如何从数据库查询 [英] How to query from database

问题描述

嗨伙计



我想获得未满18岁的记录



我有两张桌子家庭，成员



家庭：

< td> 4

id	name
1	Famliy1
2	Famliy2
3	Famliy3
Famliy4

成员：





< tr height =20>

id	fid	name	年龄
1	1	AAAAA	11
2	1	BBBBB	19
3	1	CCCCC	14
4	2	DDDDD	18
5	2	EEEEEE	29
6	2	FFFFFF	23
7	3	GGGGG	13
8	3	HHHHH	14
9	3	IIIIII	16
10	4	JJJJJJ	22
11	4	KKKKK	24
12	4	LLLLLL	25

I想得到家庭没有18岁以下成员的名字

解决方案

尝试：

  SELECT  m.id，m.name，f.name，m.Age 
  FROM 成员m 
 < span class =code-keyword> JOIN 族f  ON  m.fid = f.id 
 在哪里 m.Age>  17  

ok我想在会员表中获取最后三个记录，因为他们没有18岁以下的成员



您的数据不会这样做：FID 2有没有18岁以下的成员。

但是试试这个：

  SELECT  m。 id，m.name，f.name，m.Age  FROM 成员m 
  JOIN （  SELECT  Fid  FROM 成员 GROUP   BY  Fid  HAVING  MIN（AGE）>  17 ） j 
  ON  j.Fid = m.FID 
  JOIN 家庭f  ON  m.Fid = f.Id 

要获得最后三行，您需要排除18岁以及：

  SELECT  m.id，m.name，f.name，m.Age  FROM 成员m 
  JOIN （ SELECT  Fid  FROM 成员 GROUP   BY  Fid  HAVING  MIN（AGE）>  18 ）j 
  ON  j.Fid = m.FID 
  JOIN 族f  ON  m.Fid = f.Id 

试试这个：

  SELECT  
 F.id，
 F.name 
  FROM  
 family  As  F 
  WHERE  
 不 存在 
 （
  SELECT   1  
  FROM 成员作为 M 
  WHERE  M.fid = F.id 
 和 M.Age<  18  
）
; 

hi guys

I want to get records that haven't Age under 18

I have two tables family, members

family:

id	name
1	Famliy1
2	Famliy2
3	Famliy3
4	Famliy4

members:

id	fid	name	Age
1	1	AAAAA	11
2	1	BBBBB	19
3	1	CCCCC	14
4	2	DDDDD	18
5	2	EEEEEE	29
6	2	FFFFFF	23
7	3	GGGGG	13
8	3	HHHHH	14
9	3	IIIIII	16
10	4	JJJJJJ	22
11	4	KKKKK	24
12	4	LLLLLL	25

I want to get family name that haven't member under 18

解决方案

Try:

SELECT m.id, m.name, f.name, m.Age
FROM Members m
JOIN Family f ON m.fid = f.id
WHERE m.Age > 17

ok I want to get the last three records in members table because they haven't members under 18

Your data doesn't do that: FID 2 has no members under 18.
But try this:

SELECT m.id, m.name, f.name, m.Age FROM Members m
JOIN (SELECT Fid FROM Members GROUP BY Fid HAVING MIN(AGE) > 17) j
ON j.Fid = m.FID
JOIN Family f ON m.Fid = f.Id

To get just the last three rows, you need to exclude 18 year olds as well:

SELECT m.id, m.name, f.name, m.Age FROM Members m
JOIN (SELECT Fid FROM Members GROUP BY Fid HAVING MIN(AGE) > 18) j
ON j.Fid = m.FID
JOIN Family f ON m.Fid = f.Id

Try this:

SELECT
    F.id,
    F.name
FROM
    family As F
WHERE
    Not Exists
    (
        SELECT 1
        FROM Members As M
        WHERE M.fid = F.id
        And M.Age < 18
    )
;

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