【问题标题】:Count from 2 fields [closed]从2个字段计数[关闭]
【发布时间】:2013-07-05 10:57:44
【问题描述】:

作为 MySQL/PHP 菜鸟,我正在努力解决以下问题:

名为“汽车”的表

名为“model”和“engine”的字段

|Modell      |engine  
===================== 
|Volvo       |2,0  
|Volvo       |2,6  
|Volvo       |2,0  
|Saab        |1,8  
|Saab        |2,1  
|Saab        |1,8  
|Saab        |1,8  
|Chevrolet   |4,2  

想写一个问题并得到答案:

这里是:

2 volvo with 2,0 engine  
1 volvo with 2,6 engine  
3 saab with 1,8 engine  
1 saab with 2,1 engine  
1 Chevrolet with 4,2 engine  

【问题讨论】:

    标签: php mysql count field


    【解决方案1】:
    SELECT count(*) AS count,
           Modell,
           engine 
    FROM cars 
    GROUP BY Modell,engine
    

    【讨论】:

      【解决方案2】:
      select modell, engine, count(*) as cnt
      from cars
      group by modell, engine
      

      【讨论】:

        【解决方案3】:

        SELECT COUNT(*),Modell,ENGINE FROM cars GROUP BY modell,ENGINE

        【讨论】:

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