mysql - 通过组合三个不同的sql查询的数据得到公共数据

Question

SELECT STATNO FROM ENQUIRY  WHERE ID=12;

回报：100,102,110

SELECT STATNO FROM ENQUIRY  WHERE ID=16;

回报：102,112,118

 SELECT STATNO FROM ENQUIRY  WHERE ID=21;

回报：101,102,120

我需要一个结合上述内容并返回公共数据的查询：102。

Answer 1

You can use JOIN in your query:

SELECT a.STATNO FROM ENQUIRY a
JOIN (
   SELECT x.STATNO FROM ENQUIRY x WHERE ID=16
) b ON a.STATNO = b.STATNO
JOIN (
   SELECT y.STATNO FROM ENQUIRY y WHERE ID=21
) c ON b.STATNO = c.STATNO
 WHERE a.ID=12

Answer 2

drop table if exists enquiry;
create table enquiry (id integer, statno integer);
insert into enquiry values 
(12,100),(12,102),(12,110),
(18,102),(18,112),(18,118),
(21,101),(21,102),(21,120);

select distinct statno from enquiry where 
statno in (select statno from enquiry where id=12)
and statno in (select statno from enquiry where id=18)
and statno in (select statno from enquiry where id=21)
;

Answer 3

Unfortunately INTERSECT doesnt work with MySQL. You could do this instead..

SELECT     a.STATNO
FROM       ENQUIRY AS a 
INNER JOIN ENQUIRY AS b ON b.STATNO = a.STATNO 
INNER JOIN ENQUIRY AS c on c.STATNO = a.STATNO 
WHERE a.id = 12 and b.id = 16 and c.id =21

Answer 4

嗨，您可以使用 group by 和有声明

SELECT STATNO FROM ENQUIRY  WHERE ID IN (12 ,16 , 21) group by STATNO having count(*)  = 3;

这种方法只有在combination of (ID, STATNO) is unique. 在这里count(*) would be equal to total number of values in IN statement in query like here is 3。

谢谢