Yii2.0 增删改查
//关闭csrf
public $enableCsrfValidation = false;1.sql语句
//查询
$db=\Yii::$app->db ->createCommand("select * from 表名") ->queryAll();
//修改
$db=\Yii::$app->db ->createCommand()->update('表名',['字段名'=>要修改的值],'条件') ->execute();
// 删除
$db=\Yii::$app->db ->createCommand() ->delete('表名','条件') ->execute();
//添加
$db=\Yii::$app->db ->createCommand() ->insert('表名',['字段名'=>要添加的值],'条件') ->execute();//应用实例
Customer::find()->one(); 此方法返回一条数据；
Customer::find()->all(); 此方法返回所有数据；
Customer::find()->count(); 此方法返回记录的数量；
Customer::find()->average(); 此方法返回指定列的平均值；
Customer::find()->min(); 此方法返回指定列的最小值 ；
Customer::find()->max(); 此方法返回指定列的最大值 ；
Customer::find()->scalar(); 此方法返回值的第一行第一列的查询结果；
Customer::find()->column(); 此方法返回查询结果中的第一列的值；
Customer::find()->exists(); 此方法返回一个值指示是否包含查询结果的数据行；
Customer::find()->asArray()->one(); 以数组形式返回一条数据；
Customer::find()->asArray()->all(); 以数组形式返回所有数据；
Customer::find()->where($condition)->asArray()->one(); 根据条件以数组形式返回一条数据；
Customer::find()->where($condition)->asArray()->all(); 根据条件以数组形式返回所有数据；
Customer::find()->where($condition)->asArray()->orderBy('id DESC')->all(); 根据条件以数组形式返回所有数据,并根据ID倒序；
3.关联查询
ActiveRecord::hasOne()：返回对应关系的单条记录
ActiveRecord::hasMany()：返回对应关系的多条记录应用实例
//客户表Model：CustomerModel
//订单表Model：OrdersModel
//国家表Model：CountrysModel
//首先要建立表与表之间的关系
//在CustomerModel中添加与订单的关系
Class CustomerModel extends yiidbActiveRecord
{
...
public function getOrders()
{
//客户和订单是一对多的关系所以用hasMany
//此处OrdersModel在CustomerModel顶部别忘了加对应的命名空间
//id对应的是OrdersModel的id字段，order_id对应CustomerModel的order_id字段
return $this->hasMany(OrdersModel::className(), ['id'=>'order_id']);
}
public function getCountry()
{
//客户和国家是一对一的关系所以用hasOne
return $this->hasOne(CountrysModel::className(), ['id'=>'Country_id']);
}
....
}
// 查询客户与他们的订单和国家
CustomerModel::find()->with('orders', 'country')->all();
// 查询客户与他们的订单和订单的发货地址
CustomerModel::find()->with('orders.address')->all();
// 查询客户与他们的国家和状态为1的订单
CustomerModel::find()->with([
'orders' => function ($query) {
$query->andWhere('status = 1');
},
'country',
])->all();注：with中的orders对应getOrders
常见问题：
1.在查询时加了->select();如下，要加上order_id，即关联的字段（比如：order_id）比如要在select中，否则会报错：undefined index order_id
//查询客户与他们的订单和国家
CustomerModel::find()->select('order_id')->with('orders', 'country')->all();findOne()和findAll():
//查询key值为10的客户
$customer = Customer::findOne(10);
$customer = Customer::find()->where(['id' => 10])->one(); //查询年龄为30，状态值为1的客户
$customer = Customer::findOne(['age' => 30, 'status' => 1]);
$customer = Customer::find()->where(['age' => 30, 'status' => 1])->one(); //查询key值为10的所有客户
$customers = Customer::findAll(10);
$customers = Customer::find()->where(['id' => 10])->all(); //查询key值为10，11,12的客户
$customers = Customer::findAll([10, 11, 12]);
$customers = Customer::find()->where(['id' => [10, 11, 12]])->all(); //查询年龄为30，状态值为1的所有客户
$customers = Customer::findAll(['age' => 30, 'status' => 1]);
$customers = Customer::find()->where(['age' => 30, 'status' => 1])->all();where()条件：
$customers = Customer::find()->where($cond)->all();
$cond写法举例：
//SQL: (type = 1) AND (status = 2).
$cond = ['type' => 1, 'status' => 2]
//SQL:(id IN (1, 2, 3)) AND (status = 2)
$cond = ['id' => [1, 2, 3], 'status' => 2]
//SQL:status IS NULL
$cond = ['status' => null][[and]]:将不同的条件组合在一起，用法举例：
//SQL:`id=1 AND id=2`
$cond = ['and', 'id=1', 'id=2']
//SQL:`type=1 AND (id=1 OR id=2)`
$cond = ['and', 'type=1', ['or', 'id=1', 'id=2']][[or]]:
//SQL:`(type IN (7, 8, 9) OR (id IN (1, 2, 3)))`
$cond = ['or', ['type' => [7, 8, 9]], ['id' => [1, 2, 3]][[not]]:
//SQL:`NOT (attribute IS NULL)`
$cond = ['not', ['attribute' => null]][[between]]: not between 用法相同
//SQL:`id BETWEEN 1 AND 10`
$cond = ['between', 'id', 1, 10][[in]]: not in 用法类似
//SQL:`id IN (1, 2, 3)`
$cond = ['in', 'id', [1, 2, 3]]
//IN条件也适用于多字段
$cond = ['in', ['id', 'name'], [['id' => 1, 'name' => 'foo'], ['id' => 2, 'name' => 'bar']]]
//也适用于内嵌sql语句
$cond = ['in', 'user_id', (new Query())->select('id')->from('users')->where(['active' => 1])][[like]]:
//SQL:`name LIKE '%tester%'`
$cond = ['like', 'name', 'tester']
//SQL:`name LIKE '%test%' AND name LIKE '%sample%'`
$cond = ['like', 'name', ['test', 'sample']]
//SQL:`name LIKE '%tester'`
$cond = ['like', 'name', '%tester', false][[exists]]: not exists用法类似
//SQL:EXISTS (SELECT "id" FROM "users" WHERE "active"=1)
$cond = ['exists', (new Query())->select('id')->from('users')->where(['active' => 1])]此外，您可以指定任意运算符如下
//SQL:`id >= 10`
$cond = ['>=', 'id', 10]
//SQL:`id != 10`
$cond = ['!=', 'id', 10]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：
$model = Customer::findOne($id);
$model->delete();
$model->deleteAll(['id'=>1]);批量插入：
Yii::$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();