Merge pull request rails#12578 from jeradphelps/configurable_schema_migrations_table_name

Configurable name for schema_migrations table

Conflicts:
	activerecord/CHANGELOG.md

Author: rafaelfranca

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Allow for the name of the schema_migrations table to be configured.
+
+    *Jerad Phelps*
+
 *   Do not add to scope includes values from through associations.
     Fixed bug when providing `includes` in through association scope, and fetching targets.
 

activerecord/lib/active_record/model_schema.rb

@@ -32,6 +32,12 @@ module ModelSchema
       class_attribute :table_name_suffix, instance_writer: false
       self.table_name_suffix = ""
 
+      ##
+      # :singleton-method:
+      # Accessor for the name of the schema migrations table. By default, the value is "schema_migrations"
+      class_attribute :schema_migrations_table_name, instance_accessor: false
+      self.schema_migrations_table_name = "schema_migrations"
+
       ##
       # :singleton-method:
       # Indicates whether table names should be the pluralized versions of the corresponding class names.

activerecord/lib/active_record/schema_migration.rb

@@ -7,11 +7,11 @@ class SchemaMigration < ActiveRecord::Base
     class << self
 
       def table_name
-        "#{table_name_prefix}schema_migrations#{table_name_suffix}"
+        "#{table_name_prefix}#{ActiveRecord::Base.schema_migrations_table_name}#{table_name_suffix}"
       end
 
       def index_name
-        "#{table_name_prefix}unique_schema_migrations#{table_name_suffix}"
+        "#{table_name_prefix}unique_#{ActiveRecord::Base.schema_migrations_table_name}#{table_name_suffix}"
       end
 
       def table_exists?

activerecord/test/cases/migration_test.rb

@@ -311,14 +311,23 @@ def migrate(x)
   end
 
   def test_schema_migrations_table_name
+    original_schema_migrations_table_name = ActiveRecord::Migrator.schema_migrations_table_name
+
+    assert_equal "schema_migrations", ActiveRecord::Migrator.schema_migrations_table_name
     ActiveRecord::Base.table_name_prefix = "prefix_"
     ActiveRecord::Base.table_name_suffix = "_suffix"
     Reminder.reset_table_name
     assert_equal "prefix_schema_migrations_suffix", ActiveRecord::Migrator.schema_migrations_table_name
+    ActiveRecord::Base.schema_migrations_table_name = "changed"
+    Reminder.reset_table_name
+    assert_equal "prefix_changed_suffix", ActiveRecord::Migrator.schema_migrations_table_name
     ActiveRecord::Base.table_name_prefix = ""
     ActiveRecord::Base.table_name_suffix = ""
     Reminder.reset_table_name
-    assert_equal "schema_migrations", ActiveRecord::Migrator.schema_migrations_table_name
+    assert_equal "changed", ActiveRecord::Migrator.schema_migrations_table_name
+  ensure
+    ActiveRecord::Base.schema_migrations_table_name = original_schema_migrations_table_name
+    Reminder.reset_table_name
   end
 
   def test_proper_table_name_on_migrator

guides/source/configuring.md

@@ -261,6 +261,8 @@ config.middleware.delete "Rack::MethodOverride"
 
 * `config.active_record.table_name_suffix` lets you set a global string to be appended to table names. If you set this to `_northwest`, then the Customer class will look for `customers_northwest` as its table. The default is an empty string.
 
+* `config.active_record.schema_migrations_table_name` lets you set a string to be used as the name of the schema migrations table.
+
 * `config.active_record.pluralize_table_names` specifies whether Rails will look for singular or plural table names in the database. If set to true (the default), then the Customer class will use the `customers` table. If set to false, then the Customer class will use the `customer` table.
 
 * `config.active_record.default_timezone` determines whether to use `Time.local` (if set to `:local`) or `Time.utc` (if set to `:utc`) when pulling dates and times from the database. The default is `:utc` for Rails, although Active Record defaults to `:local` when used outside of Rails.