编写1个SQL查询，将3个独立的表与函数组合在一起：GROUPBY和case when_Sql

编写1个SQL查询，将3个独立的表与函数组合在一起：GROUPBY和case when

sql

编写1个SQL查询，将3个独立的表与函数组合在一起：GROUPBY和case when,sql,Sql,我有以下三个表格：表a有4列： date: (2020-11-31,...) note: (20, 30, 40,...) home: (23.45, 45.34, 65.67, ...) id: (54326, 87332, ...) time: (2020-11-31,...) grade: (34, 54, 34,...) homework: (12.32, 34.65,...) user: ('student', 'professor', 'stude

我有以下三个表格：

表a有4列：

date: (2020-11-31,...)  
note: (20, 30, 40,...)  
home: (23.45, 45.34, 65.67, ...)  
id: (54326, 87332, ...)

time: (2020-11-31,...)  
grade: (34, 54, 34,...)   
homework: (12.32, 34.65,...)   
user: ('student', 'professor', 'student',...)

day:  (2020-11-31,...)  
number: (34, 54, 34,...)  
amount: (10.24 AGE, 11.25 AGE, 12.63 AGE, ...)    
title: ('54934-ST-string-student-str.st', '54934-ST-string-teacher-str.st',....)

表b有4列：

date: (2020-11-31,...)  
note: (20, 30, 40,...)  
home: (23.45, 45.34, 65.67, ...)  
id: (54326, 87332, ...)

time: (2020-11-31,...)  
grade: (34, 54, 34,...)   
homework: (12.32, 34.65,...)   
user: ('student', 'professor', 'student',...)

day:  (2020-11-31,...)  
number: (34, 54, 34,...)  
amount: (10.24 AGE, 11.25 AGE, 12.63 AGE, ...)    
title: ('54934-ST-string-student-str.st', '54934-ST-string-teacher-str.st',....)

表c有4列：

date: (2020-11-31,...)  
note: (20, 30, 40,...)  
home: (23.45, 45.34, 65.67, ...)  
id: (54326, 87332, ...)

time: (2020-11-31,...)  
grade: (34, 54, 34,...)   
homework: (12.32, 34.65,...)   
user: ('student', 'professor', 'student',...)

day:  (2020-11-31,...)  
number: (34, 54, 34,...)  
amount: (10.24 AGE, 11.25 AGE, 12.63 AGE, ...)    
title: ('54934-ST-string-student-str.st', '54934-ST-string-teacher-str.st',....)

很抱歉，表格演示文稿，但以表格格式放置并不容易

我创建了一个SQL查询来计算每个表所需的内容，但我没有成功地将这3个查询合并到一个表中。我想不出我需要用什么逻辑来组合它

以下是每个表的SQL代码：

SELECT 
    SUM(home/note) AS kpi,   
    CASE     
       WHEN id IN (34564, 87423, 89076, 32145, 87653) THEN 'Student'     
       WHEN id IN (67543, 87413, 78996, 34215 ) THEN 'Teacher'     
       ELSE 'Other'      
    END AS role   
FROM school_a     
WHERE date >= '2020-08-01' AND date <= '2020-08-31'    
GROUP BY role     

SELECT 
    SUM(grade)/COUNT(user) AS kpi,    
    CASE     
       WHEN user = 'Student' THEN 'Student'     
       WHEN user = 'Professor' THEN 'Teacher'        
       ELSE 'Other'      
    END AS role     
FROM school_b      
WHERE time >= '2020-08-01' AND time <= '2020-08-31'    
GROUP BY role     


SELECT 
    SUM((REPLACE(amount,' AGE',''))/number) AS kpi,   
    CASE     
       WHEN title IN ('41320 - ST-STtr-Student-str.st', '89064 - ST-stRst-str-strr user-strr.str/blablabla/strstr') THEN 'Student'   
       WHEN title IN ('43789 - ST-STred-Teacher-stee.str', '65283-CH-strstrs-teacher-strr.str--STR') THEN 'Teacher'     
       ELSE 'Other'     
    END AS role    
FROM school_c     
WHERE day >= '2020-08-01' AND day <= '2020-08-31'    
GROUP BY role

选择
作为关键绩效指标的金额（主值/注释），
案例
当id为（3456487423890763214587653）时，则为“学生”
当id为（67543、87413、78996、34215）时，则为“教师”
“其他”
以角色结束
来自学校
其中日期>='2020-08-01'和日期='2020-08-01'以及时间='2020-08-01'和日期您是否尝试简单地合并不同的输出
SELECT SUM(home/note) AS kpi,   
CASE     
WHEN id IN (34564, 87423, 89076, 32145, 87653) THEN 'Student'     
WHEN id IN (67543, 87413, 78996, 34215 ) THEN 'Teacher'     
ELSE 'Other'      
END AS role   
FROM school_a     
WHERE date >= '2020-08-01' AND date <= '2020-08-31'    
GROUP BY role     

UNION

SELECT SUM(grade)/COUNT(user) AS kpi,    
CASE     
WHEN user = 'Student' THEN 'Student'     
WHEN user = 'Professor' THEN 'Teacher'     
ELSE 'Other'      
END AS role     
FROM school_b      
WHERE time >= '2020-08-01' AND time <= '2020-08-31'    
GROUP BY role     

UNION

SELECT SUM((REPLACE(amount,' AGE',''))/number) AS kpi,   
CASE     
WHEN title IN ('41320 - ST-STtr-Student-str.st', '89064 - ST-stRst-str-strr user-strr.str/blablabla/strstr') THEN 'Student'   
WHEN title IN ('43789 - ST-STred-Teacher-stee.str', '65283-CH-strstrs-teacher-strr.str--STR') THEN 'Teacher'     
ELSE 'Other'     
END AS role    
FROM school_c     
WHERE day >= '2020-08-01' AND day <= '2020-08-31'    
GROUP BY role   

选择总和（主/备注）作为kpi，
案例
当id为（3456487423890763214587653）时，则为“学生”
当id为（67543、87413、78996、34215）时，则为“教师”
“其他”
以角色结束
来自学校
其中日期>='2020-08-01'和日期='2020-08-01'和时间='2020-08-01'和日期什么是“联合”？请提供样品输出这是我第一次提出这样的问题。感谢各位撰稿人让我的问题更具可读性。您使用的“合并”查询是什么？因为我认为你可以简单地联合所有人
，因为每个表只有[kpi][role]两列。注意总和（等级）/计数（用户）
可以替换为平均（等级）
（假设用户
永远不能为空）我编辑了我的问题@astentx我想在一个sql查询中运行我在问题中编写的3个查询。预期结果是两列，每个角色有3行和相应的kpi。我几乎得到了预期的结果。我有两列角色（学生、教师、其他）和每个角色的kpi。结果是每所学校：a学校/b学校/c学校。如果我想在不考虑学校分组的情况下按角色分组，我该怎么办？你知道我需要在哪里添加更改才能只按角色分组，而不再按学校分组吗@thommy@Isa只需从该联合中选择，并执行分组方式
@Isa，如其他注释所述。只需从联合输出中选择，并在联合之外执行分组方式<代码>按输出选择*从（此处为联合）作为输出组。角色