Yii2框架操作数据库的方法分析【以mysql为例】_php实例_

 DROP TABLE IF EXISTS `pre_user`; CREATE TABLE `pre_user`( `id` int(11) AUTO_INCREMENT PRIMARY KEY, `username` varchar(255) NOT NULL, `password` varchar(32) NOT NULL DEFAULT '', `password_hash` varchar(255) NOT NULL DEFAULT '', `email` varchar(255) NOT NULL DEFAULT '', `status` smallint(6) NOT NULL DEFAULT 10, `created_at` smallint(6) NOT NULL DEFAULT 0, `updated_at` smallint(6) NOT NULL DEFAULT 0 )ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 

 'yii\db\Connection', 'dsn' => 'mysql:host=localhost;dbname=yii2', 'username' => 'root', 'password' => 'root', 'charset' => 'utf8mb4', 'tablePrefix' => 'pre_' ]; 

 var_dump(\Yii::$app->db); 

 // 接收表单的数据 $username = 'jack'; $sql = "INSERT INTO {{%user}} (username,status) VALUES (:username,:status)"; // 返回受影响行数 $row = \Yii::$app->db->createCommand($sql,['username'=>$username,'status'=>8])->execute(); // 获取自增ID echo \Yii::$app->db->getLastInsertID(); 

 $sql = "SELECT * FROM {{%user}} WHERE id>:id"; // 查询结果是一个二维数组 $userArr = \Yii::$app->db->createCommand($sql,['id'=>1])->queryAll(); // 如果要查询一个 $user = \Yii::$app->db->createCommand($sql,['id'=>1])->queryOne(); // 如果要返回单值 // 例如 select count(*)语句 $count = \Yii::$app->db->createCommand($sql,['id'=>1])->queryScalar(); echo $count;