Question

我需要使用cakephp从数据库中的每个类别中提取3个结果，我尝试使用mysql会话变量和条件在数据库中查询，如下所示

    SELECT *, @question_cat_rank := 0, @question_cat_country:=''
   FROM
     (SELECT *, 
                  @question_cat_rank := IF(@question_cat_country = question_setname.question_cat, @question_cat_rank + 1, 1) AS question_cat_rank,
                  @question_cat_country := question_cat 
       FROM question_setname
        ORDER BY question_cat desc
     ) ranked
   WHERE question_cat_rank <= 3

它在mysql查询分析器中工作正常，但是当我使用cakephp查询时，它返回所有结果表中的3个结果

我尝试使用像下面的cakephp方式创建它

public $virtualFields = array(
                '@catvirt' => 1,
                '@catvirt2' => 'question_cat',
                'incrmt' => 'IF(@catvirt2 = question_cat, @catvirt+1, 1)',
            );
        function getquestionGroup(){

            $result1 = $this->find('all', array(
                'fields' => array('question_cat', '@catvirt2', 'incrmt'),
                '@catvirt2'=> 'question_cat',
                '@catvirt' => '@catvirt'
                    )
                  );

            $result = $this->find('all', array($result1,
                'conditions' => array('@catvirt <=' => 3), 
                    )
                  );

我试图执行准备好的语句和存储过程仍然没有运气它返回所有结果

任何帮助将不胜感激

Answer 1

我会这样写这个查询：

 SELECT x.* 
   FROM           
      ( SELECT *                                             
             , @question_cat_rank := IF(@question_cat_country = question_cat, @question_cat_rank + 1, 1) question_cat_rank
             , @question_cat_country := question_cat 
          FROM question_setname 
             , (SELECT @question_cat_rank := 0, @question_cat_country:='') vars
         ORDER 
            BY question_cat DESC
      ) x
  WHERE question_cat_rank <= 3;

cakephp group by n结果为每组

1 个答案: