yiic 数据库迁移工具
2014-07-21 18:54 youxin 阅读(580) 评论(0) 编辑 收藏 举报数据库的结构也同源代码一样随着我们开发的进行而不断的发生着改变。在开发过程中,一般的我们需要像管理我们的源代码一样记录下数据库结构的整个变化过程,以便代码还原到指定版本后,数据库能同步的还原到指定的版本与源代码同步。为了方便这一操作,Yii给我们提供了Yiic migrate 这个命令,对应的也有一个 CDbMigration 类来描述各个版本之间的信息,从而实现通过命令来还原或者更新数据库到指定的版本。
cd protected
yiic migrate create tbl_user
F:\xampp\htdocs\swsg10\backend\protected>yiic help migrate
USAGE
yiic migrate [action] [parameter]
DESCRIPTION
This command provides support for database migrations. The optional
'action' parameter specifies which specific migration task to perform.
It can take these values: up, down, to, create, history, new, mark.
If the 'action' parameter is not given, it defaults to 'up'.
Each action takes different parameters. Their usage can be found in
the following examples.
EXAMPLES
* yiic migrate
Applies ALL new migrations. This is equivalent to 'yiic migrate up'.
* yiic migrate create create_user_table
Creates a new migration named 'create_user_table'.
* yiic migrate up 3
Applies the next 3 new migrations.
* yiic migrate down
Reverts the last applied migration.
* yiic migrate down 3
Reverts the last 3 applied migrations.
* yiic migrate to 101129_185401
Migrates up or down to version 101129_185401.
* yiic migrate mark 101129_185401
Modifies the migration history up or down to version 101129_185401.
No actual migration will be performed.
* yiic migrate history
Shows all previously applied migration information.
* yiic migrate history 10
Shows the last 10 applied migrations.
* yiic migrate new
Shows all new migrations.
* yiic migrate new 10
Shows the next 10 migrations that have not been applied.
F:\xampp\htdocs\swsg10\backend\protected>
1 生成数据库表: yiic migrate
2 降低N个版本: yiic migrate down n
3 升级N个版本: yiic migrate up n
4 升级到指定版本: yiic migrate to 101129_185401
5 重新执行步骤: yiic migrate redo [step]
6 显示迁移历史: yiic migrate history [limit]
7 显示未应用的迁移: yiic migrate new [limit]
这里有两点需要说明一下:
- 执行yiic命令是需要配置好相关的环境变量面的Yiic命令找不到Yii框架的代码。
- 命令中 tbl_user 是我们要做的更改的简要说明,这里我用的表明,当然也可以是其它的说明,一般只作为 migrate 生成类名的一部分,方便理解。帖一下执行过程吧
E:\WebRoot\TrackStar\protected>yiic migrate create tbl_user
Yii Migration Tool v1.0 (based on Yii v1.1.9-dev)
Create new migration 'E:\WebRoot\TrackStar\protected\migrations\m120406_063814_tbl_user.php'? [yes|no] yes
New migration created successfully.
E:\WebRoot\TrackStar\protected>
执行完这个命令就会在 /protected/migrations 文件夹中生成要处理的PHP文件,如下图:
1 class m120406_063814_tbl_user extends CDbMigration{
2 public function up(){
3 // 新数据库版本的代码,可以是创建新表、修改表结构、增删数据 等等
4 // 具体可以参考 Yii文档的 CDbMigration 类说明。
5 $this->createTable('tbl_user', array(
6 'id' => 'pk',
7 'username' => 'VARCHAR(128) NOT NULL',
8 'password' => 'VARCHAR(128) NOT NULL',
9 'email' => 'VARCHAR(128) NOT NULL'
10 ));
11 }
12
13 public function down(){
14 // 这里是对应up写的还原部分。
15 // 如果up函数中写的是建表,这里可以删除表,如果up中写的是增加新元素,这里可以是删除。
16 // 如果是初始版本,不允许还原的话,将此函数返回一个false即可。
17 $this->dropTable('tbl_user');
18 }
19
20 /*
21 // 如果要迁移的数据牵扯多个表同步操作,可以通过下面两个方法来实现事务的迁移
22 public function safeUp(){
23 }
24
25 public function safeDown(){
26 }
27 */
28 }
以上代码我注释的很清楚了,我们的第一个版本就只是简单的创建了个tbl_user表,如果再还原到初始情况的话,就将这个表也drop掉。倘若你对于 createTable 之类的方法不了解,可以参考Yii文档的CDbMigration类说明,一般的百度一下就会有好多出来,如果实在找不到,我会在本文最后列出来。
在执行命令之前,我们需要修改下:/protected/config/console.php 中的配置,让命令能顺利的找到我们的数据库:
1 components'=>array(
2 ‘db'=>array(
3 'connectionString' => 'mysql:host=localhost;dbname=trackstar',
4 'emulatePrepare' => true,
5 'username' => 'root',
6 'password' => '',
7 'charset' => 'utf8',
8 ),
OK, 执行命令:
E:\WebRoot\TrackStar\protected>yiic migrate up
Yii Migration Tool v1.0 (based on Yii v1.1.9-dev)
Total 1 new migration to be applied:
m120406_063814_tbl_user
Apply the above migration? [yes|no] yes
*** applying m120406_063814_tbl_user
> create table tbl_user ... done (time: 0.056s)
*** applied m120406_063814_tbl_user (time: 0.067s)
Migrated up successfully.
E:\WebRoot\TrackStar\protected>
OK, 看我们的数据库:
数据库表成功建立,其中, tbl_migration 表是用来管理每次数据库操作过程的,暂不细说。
再还原回去:
E:\WebRoot\TrackStar\protected>yiic migrate down
Yii Migration Tool v1.0 (based on Yii v1.1.9-dev)
Total 1 migration to be reverted:
m120406_063814_tbl_user
Revert the above migration? [yes|no] yes
*** reverting m120406_063814_tbl_user
> drop table tbl_user ... done (time: 0.056s)
*** reverted m120406_063814_tbl_user (time: 0.069s)
Migrated down successfully.
E:\WebRoot\TrackStar\protected>
Ok,测试没问题了,我们再建一个新版本,用来想表中添加五条记录:
yiic migrate create tbl_user_adddata
生成的代码:
1 class m120406_072631_tbl_user_adddata extends CDbMigration
2 {
3 public function up(){
4 $this->insert('tbl_user', array('username' => 'test1', 'password' => 'pass1',
5 'email'=> 'test1@example.com'));
6 $this->insert('tbl_user', array('username' => 'test2', 'password' => 'pass2',
7 'email'=> 'test2@example.com'));
8 $this->insert('tbl_user', array('username' => 'test3', 'password' => 'pass3',
9 'email'=> 'test3@example.com'));
10 $this->insert('tbl_user', array('username' => 'test4', 'password' => 'pass4',
11 'email'=> 'test4@example.com'));
12 $this->insert('tbl_user', array('username' => 'test5', 'password' => 'pass5',
13 'email'=> 'test5@example.com'));
14
15 }
16
17 public function down(){
18 $this->delete('tbl_user', 'username = "test1"');
19 $this->delete('tbl_user', 'username = "test2"');
20 $this->delete('tbl_user', 'username = "test3"');
21 $this->delete('tbl_user', 'username = "test4"');
22