yii2.0增删改查

Posted 2020-08-13

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//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

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ActiveRecord::hasMany()：返回对应关系的多条记录


应用实例

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//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

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//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():

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//查询key值为10的客户
$customer = Customer::findOne(10);
$customer = Customer::find()->where([‘id‘ => 10])->one();

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//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();

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//查询key值为10的所有客户
$customers = Customer::findAll(10);
$customers = Customer::find()->where([‘id‘ => 10])->all();

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//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();

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//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：

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//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：

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//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]]:

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//SQL:`(type IN (7, 8, 9) OR (id IN (1, 2, 3)))`
$cond = [‘or‘, [‘type‘ => [7, 8, 9]], [‘id‘ => [1, 2, 3]]

[[not]]:

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//SQL:`NOT (attribute IS NULL)`
$cond = [‘not‘, [‘attribute‘ => null]]

[[between]]: not between 用法相同

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//SQL:`id BETWEEN 1 AND 10`
$cond = [‘between‘, ‘id‘, 1, 10]

[[in]]: not in 用法类似

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//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])]