我是否需要手动为 DBIx::Class own_to 关系创建索引

Question

我正在使用 DBIx::Class 模块对我拥有的应用程序进行 ORM 方法。

我的人际关系遇到了一些问题。

我有以下模块

package MySchema::Result::ClusterIP;
use strict;
use warnings;

use base qw/DBIx::Class::Core/;

our $VERSION = '1.0';

__PACKAGE__->load_components(qw/InflateColumn::Object::Enum Core/);
__PACKAGE__->table('cluster_ip');

__PACKAGE__->add_columns( # Columns here );

__PACKAGE__->set_primary_key('objkey');
__PACKAGE__->belongs_to( 'configuration' => 'MySchema::Result::Configuration', 'config_key');
__PACKAGE__->belongs_to( 'cluster' => 'MySchema::Result::Cluster',
                            { 'foreign.config_key' => 'self.config_key',
                              'foreign.id'         => 'self.cluster_id'
                            }
                        );

以及

package MySchema::Result::Cluster;
use strict;
use warnings;

use base qw/DBIx::Class::Core/;

our $VERSION = '1.0';

__PACKAGE__->load_components(qw/InflateColumn::Object::Enum Core/);
__PACKAGE__->table('cluster');

__PACKAGE__->add_columns(  # Columns here );
__PACKAGE__->set_primary_key('objkey');
__PACKAGE__->belongs_to( 'configuration' => 'MySchema::Result::Configuration', 'config_key');
__PACKAGE__->has_many('cluster_ip'  => 'MySchema::Result::ClusterIP',
                            { 'foreign.config_key' => 'self.config_key',
                              'foreign.cluster_id' => 'self.id'
                            });

其他几个模块，但我不认为它们是相关的。

当我尝试部署此模式时，出现以下错误：

DBIx::Class::Schema::deploy(): DBI Exception: DBD::mysql::db do failed: Can't create table 'test.cluster_ip' (errno: 150) [
for Statement "CREATE TABLE `cluster_ip` (
  `objkey` smallint(5) unsigned NOT NULL auto_increment,
  `config_key` smallint(5) unsigned NOT NULL,
  `cluster_id` char(16) NOT NULL,
  INDEX `cluster_ip_idx_config_key_cluster_id` (`config_key`, `cluster_id`),
  INDEX `cluster_ip_idx_config_key` (`config_key`),
  PRIMARY KEY (`objkey`),
  CONSTRAINT `cluster_ip_fk_config_key_cluster_id` FOREIGN KEY (`config_key`, `cluster_id`) REFERENCES `cluster` (`config_key`, `id`) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT `cluster_ip_fk_config_key` FOREIGN KEY (`config_key`) REFERENCES `configuration` (`config_key`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB"] at test_deploy.pl line 18

 (running "CREATE TABLE `cluster_ip` (
  `objkey` smallint(5) unsigned NOT NULL auto_increment,
  `config_key` smallint(5) unsigned NOT NULL,
  `cluster_id` char(16) NOT NULL,
  INDEX `cluster_ip_idx_config_key_cluster_id` (`config_key`, `cluster_id`),
  INDEX `cluster_ip_idx_config_key` (`config_key`),
  PRIMARY KEY (`objkey`),
  CONSTRAINT `cluster_ip_fk_config_key_cluster_id` FOREIGN KEY (`config_key`, `cluster_id`) REFERENC
ES `cluster` (`config_key`, `id`) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT `cluster_ip_fk_config_key` FOREIGN KEY (`config_key`) REFERENCES `configuration` (`conf
ig_key`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB") at test_deploy.pl line 18

据我所知，MySQL 抱怨 FOREIGN KEY 约束，特别是对 (config_key, id< /code>）在cluster表中。从我对 MySQL 文档的阅读来看，这似乎是一个合理的抱怨，特别是关于 此文档页面。

这是我的问题。我是否缺少 DBIx::Class 模块中的某些内容？我意识到我可以显式创建必要的索引来匹配这个外键约束，但这似乎是重复性的工作。我应该做些什么来让这种情况隐式发生吗？

Answer 1

不确定这里发生了什么 SQL::Translator:: Producer::MySQL 应在部署的 DDL 开头插入 SETforeign_key_checks=0，这样就不会出现外键错误。我怀疑即使部署了整个 DDL 之后，某些东西还是被破坏了。您可以通过连接到数据库并运行以下语句来找出外键错误的确切性质：

SHOW INNODB STATUS;

Answer 2

我刚刚通过将以下内容添加到导致问题的结果类中来解决同样的问题：

sub sqlt_deploy_hook {
   my ($self, $sqlt_table) = @_;
   $sqlt_table->add_index(name => 'idx_my_column', fields => ['my_column']);
}