Merge pull request #16231 from Envek/type_in_references

* Allow to specify a type for foreign key column in migrations
* unified the docs
* some cleanup in CHANGELOG

2 files changed, 25 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
index 98e6795f10..e44ccb7d81 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb
@@ -280,12 +280,22 @@ module ActiveRecord
         column(:updated_at, :datetime, options)
       end
 
+      # Adds a reference. Optionally adds a +type+ column, if <tt>:polymorphic</tt> option is provided.
+      # <tt>references</tt> and <tt>belongs_to</tt> are acceptable. The reference column will be an +integer+
+      # by default, the <tt>:type</tt> option can be used to specify a different type.
+      #
+      #  t.references(:user)
+      #  t.references(:user, type: "string")
+      #  t.belongs_to(:supplier, polymorphic: true)
+      #
+      # See SchemaStatements#add_reference
       def references(*args)
         options = args.extract_options!
         polymorphic = options.delete(:polymorphic)
         index_options = options.delete(:index)
+        type = options.delete(:type) || :integer
         args.each do |col|
-          column("#{col}_id", :integer, options)
+          column("#{col}_id", type, options)
           column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
           index(polymorphic ? %w(id type).map { |t| "#{col}_#{t}" } : "#{col}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
         end
@@ -500,11 +510,14 @@ module ActiveRecord
       end
 
       # Adds a reference. Optionally adds a +type+ column, if <tt>:polymorphic</tt> option is provided.
-      # <tt>references</tt> and <tt>belongs_to</tt> are acceptable.
+      # <tt>references</tt> and <tt>belongs_to</tt> are acceptable. The reference column will be an +integer+
+      # by default, the <tt>:type</tt> option can be used to specify a different type.
       #
       #  t.references(:user)
+      #  t.references(:user, type: "string")
       #  t.belongs_to(:supplier, polymorphic: true)
       #
+      # See SchemaStatements#add_reference
       def references(*args)
         options = args.extract_options!
         args.each do |ref_name|
@@ -519,6 +532,7 @@ module ActiveRecord
       #  t.remove_references(:user)
       #  t.remove_belongs_to(:supplier, polymorphic: true)
       #
+      # See SchemaStatements#remove_reference
       def remove_references(*args)
         options = args.extract_options!
         args.each do |ref_name|
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 5814c2b711..10753defc2 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -602,12 +602,18 @@ module ActiveRecord
       end
 
       # Adds a reference. Optionally adds a +type+ column, if <tt>:polymorphic</tt> option is provided.
+      # The reference column is an +integer+ by default, the <tt>:type</tt> option can be used to specify
+      # a different type.
       # <tt>add_reference</tt> and <tt>add_belongs_to</tt> are acceptable.
       #
-      # ====== Create a user_id column
+      # ====== Create a user_id integer column
       #
       #   add_reference(:products, :user)
       #
+      # ====== Create a user_id string column
+      #
+      #   add_reference(:products, :user, type: :string)
+      #
       # ====== Create a supplier_id and supplier_type columns
       #
       #   add_belongs_to(:products, :supplier, polymorphic: true)
@@ -619,7 +625,8 @@ module ActiveRecord
       def add_reference(table_name, ref_name, options = {})
         polymorphic = options.delete(:polymorphic)
         index_options = options.delete(:index)
-        add_column(table_name, "#{ref_name}_id", :integer, options)
+        type = options.delete(:type) || :integer
+        add_column(table_name, "#{ref_name}_id", type, options)
         add_column(table_name, "#{ref_name}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
         add_index(table_name, polymorphic ? %w[id type].map{ |t| "#{ref_name}_#{t}" } : "#{ref_name}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
       end