Yii2数据库查询的各种方法

Query Builder

$rows = (new \yii\db\Query())  

    ->select(['dyn_id', 'dyn_name'])  

    ->from('zs_dynasty')  

    ->where(['between','dyn_id', 1,30])  

    ->limit(10)  

    ->all();  

print_r($rows);

 

use yii\db\Query;  

$query = (new Query())  

    ->from('user')  

    ->orderBy('id');  

SELECT

$query->select('*')->  

select('dyn_id as id, dynasty.dyn_name')->  

$query->select(['dyn_id as id', "CONCAT(dyn_name,'a')"])->  

$query->select('user_id')->distinct()->  

FORM

$query->from('user');  

$query->from(['public.user u', 'public.post p']);  

$query->from('public.user u, public.post p');  

$query->from(['u' => 'public.user', 'p' => 'public.post']);  

----------  

$subQuery = (new Query())->select('id')->from('user')->where('status=1');  

// SELECT * FROM (SELECT `id` FROM `user` WHERE status=1) u   

$query->from(['u' => $subQuery]);  

WHERE

where('status=1')->  

where('status=:status', [':status' => $status])->  

where([  

    'status' => 10,  

    'type' => null,  

    'id' => [4, 8, 15],  

])->  

-------  

$userQuery = (new Query())->select('id')->from('user');  

// ...WHERE `id` IN (SELECT `id` FROM `user`)  

$query->...->where(['id' => $userQuery])->...  

--------  

['and', 'id=1', 'id=2'] //id=1 AND id=2  

['and', 'type=1', ['or', 'id=1', 'id=2']] //type=1 AND (id=1 OR id=2)  

['between', 'id', 1, 10] //id BETWEEN 1 AND 10  

['not between', 'id', 1, 10] //not id BETWEEN 1 AND 10  

['in', 'id', [1, 2, 3]] //id IN (1, 2, 3)  

['not in', 'id', [1, 2, 3]] //not id IN (1, 2, 3)  

['like', 'name', 'tester'] //name LIKE '%tester%'  

['like', 'name', ['test', 'sample']] //name LIKE '%test%' AND name LIKE '%sample%'  

['not like', 'name', ['or', 'test', 'sample']] //not name LIKE '%test%' OR not name LIKE '%sample%'  

['exists','id', $userQuery] //EXISTS (sub-query) | not exists  

['>', 'age', 10] //age>10  

ADD WHERE

$status = 10;  

$search = 'yii';  

$query->where(['status' => $status]);  

if (!empty($search)) {  

    $query->andWhere(['like', 'title', $search]);  

}  

//WHERE (`status` = 10) AND (`title` LIKE '%yii%')  

//andWhere() or orWhere()  

FILTER WHERE

$query->filterWhere([  

    'username' => $username,  

    'email' => $email,  

]);  

//如果email为空,则 WHERE username=:username  

ORDER BY

$query->orderBy([  

    'id' => SORT_ASC,  

    'name' => SORT_DESC,  

]);  

//orderBy , addOrderBy  

GROUP BY

$query->groupBy('id, status');  

$query->addGroupBy(['created_at', 'updated_at']);  

HAVING 

$query->having(['status' => $status]);  

//having,andHaving,orHaving  

LIMIT OR OFFSET

$query->limit(10);  

$query->offset(10);  

JOIN

  • innerJoin()
  • leftJoin()
  • rightJoin()

$query->select(['user.name AS author', 'post.title as title'])  

    ->from('user')  

    ->leftJoin('post', 'post.user_id = user.id');  

$query->join('FULL OUTER JOIN', 'post', 'post.user_id = user.id');  

$query->leftJoin(['u' => $subQuery], 'u.id=author_id');  

UNION

$query = new Query();  

$query->select("id, category_id as type, name")->from('post')->limit(10);  

$anotherQuery = new Query();  

$anotherQuery->select('id, type, name')->from('user')->limit(10);  

$query->union($anotherQuery);  

QUERY METHODS

  • all() //所有行列
  • one() //第一行
  • column() //第一列
  • scalar() //第一行第一列
  • exists() //是否有结果存在
  • count() //记录数量
  • sum($q), average($q), max($q), min($q) //$q 为字段或表达式

$count = (new \yii\db\Query())  

    ->from('user')  

    ->where(['last_name' => 'Smith'])  

    ->count();  

//SELECT COUNT(*) FROM `user` WHERE `last_name`=:last_name  

  

  

$command = (new \yii\db\Query())  

    ->select(['id', 'email'])  

    ->from('user')  

    ->where(['last_name' => 'Smith'])  

    ->limit(10)  

    ->createCommand();  

      

// show the SQL statement  

echo $command->sql;  

// show the parameters to be bound  

print_r($command->params);  

  

  

// returns all rows of the query result  

$rows = $command->queryAll();  

QUERY RESULTS

use yii\db\Query;  

$query = (new Query())  

    ->from('user')  

    ->indexBy('username');  

foreach ($query->batch() as $users) {  

    // $users is indexed by the "username" column  

}  

foreach ($query->each() as $username => $user) {  

}  

INDEXING

use yii\db\Query;  

$query = (new Query())  

    ->from('user')  

    ->orderBy('id');  

foreach ($query->batch() as $users) {  

    // batch( $batchSize = 100, $db = null )  

    // 一个批次取100行  

}  

foreach ($query->each() as $user) {  

    // 一行一行取  

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