MariaDB 10.0.20 服务器上的 Ruby on Rails 外键迁移不适用

Question

我正在尝试在我的 Ruby on rails 项目上应用数据库迁移，该项目定义了引用和外键约束。

迁移本身在开发 Sqlite3 数据库以及使用 Aria 存储引擎的 MariaDB 服务器上运行良好。为了支持外键约束，我们在实时 MariaDB 10 服务器中使用 InnoDB（此处为：XtraDB）存储引擎。

在实时应用迁移时，它会失败并显示以下错误消息。

== 20150831210234 AddStyleToPiece: migrating ==================================
-- add_reference(:nv_pieces, :style, {:index=>true, :foreign_key=>true})
rake aborted!
StandardError: An error has occurred, all later migrations canceled:

Mysql2::Error: Table storage engine 'InnoDB' does not support the create option 'TRANSACTIONAL=1': ALTER TABLE `nv_pieces` ADD `style_id` int(11)/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:305:in `query'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:305:in `block in execute'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract_adapter.rb:473:in `block in log'
/usr/local/rvm/gems/ruby-2.1.5/gems/activesupport-4.2.4/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract_adapter.rb:467:in `log'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:305:in `execute'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/mysql2_adapter.rb:231:in `execute'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/schema_statements.rb:393:in `add_column'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/connection_adapters/abstract/schema_statements.rb:663:in `add_reference'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/migration.rb:662:in `block in method_missing'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/migration.rb:631:in `block in say_with_time'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/migration.rb:631:in `say_with_time'
/usr/local/rvm/gems/ruby-2.1.5/gems/activerecord-4.2.4/lib/active_record/migration.rb:651:in `method_missing'
/srv/httpd/rails-app/db/migrate/20150831210234_add_style_to_piece.rb:3:in `change'

我知道 MariaDB 服务器不支持 XtraDB 存储引擎的 TRANSACTIONAL。

这似乎是 mysql2 gem、libmariadbclient 和服务器之间的一致性问题，但我找不到生成语句的位置。

Answer 1

TRANSACTIONAL 仅适用于 Aria 表。

参考： https://mariadb.com/kb/en/mariadb/create-table/#transactional

所以在创建 InnoDB/XtraDB 表时不要使用它。

支持外键。

Answer 2

我终于自己弄明白了。

在 gem 源、rails 本身甚至 MariaDB 客户端库中没有发现任何 TRANSACTIONAL=1 的提示后，我尝试了 MariaDB。

该语句不包含 TRANSACTIONAL 参数。

这似乎是 MariaDB 10.0.21 中的一个错误。如果表是作为 MyISAM 或 ARIA 引擎创建的，或者在过去的某个时间转换为此引擎类型，则稍后转换为 INNODB 和任何后续的 ALTER TABLE 语句都会产生警告。

这可以使用以下 SQL 重现：

CREATE DATABASE testdb;
CONNECT testdb;
CREATE TABLE testtable (id INT(11)) ENGINE=INNODB;
ALTER TABLE testtable ENGINE=INNODB;
ALTER TABLE testtable ENGINE=INNODB;
ALTER TABLE testtable ENGINE=ARIA TRANSACTIONAL=1;
ALTER TABLE testtable ENGINE=INNODB;
SHOW WARNINGS;
ALTER TABLE testtable ENGINE=INNODB;
SHOW WARNINGS;

结果：

MariaDB [(none)]> connect testdb;
Connection id:    6698
Current database: testdb

MariaDB [testdb]> create table testtable (id INT(11)) ENGINE=INNODB;
Query OK, 0 rows affected (0.30 sec)

MariaDB [testdb]> alter table testtable ENGINE=INNODB;
Query OK, 0 rows affected (0.35 sec)
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [testdb]> alter table testtable ENGINE=INNODB;
Query OK, 0 rows affected (0.36 sec)
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [testdb]> alter table testtable ENGINE=ARIA TRANSACTIONAL=1;
Query OK, 0 rows affected (0.49 sec)
Records: 0  Duplicates: 0  Warnings: 0

MariaDB [testdb]> alter table testtable ENGINE=INNODB;
Query OK, 0 rows affected, 1 warning (0.54 sec)
Records: 0  Duplicates: 0  Warnings: 1

MariaDB [testdb]> show warnings;
+---------+------+------------------------------------------------------------------------------------+
| Level   | Code | Message                                                                            |
+---------+------+------------------------------------------------------------------------------------+
| Warning | 1478 | Table storage engine 'InnoDB' does not support the create option 'TRANSACTIONAL=1' |
+---------+------+------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

MariaDB [testdb]> alter table testtable ENGINE=INNODB;
Query OK, 0 rows affected, 1 warning (0.39 sec)
Records: 0  Duplicates: 0  Warnings: 1

MariaDB [testdb]> show warnings;
+---------+------+------------------------------------------------------------------------------------+
| Level   | Code | Message                                                                            |
+---------+------+------------------------------------------------------------------------------------+
| Warning | 1478 | Table storage engine 'InnoDB' does not support the create option 'TRANSACTIONAL=1' |
+---------+------+------------------------------------------------------------------------------------+
1 row in set (0.00 sec)