特定的SQL查询AVG和计数

Question

我的数据库中有以下表格

我需要一个选择查询才能获得：

1. 每个A的总持续时间，其中Type = 1 ... type = 2 ... type = 3
2. 每种类型的计数（A）（其中type-1 ... type = 2且type = 3

所以我的结果是这样的：

类型2计数类型2 AVG（持续时间）类型1 AVG（持续时间）类型2

1029 20 15 200 156

获得上述结果的确切查询是什么？

Answer 1

这就是你在找什么：

SELECT DISTINCT a,
       SUM(CASE WHEN type = 1 THEN 1 ELSE 0 END) OVER (PARTITION BY a) AS count_of_type_1,
       SUM(CASE WHEN type = 2 THEN 1 ELSE 0 END) OVER (PARTITION BY a) AS count_of_type_2,
       SUM(CASE WHEN type = 3 THEN 1 ELSE 0 END) OVER (PARTITION BY a) AS count_of_type_3,
       AVG(CASE WHEN type = 1 THEN duratuion ELSE 0 END) OVER (PARTITION BY a) AS avg_duration_of_type_1,
       AVG(CASE WHEN type = 2 THEN duratuion ELSE 0 END) OVER (PARTITION BY a) AS avg_duration_of_type_2,
       AVG(CASE WHEN type = 3 THEN duratuion ELSE 0 END) OVER (PARTITION BY a) AS avg_duration_of_type_3,
       SUM(CASE WHEN type = 1 THEN duratuion ELSE 0 END) OVER (PARTITION BY a) AS total_duration_of_type_1,
       SUM(CASE WHEN type = 2 THEN duratuion ELSE 0 END) OVER (PARTITION BY a) AS total_duration_of_type_2,
       SUM(CASE WHEN type = 3 THEN duratuion ELSE 0 END) OVER (PARTITION BY a) AS total_duration_of_type_3
FROM your_table