3 ways to operate a database

1. Execute native SQL PDO method.

Copy the codeThe code is as follows:

$sql = "";//Original SQL statement
xx::model()->dbConnection->createCommand($sql)->execute(); 

2. Active Record method
(1)New method

Copy the codeThe code is as follows:

$post=new Post;
$post->title='sample post';
$post->content='post body content';
$post->save(); 

(2) Criteria method
You can also use $condition to specify more complex query conditions. Without using strings, we can make $condition an instance of CDbCriteria, which allows us to specify conditions that are not limited to WHERE.

Copy the codeThe code is as follows:

$criteria=new CDbCriteria;
$criteria->select='title';  // Select only the 'title' column
$criteria->condition='postID=:postID';
$criteria->params=array(':postID'=>10);
$post=Post::model()->find($criteria);

An alternative to CDbCriteria is to pass an array to the find method. The keys and values of the array correspond to the attribute names and values of the criteria. The above example can be rewritten as follows:

Copy the codeThe code is as follows:

$post=Post::model()->find(array(
    'select'=>'title',
    'condition'=>'postID=:postID',
    'params'=>array(':postID'=>10),
)); 

When a query condition is about matching several columns by the specified value, we can use findByAttributes(). We make the $attributes parameter an array of values indexed by column names. In some frameworks, this task can be achieved by calling a method like findByNameAndTitle. But it often causes confusion, conflicts and, for example, case-sensitive column names.
3. Query Builder method

Copy the codeThe code is as follows:

$user = Yii::app()->db->createCommand()
    ->select('id, username, profile')
    ->from('tbl_user u')
    ->join('tbl_profile p', '=p.user_id')
    ->where('id=:id', array(':id'=>$id))
    ->queryRow();