mysql - MySQL按子句计算分组中的多列

Question

我想计算在 group by 子句中使用的每个不同的组。我现在正在使用这个查询：

SELECT language, group,  count(*) AS frequency
FROM bfs
where firstname <> ''
GROUP BY language, group

这给了我这样的结果：

'Language' 'Group'                'Frequency' 
'ARABIC'   'LEBANESE'               1080 
'ARABIC'   'MUSLIM'                40963 
'ARABIC'   'MUSLIM MIDDLE EAST'      349 
'ARABIC'   'MUSLIM  NORTH AFRICAN'   549 

我想要的是：而不是每种语言和组列组合的总频率，我想知道每种语言和组属性的记录有多少

'Language' 'Group' 'Frequency' 'Language Frequency' 'Group Frequency'
'ARABIC'   'LEBANESE' 1080        42941              1080 

其中 Language Frequency 表示以 'ARABIC' 为值的总行数；同样，组频率表示包含“LEBANESE”作为组频率的总行数。任何帮助将不胜感激。

谢谢！

Answer 1

SELECT 
    g.language, g.`group`, g.frequency,
    gl.language_frequency, gg.group_frequency
FROM
      ( SELECT language, `group`,  COUNT(*) AS frequency
        FROM bfs
        WHERE firstname > ''
        GROUP BY language, `group`
      ) AS g
    JOIN
      ( SELECT language, COUNT(*) AS languageFrequency
        FROM bfs
        WHERE firstname > ''
        GROUP BY language
      ) AS gl
      ON gl.language = g.language
    JOIN
      ( SELECT `group`, COUNT(*) AS group_frequency
        FROM bfs
        WHERE firstname > ''
        GROUP BY `group`
      ) AS gg
      ON gg.`group`= g.`group` ;