Query Builder

1. 1 $rows = (new \yii\db\Query())
   2     ->select([‘dyn_id‘, ‘dyn_name‘])
   3     ->from(‘zs_dynasty‘)
   4     ->where([‘between‘,‘dyn_id‘, 1,30])
   5     ->limit(10)
   6     ->all();
   7 print_r($rows);  

   1 use yii\db\Query;
   2 $query = (new Query())
   3     ->from(‘user‘)
   4     ->orderBy(‘id‘);  

SELECT

1 $query->select(‘*‘)->
2     select(‘dyn_id as id, dynasty.dyn_name‘)->
3     $query->select([‘dyn_id as id‘, "CONCAT(dyn_name,‘a‘)"])->
4     $query->select(‘user_id‘)->distinct()->  

FORM

 1 $query->from(‘user‘);
 2 $query->from([‘public.user u‘, ‘public.post p‘]);
 3 $query->from(‘public.user u, public.post p‘);
 4 $query->from([‘u‘ => ‘public.user‘, ‘p‘ => ‘public.post‘]);
 5
 6
 7 $subQuery = (new Query())->select(‘id‘)->from(‘user‘)-
 8     >where(‘status=1‘);
 9 // SELECT * FROM (SELECT `id` FROM `user` WHERE status=1) u
10 $query->from([‘u‘ => $subQuery]);  

WHERE

 1 where(‘status=1‘)->
 2 where(‘status=:status‘, [‘:status‘ => $status])->
 3 where([
 4     ‘status‘ => 10,
 5     ‘type‘ => null,
 6     ‘id‘ => [4, 8, 15],
 7 ])->
 8 -------
 9 $userQuery = (new Query())->select(‘id‘)->from(‘user‘);
10 // ...WHERE `id` IN (SELECT `id` FROM `user`)
11 $query->...->where([‘id‘ => $userQuery])->...
12 --------
13 [‘and‘, ‘id=1‘, ‘id=2‘] //id=1 AND id=2
14 [‘and‘, ‘type=1‘, [‘or‘, ‘id=1‘, ‘id=2‘]] //type=1 AND (id=1 OR id=2)
15 [‘between‘, ‘id‘, 1, 10] //id BETWEEN 1 AND 10
16 [‘not between‘, ‘id‘, 1, 10] //not id BETWEEN 1 AND 10
17 [‘in‘, ‘id‘, [1, 2, 3]] //id IN (1, 2, 3)
18 [‘not in‘, ‘id‘, [1, 2, 3]] //not id IN (1, 2, 3)
19 [‘like‘, ‘name‘, ‘tester‘] //name LIKE ‘%tester%‘
20 [‘like‘, ‘name‘, [‘test‘, ‘sample‘]] //name LIKE ‘%test%‘ AND name LIKE ‘%sample%‘
21 [‘not like‘, ‘name‘, [‘or‘, ‘test‘, ‘sample‘]] //not name LIKE ‘%test%‘ OR not name LIKE ‘%sample%‘
22 [‘exists‘,‘id‘, $userQuery] //EXISTS (sub-query) | not exists
23 [‘>‘, ‘age‘, 10] //age>10  

ADD WHERE

1 $status = 10;
2 $search = ‘yii‘;
3 $query->where([‘status‘ => $status]);
4 if (!empty($search)) {
5     $query->andWhere([‘like‘, ‘title‘, $search]);
6 }
7 //WHERE (`status` = 10) AND (`title` LIKE ‘%yii%‘)
8 //andWhere() or orWhere()  

FILTER WHERE

1. $query->filterWhere([
       ‘username‘ => $username,
       ‘email‘ => $email,
   ]);
   //如果email为空,则 WHERE username=:username  

ORDER BY

1 $query->orderBy([
2     ‘id‘ => SORT_ASC,
3     ‘name‘ => SORT_DESC,
4 ]);
5 //orderBy , addOrderBy  

GROUP BY

1 $query->groupBy(‘id, status‘);
2 $query->addGroupBy([‘created_at‘, ‘updated_at‘]);  

HAVING 

1 $query->having([‘status‘ => $status]);
2 //having,andHaving,orHaving  

LIMIT OR OFFSET

1 $query->limit(10);
2 $query->offset(10);  

JOIN

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

1 $query->select([‘user.name AS author‘, ‘post.title as title‘])
2     ->from(‘user‘)
3     ->leftJoin(‘post‘, ‘post.user_id = user.id‘);
4 $query->join(‘FULL OUTER JOIN‘, ‘post‘, ‘post.user_id = user.id‘);
5 $query->leftJoin([‘u‘ => $subQuery], ‘u.id=author_id‘);  

UNION

1 $query = new Query();
2 $query->select("id, category_id as type, name")->from(‘post‘)->limit(10);
3 $anotherQuery = new Query();
4 $anotherQuery->select(‘id, type, name‘)->from(‘user‘)->limit(10);
5 $query->union($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

 1 $count = (new \yii\db\Query())
 2     ->from(‘user‘)
 3     ->where([‘last_name‘ => ‘Smith‘])
 4     ->count();
 5 //SELECT COUNT(*) FROM `user` WHERE `last_name`=:last_name
 6
 7
 8 $command = (new \yii\db\Query())
 9     ->select([‘id‘, ‘email‘])
10     ->from(‘user‘)
11     ->where([‘last_name‘ => ‘Smith‘])
12     ->limit(10)
13     ->createCommand();
14
15 // show the SQL statement
16 echo $command->sql;
17 // show the parameters to be bound
18 print_r($command->params);
19
20
21 // returns all rows of the query result
22 $rows = $command->queryAll();  

QUERY RESULTS

1 use yii\db\Query;
2 $query = (new Query())
3     ->from(‘user‘)
4     ->indexBy(‘username‘);
5 foreach ($query->batch() as $users) {
6     // $users is indexed by the "username" column
7 }
8 foreach ($query->each() as $username => $user) {
9 }  

INDEXING

 1 use yii\db\Query;
 2 $query = (new Query())
 3     ->from(‘user‘)
 4     ->orderBy(‘id‘);
 5 foreach ($query->batch() as $users) {
 6     // batch( $batchSize = 100, $db = null )
 7     // 一个批次取100行
 8 }
 9 foreach ($query->each() as $user) {
10     // 一行一行取
11 }