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
  3. inherited

Public Instance

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

Attributes

comparison_attrs [R]

All attributes used for equality and hash methods.

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 76
def attr_reader(*args)
  super
  comparison_attrs.concat(args)
end
inherited (subclass)

Copy the ::comparison_attrs into the subclass.

[show source] 
# File lib/sequel/sql.rb, line 82
def inherited(subclass)
  super
  subclass.instance_variable_set(:@comparison_attrs, comparison_attrs.dup)
end

Public Instance methods

== (other)

Alias of eql?

[show source] 
# File lib/sequel/sql.rb, line 101
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 107
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 112
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 118
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 123
def lit
  self
end
sql_literal (ds)

Alias of to_s

[show source] 
# File lib/sequel/sql.rb, line 128
def sql_literal(ds)
  s = ''
  to_s_append(ds, s)
  s
end