From 752813016ed227ecfbe0bf69c92de2e2c3e7a988 Mon Sep 17 00:00:00 2001
From: Pratik Naik <pratiknaik@gmail.com>
Date: Fri, 1 Jan 2010 22:54:23 +0530
Subject: Add support for table aliasing
Example :
users = Table(:users, :as => :accounts)
users.to_sql
=> SELECT `accounts`.`id`, `accounts`.`name` FROM `users` AS `accounts`
---
lib/arel/engines/sql/christener.rb | 3 ++-
lib/arel/engines/sql/relations/table.rb | 18 +++++++++++++++---
2 files changed, 17 insertions(+), 4 deletions(-)
(limited to 'lib/arel/engines')
diff --git a/lib/arel/engines/sql/christener.rb b/lib/arel/engines/sql/christener.rb
index c1c9325208..a2a2da799a 100644
--- a/lib/arel/engines/sql/christener.rb
+++ b/lib/arel/engines/sql/christener.rb
@@ -4,7 +4,8 @@ module Arel
def name_for(relation)
@used_names ||= Hash.new(0)
(@relation_names ||= Hash.new do |hash, relation|
- @used_names[name = relation.name] += 1
+ name = relation.table_alias ? relation.table_alias : relation.name
+ @used_names[name] += 1
hash[relation] = name + (@used_names[name] > 1 ? "_#{@used_names[name]}" : '')
end)[relation.table]
end
diff --git a/lib/arel/engines/sql/relations/table.rb b/lib/arel/engines/sql/relations/table.rb
index dd22f44226..6ad294dc6c 100644
--- a/lib/arel/engines/sql/relations/table.rb
+++ b/lib/arel/engines/sql/relations/table.rb
@@ -3,10 +3,22 @@ module Arel
include Recursion::BaseCase
cattr_accessor :engine
- attr_reader :name, :engine
+ attr_reader :name, :engine, :table_alias, :options
- def initialize(name, engine = Table.engine)
- @name, @engine = name.to_s, engine
+ def initialize(name, options = {})
+ @name = name.to_s
+
+ if options.is_a?(Hash)
+ @options = options
+ @engine = options[:engine] || Table.engine
+ @table_alias = options[:as].to_s if options[:as].present?
+ else
+ @engine = options # Table.new('foo', engine)
+ end
+ end
+
+ def as(table_alias)
+ Table.new(name, options.merge(:as => table_alias))
end
def attributes
--
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