每个类别的 SQL 计数

Question

我需要根据 2 个字段来计算行数以进行分组。

动物（一）

id     group_id   strain_id     death_date     death_cause   status
-----------------------------------------------------------------------
1      512        164           2015-12-01     Culled        P
2      512        164           2015-12-02     Culled        A
3      512        164           2015-12-02     Surplus       B
4      512        230           2015-12-06     Culled        A
5      512        164           2015-12-28     Culled        A
6      512        230           2016-01-20     Culled        B
7      512        230           2016-01-20     Surplus       P
8      512        164           NULL           NULL          P
9      512        230           NULL           NULL          B
10     512        230           NULL           NULL          A
11     512        164           2016-01-25     Culled        B
12     512        164           2016-02-29     Culled        A
13     512        230           2016-02-03     Surplus       P
14     512        230           2016-02-03     Culled        A

组 (g)

id     group_name
--------------
512    Mice

应变

id     strain_name
----------------
164    Strain 1
230    Strain 2

群体动物数量 (gac)

id     total_animals      alive_count       dead_count
----------------------------------------------------------------------
512    14                 3                 11

交配历史 (mh)

id     animal_id     history_type      history_date
--------------------------------------------------------
1001   2             MA                2015-11-20
1002   2             MR                2015-12-01
1003   3             MA                2015-12-01
1004   6             FA                2015-12-21
1005   9             FA                2016-02-07
1006   10            MA                2016-01-27
1007   11            FA                2015-12-12

因此，当我将它们按 strain_id 和 death_cause 分组时，它们在视觉上应该是这样的：

菌株 1 ---- 剔除

1      512        164           2015-12-01     Culled        P
2      512        164           2015-12-02     Culled        A
5      512        164           2015-12-28     Culled        A
11     512        164           2016-01-25     Culled        B
12     512        164           2016-02-29     Culled        A

应变 1 ---- 剩余

3      512        164           2015-12-02     Surplus       B

菌株 2 ---- 剔除

4      512        230           2015-12-06     Culled        A
6      512        230           2016-01-20     Culled        B
14     512        230           2016-02-03     Culled        A

应变 2 ---- 剩余

7      512        230           2016-01-20     Surplus       P
13     512        230           2016-02-03     Surplus       P

我想从 SQL 查询中得到以下结果：

g_name  s_name    d_cause  a_total  c_alive  c_dead  c_pup  c_breeder  c_total
------------------------------------------------------------------------------
Mice    Strain 1  Culled   12       3        9       1      2          5
Mice    Strain 1  Surplus  12       3        9       0      1          1
Mice    Strain 2  Culled   12       3        9       0      1          3
Mice    Strain 2  Surplus  12       3        9       2      0          2

基本上我想使用 2 个类别来计算动物的数量，在这种情况下是 strain_name 和 death_cause

请注意，对于要算作饲养员 (c_breeder) 的动物，我必须查看交配历史表并检查 animal_id 是否曾有任何这些代码 MA 或 FA .

我在groups、group_animal_count 和strains 上使用INNER JOIN。我将LEFT JOIN 用于mating_history，因为状态为P 的动物在该表中不会有记录，因为它们只是幼崽，不会参与交配。

Answer 1

试试：

SELECT group_name, strain_name,death_cause, count(*) as Total
FROM ANIMALS a
JOIN GROUPS g ON a.group_id = g.id
JOIN STRAIN s ON a.strain_id = s.id
GROUP BY group_name, strain_name,death_cause

Answer 2

您可以在加入表格之前进行聚合：

SELECT group_name, strain_name, death_cause, total
FROM   (
         SELECT   group_id,
                  strain_id,
                  death_cause,
                  COUNT(*) AS total
         FROM     animals
         GROUP BY group_id, strain_id, death_cause
       ) a
       INNER JOIN groups g ON ( g.group_id = a.group_id )
       INNER JOIN strain s ON ( s.strain_id = a.strain_id );