rename `Relation#uniq` to `Relation#distinct`. `#uniq` still works.

The similarity of `Relation#uniq` to `Array#uniq` is confusing. Since our
Relation API is close to SQL terms I renamed `#uniq` to `#distinct`.

There is no deprecation. `#uniq` and `#uniq!` are aliases and will continue
to work. I also updated the documentation to promote the use of `#distinct`.

4 files changed, 10 insertions, 11 deletions

diff --git a/activerecord/test/models/author.rb b/activerecord/test/models/author.rb
index 8423411474..a96899ae10 100644
--- a/activerecord/test/models/author.rb
+++ b/activerecord/test/models/author.rb
@@ -30,8 +30,8 @@ class Author < ActiveRecord::Base
   has_many :comments_desc, -> { order('comments.id DESC') }, :through => :posts, :source => :comments
   has_many :limited_comments, -> { limit(1) }, :through => :posts, :source => :comments
   has_many :funky_comments, :through => :posts, :source => :comments
-  has_many :ordered_uniq_comments, -> { uniq.order('comments.id') }, :through => :posts, :source => :comments
-  has_many :ordered_uniq_comments_desc, -> { uniq.order('comments.id DESC') }, :through => :posts, :source => :comments
+  has_many :ordered_uniq_comments, -> { distinct.order('comments.id') }, :through => :posts, :source => :comments
+  has_many :ordered_uniq_comments_desc, -> { distinct.order('comments.id DESC') }, :through => :posts, :source => :comments
   has_many :readonly_comments, -> { readonly }, :through => :posts, :source => :comments
 
   has_many :special_posts
@@ -78,7 +78,7 @@ class Author < ActiveRecord::Base
   has_many :categories_like_general, -> { where(:name => 'General') }, :through => :categorizations, :source => :category, :class_name => 'Category'
 
   has_many :categorized_posts, :through => :categorizations, :source => :post
-  has_many :unique_categorized_posts, -> { uniq }, :through => :categorizations, :source => :post
+  has_many :unique_categorized_posts, -> { distinct }, :through => :categorizations, :source => :post
 
   has_many :nothings, :through => :kateggorisatons, :class_name => 'Category'
 
@@ -91,7 +91,7 @@ class Author < ActiveRecord::Base
   has_many :post_categories, :through => :posts, :source => :categories
   has_many :tagging_tags,    :through => :taggings, :source => :tag
 
-  has_many :similar_posts, -> { uniq }, :through => :tags, :source => :tagged_posts
+  has_many :similar_posts, -> { distinct }, :through => :tags, :source => :tagged_posts
   has_many :distinct_tags, -> { select("DISTINCT tags.*").order("tags.name") }, :through => :posts, :source => :tags
 
   has_many :tags_with_primary_key, :through => :posts
diff --git a/activerecord/test/models/book.rb b/activerecord/test/models/book.rb
index ce81a37966..5458a28cc9 100644
--- a/activerecord/test/models/book.rb
+++ b/activerecord/test/models/book.rb
@@ -2,7 +2,7 @@ class Book < ActiveRecord::Base
   has_many :authors
 
   has_many :citations, :foreign_key => 'book1_id'
-  has_many :references, -> { uniq }, :through => :citations, :source => :reference_of
+  has_many :references, -> { distinct }, :through => :citations, :source => :reference_of
 
   has_many :subscriptions
   has_many :subscribers, :through => :subscriptions
diff --git a/activerecord/test/models/liquid.rb b/activerecord/test/models/liquid.rb
index 6cfd443e75..69d4d7df1a 100644
--- a/activerecord/test/models/liquid.rb
+++ b/activerecord/test/models/liquid.rb
@@ -1,5 +1,4 @@
 class Liquid < ActiveRecord::Base
   self.table_name = :liquid
-  has_many :molecules, -> { uniq }
+  has_many :molecules, -> { distinct }
 end
-
diff --git a/activerecord/test/models/project.rb b/activerecord/test/models/project.rb
index 90273adafc..f893754b9f 100644
--- a/activerecord/test/models/project.rb
+++ b/activerecord/test/models/project.rb
@@ -1,11 +1,11 @@
 class Project < ActiveRecord::Base
-  has_and_belongs_to_many :developers, -> { uniq.order 'developers.name desc, developers.id desc' }
+  has_and_belongs_to_many :developers, -> { distinct.order 'developers.name desc, developers.id desc' }
   has_and_belongs_to_many :readonly_developers, -> { readonly }, :class_name => "Developer"
-  has_and_belongs_to_many :selected_developers, -> { uniq.select "developers.*" }, :class_name => "Developer"
+  has_and_belongs_to_many :selected_developers, -> { distinct.select "developers.*" }, :class_name => "Developer"
   has_and_belongs_to_many :non_unique_developers, -> { order 'developers.name desc, developers.id desc' }, :class_name => 'Developer'
   has_and_belongs_to_many :limited_developers, -> { limit 1 }, :class_name => "Developer"
-  has_and_belongs_to_many :developers_named_david, -> { where("name = 'David'").uniq }, :class_name => "Developer"
-  has_and_belongs_to_many :developers_named_david_with_hash_conditions, -> { where(:name => 'David').uniq }, :class_name => "Developer"
+  has_and_belongs_to_many :developers_named_david, -> { where("name = 'David'").distinct }, :class_name => "Developer"
+  has_and_belongs_to_many :developers_named_david_with_hash_conditions, -> { where(:name => 'David').distinct }, :class_name => "Developer"
   has_and_belongs_to_many :salaried_developers, -> { where "salary > 0" }, :class_name => "Developer"
 
   ActiveSupport::Deprecation.silence do