原理迁移：为mysql和postgresql创建代码 [英] Doctrine migrations: create code for mysql and postgresql

问题描述

我在Symfony 3.4.4项目中使用Doctrine ORM 2.6.1。
我的某些实例在MySQL数据库上工作，某些在Postgresql上工作，还有一些安装甚至可以访问MicosoftSQL服务器。无需对我的项目或实体进行任何特殊更改即可正常工作，我只需要配置相应的连接参数。

I am using Doctrine ORM 2.6.1 in a Symfony 3.4.4 project. Some of my instances work on a MySQL database, some on Postgresql, and a few installations even access a MicosoftSQL server. This works fine without any special changes to my project or entities, I only have to configure the corresponding connection parameters.

但是：如果我创建迁移，则在迁移文件中只会创建与当前数据库连接兼容的语句。

But: if I create migrations, only statements compatible with the current database connection are created in the migration file.

我使用postgres连接开发，所以我只生成postgresql语句，例如：

I develop with a postgres-conncection, so I only produce postgresql-statements, like:

class Version20180430083616 extends AbstractMigration
{
    public function up(Schema $schema)
    {
        // this up() migration is auto-generated, please modify it to your needs
        $this->abortIf($this->connection->getDatabasePlatform()->getName() !== 'postgresql', 'Migration can only be executed safely on \'postgresql\'.');

        $this->addSql('DELETE FROM document_category');
        $this->addSql('DROP SEQUENCE document_category_id_seq CASCADE');
        $this->addSql('DROP TABLE document_category');
    }

    public function down(Schema $schema)
    {
        // this down() migration is auto-generated, please modify it to your needs
        $this->abortIf($this->connection->getDatabasePlatform()->getName() !== 'postgresql', 'Migration can only be executed safely on \'postgresql\'.');
        //...
    }
}

我的问题：如何告诉迁移捆绑包为每个平台创建语句，例如：

My Question: How can I tell the migrations bundle to create statements for each platform, like:

class Version20180430083616 extends AbstractMigration
{
    public function up(Schema $schema)
    {
        // this up() migration is auto-generated, please modify it to your needs
        if($this->connection->getDatabasePlatform()->getName() == 'postgresql'){

            $this->addSql('DELETE FROM document');
            $this->addSql('DELETE FROM document_category');
            $this->addSql('DROP SEQUENCE document_category_id_seq CASCADE');
            $this->addSql('DROP TABLE document_category');
        } else if($this->connection->getDatabasePlatform()->getName() == 'mysql'){
            ...
        } else if ($this->connection->getDatabasePlatform()->getName() == 'mssql') { // MicrosoftSQL ?
            ...
        }
    }
}

编辑：

因此，我认为我的问题的唯一解决方案是定义多个数据库连接和实体管理器，并始终创建一个每个连接类型的不同迁移。根据这篇文章，我可以将几个连接定义为：

So, I think the only solution to my problem is to define multiple database connections and entity managers, and to always create a distinct migration for each connection type. According to this article, I can define several connections as:

推荐答案

我找到了可行的解决方案：

I found a doable solution:

inf config.yml我定义了一个连接每种数据库类型一个EntityManager：

inf config.yml I define one connection and one EntityManager per database type:

doctrine:
    dbal:
        default_connection: pgdb
        connections:
            pgdb:
                driver: pdo_pgsql
                host: db
                port: 5432
                name: pgdb
                user: postgres
                password: example
                charset: utf8
                mapping_types:
                    enum: string
            mysql:
                driver: pdo_mysql
                host: mysqlhost
                port: 3306
                name: mydb
                dbname: mydb
                user: root
                password: xxx
                charset: utf8mb4
                default_table_options:
                    collate: utf8mb4_unicode_ci
                mapping_types:
                    enum: string
            mssql:
                driver: pdo_sqlsrv
                host: mssqlhost
                port: 1433
                name: msdb
                dbname: testdb
                user: sa
                password: xxx
                charset: utf8
                mapping_types:
                    enum: string

    orm:
        auto_generate_proxy_classes:  false
        proxy_dir:            '%kernel.cache_dir%/doctrine/orm/Proxies'
        proxy_namespace:      Proxies
        entity_managers:
            default:
                connection: pgdb
                naming_strategy: doctrine.orm.naming_strategy.underscore
                mappings:
                    AppBundle: ~ 
            my:
                connection: mydb
                naming_strategy: doctrine.orm.naming_strategy.underscore
                mappings:
                    AppBundle: ~
            ms:
                connection: msdb
                naming_strategy: doctrine.orm.naming_strategy.underscore
                mappings:
                    AppBundle: ~

然后，我可以发出diff命令3次，而不是只发出一次

Then, I can issue the diff-command 3 times instead of only once

$ bin/console doctrine:migrations:diff --em=default
$ bin/console doctrine:migrations:diff --em=my
$ bin/console doctrine:migrations:diff --em=ms

这将创建三个迁移，每个迁移以隔离线开始：

This creates three migrations each starting with a fence line:

$this->abortIf($this->connection->getDatabasePlatform()->getName() !== 'mssql', 'Migration can only be executed safely on \'mssql\'.');

其中，我将 abortIf 交换为 skipIf ，这样，如果当前迁移是针对其他数据库类型，则迁移过程不会中止，而只是跳过：

in which I exchange abortIf by skipIf, such that the migration process is not aborted if the current migration if for a different database type, but just skipped:

$this->skipIf($this->connection->getDatabasePlatform()->getName() !== 'mssql', 'Migration can only be executed safely on \'mssql\'.');

我希望这对某人有帮助。

I hope this helps somebody.

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