提交 b2816ae9 编写于 作者: A Akira Matsuda

:joins => joins

上级 c4bd4777
......@@ -763,43 +763,43 @@ def association_instance_set(name, association)
# second time, the table is aliased as <tt>#{reflection_name}_#{parent_table_name}</tt>.
# Indexes are appended for any more successive uses of the table name.
#
# Post.all :joins => :comments
# Post.joins(:comments)
# # => SELECT ... FROM posts INNER JOIN comments ON ...
# Post.all :joins => :special_comments # STI
# Post.joins(:special_comments) # STI
# # => SELECT ... FROM posts INNER JOIN comments ON ... AND comments.type = 'SpecialComment'
# Post.all :joins => [:comments, :special_comments] # special_comments is the reflection name, posts is the parent table name
# Post.joins(:comments, :special_comments) # special_comments is the reflection name, posts is the parent table name
# # => SELECT ... FROM posts INNER JOIN comments ON ... INNER JOIN comments special_comments_posts
#
# Acts as tree example:
#
# TreeMixin.all :joins => :children
# TreeMixin.joins(:children)
# # => SELECT ... FROM mixins INNER JOIN mixins childrens_mixins ...
# TreeMixin.all :joins => {:children => :parent}
# TreeMixin.joins(:children => :parent)
# # => SELECT ... FROM mixins INNER JOIN mixins childrens_mixins ...
# INNER JOIN parents_mixins ...
# TreeMixin.all :joins => {:children => {:parent => :children}}
# TreeMixin.joins(:children => {:parent => :children})
# # => SELECT ... FROM mixins INNER JOIN mixins childrens_mixins ...
# INNER JOIN parents_mixins ...
# INNER JOIN mixins childrens_mixins_2
#
# Has and Belongs to Many join tables use the same idea, but add a <tt>_join</tt> suffix:
#
# Post.all :joins => :categories
# Post.joins(:categories)
# # => SELECT ... FROM posts INNER JOIN categories_posts ... INNER JOIN categories ...
# Post.all :joins => {:categories => :posts}
# Post.joins(:categories => :posts)
# # => SELECT ... FROM posts INNER JOIN categories_posts ... INNER JOIN categories ...
# INNER JOIN categories_posts posts_categories_join INNER JOIN posts posts_categories
# Post.all :joins => {:categories => {:posts => :categories}}
# Post.joins(:categories => {:posts => :categories})
# # => SELECT ... FROM posts INNER JOIN categories_posts ... INNER JOIN categories ...
# INNER JOIN categories_posts posts_categories_join INNER JOIN posts posts_categories
# INNER JOIN categories_posts categories_posts_join INNER JOIN categories categories_posts_2
#
# If you wish to specify your own custom joins using a <tt>:joins</tt> option, those table
# If you wish to specify your own custom joins using <tt>joins</tt> method, those table
# names will take precedence over the eager associations:
#
# Post.all :joins => :comments, :joins => "inner join comments ..."
# Post.joins(:comments).joins("inner join comments ...")
# # => SELECT ... FROM posts INNER JOIN comments_posts ON ... INNER JOIN comments ...
# Post.all :joins => [:comments, :special_comments], :joins => "inner join comments ..."
# Post.joins(:comments, :special_comments).joins("inner join comments ...")
# # => SELECT ... FROM posts INNER JOIN comments comments_posts ON ...
# INNER JOIN comments special_comments_posts ...
# INNER JOIN comments ...
......
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