带计数/分组的mySQL查询

我有以下数据：

ID   user    value     lang
------------------------------
1    1       foo1      de
2    1       foo2      de
3    1       bar1      en
4    1       bar2      en
5    1       bar3      en
6    1       bar4      fr

期望输出：

user   de    en    fr 
------------------------------
1      2     3     1

我想从用户1获取所有语言的总数

---

我试过使用

COUNT

、

SUM

和

HAVING

。。但它不起作用。

您可以使用条件聚合

SELECT user,
       SUM(CASE WHEN lang='de' THEN 1 ELSE 0 END) as 'de',
       SUM(CASE WHEN lang='en' THEN 1 ELSE 0 END) as 'en',
       SUM(CASE WHEN lang='fr' THEN 1 ELSE 0 END) as 'fr'
  FROM t
 GROUP BY user

或直接无条件：

SELECT user,
       SUM(lang='de') as 'de',
       SUM(lang='en') as 'en',
       SUM(lang='fr') as 'fr'
  FROM t
 GROUP BY user

---

您可以使用条件聚合

SELECT user,
       SUM(CASE WHEN lang='de' THEN 1 ELSE 0 END) as 'de',
       SUM(CASE WHEN lang='en' THEN 1 ELSE 0 END) as 'en',
       SUM(CASE WHEN lang='fr' THEN 1 ELSE 0 END) as 'fr'
  FROM t
 GROUP BY user

或直接无条件：

SELECT user,
       SUM(lang='de') as 'de',
       SUM(lang='en') as 'en',
       SUM(lang='fr') as 'fr'
  FROM t
 GROUP BY user

---

您可以添加您尝试过的内容吗？您是否按分组？是否可以添加您尝试过的内容？您是否按分组？