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Qiang Xue
2014-08-24 12:17:24 -04:00
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docs/guide/db-migrations.md
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@ -350,9 +350,10 @@ yii migrate --db=db2
The above command will apply *all* migrations found in the default migration path to the `db2` database.
If your application works with multiple databases, some migrations should be applied to one database while
some others should be applied to another database. In this case, it is recommended that you create a base
migration class for each different database and override the [[yii\db\Migration::init()]] method like the following,
If your application works with multiple databases, it is possible that some migrations should be applied
to one database while some others should be applied to another database. In this case, it is recommended that
you create a base migration class for each different database and override the [[yii\db\Migration::init()]]
method like the following,
```php
public function init()
@ -362,13 +363,13 @@ public function init()
}
```
If a migration needs to be applied to one database, you create a migration class by extending from the corresponding
base migration class.
To create a migration that should be applied to a particular database, simply extend from the corresponding
base migration class. Now if you run the `yii migrate` command, each migration will be applied to its corresponding database.
Now if you run the `yii migrate` command, each migration will be applied to the corresponding database.
Because each migration has harcoded the DB connection, the `--db` option of the `migrate` command will have no effect.
> Info: Because each migration uses hardcoded DB connection, the `--db` option of the `migrate` command will
have no effect. Also note that the migration history will be stored in the default `db` database.
If you still want to support changing DB connection via the `--db` option, you may take the following alternative
If you want to support changing DB connection via the `--db` option, you may take the following alternative
approach to work with multiple databases.
For each database, create a migration path and save all corresponding migration classes there. To apply migrations,
@ -379,3 +380,5 @@ yii migrate --migrationPath=@app/migrations/db1 --db=db1
yii migrate --migrationPath=@app/migrations/db2 --db=db2
...
```
> Info: The above approach stores the migration history in different databases specified via the `--db` option.