本文实例讲述了Yii2数据库操作常用方法。分享给大家供大家参考，具体如下：
查询：
// find the customers whose primary key value is 10
$customers = Customer::findAll(10);
$customer = Customer::findOne(10);
// the above code is equivalent to:
$customers = Customer::find()->where(['id' => 10])->all();
// find the customers whose primary key value is 10, 11 or 12.
$customers = Customer::findAll([10, 11, 12]);
$customers = Customer::find()->where(['IN','id',[10,11,12]])->all();
// the above code is equivalent to:
$customers = Customer::find()->where(['id' => [10, 11, 12]])->all();
// find customers whose age is 30 and whose status is 1
$customers = Customer::findAll(['age' => 30, 'status' => 1]);
// the above code is equivalent to:
$customers = Customer::find()->where(['age' => 30, 'status' => 1])->all();
// use params binding
$customers = Customer::find()->where('age=:age AND status=:status')->addParams([':age'=>30,':status'=>1])->all();
// use index
$customers = Customer::find()->indexBy('id')->where(['age' => 30, 'status' => 1])->all();
// get customers count
$count = Customer::find()->where(['age' => 30, 'status' => 1])->count();
// add addition condition
$customers = Customer::find()->where(['age' => 30, 'status' => 1])->andWhere('score > 100')->orderBy('id DESC')->offset(5)->limit(10)->all();
// find by sql
$customers = Customer::findBySql('SELECT * FROM customer WHERE age=30 AND status=1 AND score>100 ORDER BY id DESC LIMIT 5,10')->all();
修改：
// update status for customer-10 $customer = Customer::findOne(10); $customer->status = 1; $customer->update(); // the above code is equivalent to: Customer::updateAll(['status' => 1], 'id = :id',[':id'=>10]);
删除：
// delete customer-10 Customer::findOne(10)->delete(); // the above code is equivalent to: Customer::deleteAll(['status' => 1], 'id = :id',[':id'=>10]);
----------------使用子查询----------------------
$subQuery = (new Query())->select('COUNT(*)')->from('customer');
// SELECT `id`, (SELECT COUNT(*) FROM `customer`) AS `count` FROM `customer`
$query = (new Query())->select(['id', 'count' => $subQuery])->from('customer');
----------------手写SQL-----------------------
// select
$customers = Yii::$app->db->createCommand('SELECT * FROM customer')->queryAll();
// update
Yii::$app->db->createCommand()->update('customer',['status'=>1],'id=10')->execute();
// delete
Yii::$app->db->createCommand()->delete('customer','id=10')->execute();
//transaction
// outer
$transaction1 = $connection->beginTransaction();
try {
$connection->createCommand($sql1)->execute();
// internal
$transaction2 = $connection->beginTransaction();
try {
$connection->createCommand($sql2)->execute();
$transaction2->commit();
} catch (Exception $e) {
$transaction2->rollBack();
}
$transaction1->commit();
} catch (Exception $e) {
$transaction1->rollBack();
}
---------------主从配置----------------------
[
'class' => 'yii\db\Connection',
// master
'dsn' => 'dsn for master server',
'username' => 'master',
'password' => '',
// slaves
'slaveConfig' => [
'username' => 'slave',
'password' => '',
'attributes' => [
// use a smaller connection timeout
PDO::ATTR_TIMEOUT => 10,
],
],
'slaves' => [
['dsn' => 'dsn for slave server 1'],
['dsn' => 'dsn for slave server 2'],
['dsn' => 'dsn for slave server 3'],
['dsn' => 'dsn for slave server 4'],
],
]
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希望本文所述对大家基于Yii框架的PHP程序设计有所帮助。
