module Rein::Constraint::Exclusion

This module contains methods for defining exclusion constraints.

Public Instance Methods

add_exclusion_constraint(*args) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 9
def add_exclusion_constraint(*args)
  reversible do |dir|
    dir.up { _add_exclusion_constraint_adapter(*args) }
    dir.down { _remove_exclusion_constraint_adapter(*args) }
  end
end
remove_exclusion_constraint(*args) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 16
def remove_exclusion_constraint(*args)
  reversible do |dir|
    dir.up { _remove_exclusion_constraint_adapter(*args) }
    dir.down { _add_exclusion_constraint_adapter(*args) }
  end
end

Private Instance Methods

_add_exclusion_constraint(table, attributes, options = {}) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 41
def _add_exclusion_constraint(table, attributes, options = {})
  name = Util.constraint_name(table, attributes.map { |att| att[0] }.join('_'), 'exclude', options)
  table = Util.wrap_identifier(table)
  attributes = attributes.map do |attribute|
    _get_attribute_expression(attribute)
  end
  initially = options[:deferred] ? 'DEFERRED' : 'IMMEDIATE'
  using = options[:using] ? " USING #{options[:using]}" : ''
  sql = "ALTER TABLE #{table} ADD CONSTRAINT #{name} EXCLUDE#{using} (#{attributes.join(', ')})"
  sql << " WHERE (#{options[:where]})" if options[:where].present?
  sql << " DEFERRABLE INITIALLY #{initially}" unless options[:deferrable] == false
  execute(sql)
end
_add_exclusion_constraint_adapter(*args) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 25
def _add_exclusion_constraint_adapter(*args)
  if args[1].is_a? Array
    _add_exclusion_constraint(*args)
  else
    _add_exclusion_constraint(args[0], [[args[1], args[2]]], args[3] || {})
  end
end
_get_attribute_expression(attribute) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 55
def _get_attribute_expression(attribute)
  if attribute.size > 2
    "#{Util.wrap_identifier(attribute[0])} #{attribute[1, attribute.size - 2].join(' ')} WITH #{attribute.last}"
  else
    "#{Util.wrap_identifier(attribute[0])} WITH #{attribute[1]}"
  end
end
_remove_exclusion_constraint(table, attributes, options = {}) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 63
def _remove_exclusion_constraint(table, attributes, options = {})
  name = Util.constraint_name(table, attributes.map { |att| att[0] }.join('_'), 'exclude', options)
  table = Util.wrap_identifier(table)
  execute("ALTER TABLE #{table} DROP CONSTRAINT #{name}")
end
_remove_exclusion_constraint_adapter(*args) click to toggle source
# File lib/rein/constraint/exclusion.rb, line 33
def _remove_exclusion_constraint_adapter(*args)
  if args[1].is_a? Array
    _remove_exclusion_constraint(*args)
  else
    _remove_exclusion_constraint(args[0], [[args[1], args[2]]], args[3] || {})
  end
end