Yii2.0数据库查询实例（三）

常用查询：

// WHERE admin_id >= 10 LIMIT 0,10
 User::find()->select('*')->where(['>=', 'admin_id', 10])->offset(0)->limit(10)->all()

// SELECT `id`, (SELECT COUNT(*) FROM `user`) AS `count` FROM `post`   
 $subQuery = (new Query())->select('COUNT(*)')->from('user');    
 $query = (new Query())->select(['id', 'count' => $subQuery])->from('post');

 // SELECT DISTINCT `user_id` ... 
 User::find()->select('user_id')->distinct();

更新：

//update();
//runValidation boolen 是否通过validate()校验字段 默认为true 
//attributeNames array 需要更新的字段 
$model->update($runValidation , $attributeNames);  

//updateAll();
//update customer set status = 1 where status = 2
Customer::updateAll(['status' => 1], 'status = 2'); 

//update customer set status = 1 where status = 2 and uid = 1;
Customer::updateAll(['status' => 1], ['status'=> '2','uid'=>'1']);

删除：

直接 model 删除

$model = User::find($id);
$model->delete();


带有条件的删除

$connection ->createCommand()
            ->delete('tbl_user', 'status = 0')
            ->execute();


使用 Query 查询删除

$connection ->createCommand('DELETE FROM tbl_user WHERE userid=:userid')
            ->execute();


使用预处理语句删除
方法一

$model = $connection->createCommand('DELETE FROM tbl_user WHERE userid=:userid');
$model->bindParam(':userid', $userid);
$userid = 5;
$model->execute();

方法二

在 Yii2 使用预处理语句删除多个用户。

$model = $connection->createCommand('DELETE FROM tbl_user WHERE userid=:userid');
$model->bindParam(':userid', $userid);
// delete user 1
$userid = 1;
$model->execute();
// delete user 2
$userid = 2;
$model->execute();


查找并且删除

$user = User::findOne(2);
$user->delete();
// 输出语句
// DELETE FROM `tbl_user` WHERE `id`='2'

deleteAll() 删除多个
如果你不指定任何条件下,该方法将删除表中的所有行。例如删除用户表中状态条件是 active 和年龄大于20的用户。

方法一

User::deleteAll('status = :status AND age > :age', [':age' => 20, ':status' => 'active']);
//Output Query
//DELETE FROM `tbl_user` WHERE status = 'active' AND age > 20

方法二

User::deleteAll([
        'and',
        'type = :type_id',
        ['not in', 'usercategoryid', $categoriesList]
    ],
    [
        ':type_id' => 2
    ]);
//Output Query
//DELETE FROM `tbl_user` WHERE (type = 2) AND (`usercategoryid` NOT IN (1, 2, 3))

批量插入：

Yii::$app->db->createCommand()->batchInsert(UserModel::tableName(), ['user_id','username'], [
    ['1','test1'],
    ['2','test2'],
    ['3','test3'],   
])->execute();

查看执行sql

//UserModel 
$query = UserModel::find()->where(['status'=>1]); 
echo $query->createCommand()->getRawSql();