] 
# File lib/sequel/sql.rb, line 99
def hash
  ([self.class] + self.class.comparison_attrs.map{|x| send(x)}).hash
end
inspect ()

Show the class name and instance variables for the object, necessary for correct operation on ruby 1.9.2.

[show source] 
# File lib/sequel/sql.rb, line 105
def inspect
  "#<#{self.class} #{instance_variables.map{|iv| "#{iv}=>#{instance_variable_get(iv).inspect}"}.join(', ')}>"
end
lit ()

Returns self, because SQL::Expression already acts like LiteralString.

[show source] 
# File lib/sequel/sql.rb, line 110
def lit
  self
end
sql_literal (ds)

Alias of to_s

[show source] 
# File lib/sequel/sql.rb, line 115
def sql_literal(ds)
  to_s(ds)
end