使用表前缀时报错 [ 未指定版本 ]

Yii版本：1.1.17-dev

$connection=new CDbConnection('mysql:host=localhost;dbname=test');
$sql='select * from {{user}}';
$res=$connection->createCommand($sql)->queryAll();

配置里面也加了tablePrefix

'connectionString' => 'mysql:host=localhost;dbname=test',
'emulatePrepare' => true,
'username' => 'root',
'password' => '123456',
'charset' => 'utf8',
'tablePrefix' => 'tbl_',

运行后提示SQL语法错误：

CDbCommand failed to execute the SQL statement: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '{user}}' at line 1. The SQL statement executed was: select * from {{user}}