数据库查询实例(findOne、findAll、where)

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]