CODEWITHSUNDEEP
phpmysqlyii
user1597438
user1597438

Reputation: 2221

Command for database migration in Yii 2.0

While studying Yii 2.0, I've come across different ways people migrate their database. The first one, which I follow usually is from yii 2's guide.

Using this guide, I use commands such as yii migrate/create migrationfile and yii migrate

Normally inside my migration file up(), method I'd insert code like so:

$this->createTable('news', [
        'id' => Schema::TYPE_PK,
        'title' => Schema::TYPE_STRING . ' NOT NULL',
        'content' => Schema::TYPE_TEXT,
]);

However, I've also seen some tutorials such as this one which uses a slightly different command and code in the migration file. From the second tutorial, I've used php yii migrate/create migrationfile

While the syntax used in the migration file up() method was something like so:

return $this->createTable('posts', [
        'id' => 'INT PRIMARY KEY AUTO_INCREMENT',
        'title' => 'VARCHAR(255)',
        'content' => 'TEXT',

Now, this has resulted in number of questions. 1. Is there are difference between php yii and yii command? 2. What's the difference between using Schema:: vs not using it? Is it a better approach in migrating the database since it's what's written on Yii's guide to migrations or is it just a matter of preference which one to use?

Upvotes: 3

Views: 1311

Answers (1)

laszlovl
laszlovl

Reputation: 491

1) Using yii and php yii is exactly the same. If you check out the yii file, you'll see this on the first line: #!/usr/bin/env php. This is called the "shebang" syntax, and instructs your shell to automatically execute the yii script using the php binary. See: https://en.wikipedia.org/wiki/Shebang_%28Unix%29

2) The difference here is flexibility. If you use the Schema::TYPE_PK syntax, Yii will automatically determine the exact column type based on your database backend. For example, Schema::TYPE_PK would translate to int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY in MySQL, but if you'd use Postgres as database, it would translate to serial NOT NULL PRIMARY KEY instead. [1]

In practice it's unlikely to make a difference which method you use, because you're probably not going to switch to a different type of database halfway through your project and thus there's no need for your migration scripts to be database-agnostic. Based on your preferences, you could opt for the Schema syntax for the extra flexibility, or for the hardcoded syntax to make your migration definitions more clear to anyone reading them in the future.

[1] See https://github.com/yiisoft/yii2/blob/master/framework/db/pgsql/QueryBuilder.php#L21 and https://github.com/yiisoft/yii2/blob/master/framework/db/mysql/QueryBuilder.php#L24

Upvotes: 6

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