diff options
Diffstat (limited to 'activerecord')
4 files changed, 58 insertions, 5 deletions
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md index 799a1c1a65..3ef21ab194 100644 --- a/activerecord/CHANGELOG.md +++ b/activerecord/CHANGELOG.md @@ -1,5 +1,20 @@ ## Rails 4.0.0 (unreleased) ## +* The length of the `version` column in the `schema_migrations` table + created by the `mysql2` adapter is 191 if the encoding is "utf8mb4". + + The "utf8" encoding in MySQL has support for a maximum of 3 bytes per character, + and only contains characters from the BMP. The recently added + [utf8mb4](http://dev.mysql.com/doc/refman/5.5/en/charset-unicode-utf8mb4.html) + encoding extends the support to four bytes. As of this writing, said encoding + is supported in the betas of the `mysql2` gem. + + Setting the encoding to "utf8mb4" has + [a few implications](http://dev.mysql.com/doc/refman/5.5/en/charset-unicode-upgrading.html). + This change addresses the max length for indexes, which is 191 instead of 255. + + *Xavier Noria* + * Counter caches on associations will now stay valid when attributes are updated (not just when records are created or destroyed), for example, when calling `update_attributes`. The following code now works: diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb index 20a5ca2baa..25b8aef617 100644 --- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb @@ -38,6 +38,15 @@ module ActiveRecord configure_connection end + MAX_INDEX_LENGTH_FOR_UTF8MB4 = 191 + def initialize_schema_migrations_table + if @config[:encoding] == 'utf8mb4' + ActiveRecord::SchemaMigration.create_table(MAX_INDEX_LENGTH_FOR_UTF8MB4) + else + ActiveRecord::SchemaMigration.create_table + end + end + def supports_explain? true end diff --git a/activerecord/lib/active_record/schema_migration.rb b/activerecord/lib/active_record/schema_migration.rb index 9830abe7d8..6077144265 100644 --- a/activerecord/lib/active_record/schema_migration.rb +++ b/activerecord/lib/active_record/schema_migration.rb @@ -13,18 +13,21 @@ module ActiveRecord "#{Base.table_name_prefix}unique_schema_migrations#{Base.table_name_suffix}" end - def self.create_table + def self.create_table(limit=nil) unless connection.table_exists?(table_name) - connection.create_table(table_name, :id => false) do |t| - t.column :version, :string, :null => false + version_options = {null: false} + version_options[:limit] = limit if limit + + connection.create_table(table_name, id: false) do |t| + t.column :version, :string, version_options end - connection.add_index table_name, :version, :unique => true, :name => index_name + connection.add_index table_name, :version, unique: true, name: index_name end end def self.drop_table if connection.table_exists?(table_name) - connection.remove_index table_name, :name => index_name + connection.remove_index table_name, name: index_name connection.drop_table(table_name) end end diff --git a/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb new file mode 100644 index 0000000000..9ecd901eac --- /dev/null +++ b/activerecord/test/cases/adapters/mysql2/schema_migrations_test.rb @@ -0,0 +1,26 @@ +require "cases/helper" + +module ActiveRecord + module ConnectionAdapters + class Mysql2Adapter + class SchemaMigrationsTest < ActiveRecord::TestCase + def test_initializes_schema_migrations_for_encoding_utf8mb4 + conn = ActiveRecord::Base.connection + + smtn = ActiveRecord::Migrator.schema_migrations_table_name + conn.drop_table(smtn) if conn.table_exists?(smtn) + + config = conn.instance_variable_get(:@config) + original_encoding = config[:encoding] + + config[:encoding] = 'utf8mb4' + conn.initialize_schema_migrations_table + + assert conn.column_exists?(smtn, :version, :string, limit: Mysql2Adapter::MAX_INDEX_LENGTH_FOR_UTF8MB4) + ensure + config[:encoding] = original_encoding + end + end + end + end +end |