字段名包含关联信息，不需额外再写include或者joins
原来activerecord仅支持inner join在最后，现在没有这个限制
不想用svn，直接下载可以到 https://rubyforge.org/projects/rquerypad/
Feature
=======
1. single name string decribe associations
2. support to mix inner join and outer join with any order
3. auto remove duplicated joins from other association in different depth
4. support :conditions, :order, :group
5. auto merge to original :include, :joins
Install
=======
ruby script/plugin install http://rquerypad.googlecode.com/svn/trunk/rquerypad
Example
=======
suppose the asscociations of User <-> Thread <-> Reply is 1:N:N
Ruby代码 
- @users = User.find(:all, :group => ["threads.created_at", "name"])
- generate:
- [:all, {:group=>"threads.created_at, users.name", :include=>[:threads]}]
- @users = User.find(:all, :conditions => ["threads_.replies.title = ?",
- "rquerypad"])
- generate:
- [:all, {:inner_joins=>["threads"], :conditions=>["replies.title = ?", "rquerypad"], :include=>[{:threads=>:replies}]}]
- #note: the :inner_joints is processed by rquerypad before sending sql to database
- @users = User.find(:all, :conditions => ["threads.replies.title = ? and threads.id = ?", "rquerypad", 1])
- generate:
- [:all, {:conditions=>["replies.title = ? and threads.id = ?", "rquerypad", 1], :include=>[{:threads=>:replies}]}]
- #note: single "threads" was removed from includes
@users = User.find(:all, :group => ["threads.created_at", "name"])
generate:
[:all, {:group=>"threads.created_at, users.name", :include=>[:threads]}]
@users = User.find(:all, :conditions => ["threads_.replies.title = ?",
"rquerypad"])
generate:
[:all, {:inner_joins=>["threads"], :conditions=>["replies.title = ?", "rquerypad"], :include=>[{:threads=>:replies}]}]
#note: the :inner_joints is processed by rquerypad before sending sql to database
@users = User.find(:all, :conditions => ["threads.replies.title = ? and threads.id = ?", "rquerypad", 1])
generate:
[:all, {:conditions=>["replies.title = ? and threads.id = ?", "rquerypad", 1], :include=>[{:threads=>:replies}]}]
#note: single "threads" was removed from includes
Setup
=======
#to set debug model, in rails initialized script
$RQUERYPAD_DEBUG = true
#to support rails 1.2.6, in rails initialized script, such as environment.rb
#default support rails 2.0
$RQUERYPAD_RAILS = "1.2"
Test
=======
Note: current migrate script works only in rails 2.0
1.Prepare
the test depends on sqlite3 database, the following code should be add into your database.yml and place rquerypad.rb(copy from test.rb) in config/environment
rquerypad:
adapter: sqlite3
database: vendor/plugins/rquerypad/test/db.rquerypad
timeout: 5000
2.database migrate
execute the following script
rake migrate
3.start test
execute the following script
rake
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