Question

我现在对SQL查询不太了解，我有一个问题

SELECT PERSON_REF 
FROM   IMAGES 
WHERE  PERSON_REF IN (SELECT _PERSON_ID 
                      FROM   PERSONS 
                      WHERE  REGION_REF = (SELECT _REGION_ID 
                                           FROM   REGIONS 
                                           WHERE  REGION_ABB = "EU")) 
GROUP  BY PERSON_REF 
HAVING Count(PERSON_REF) >= 3

此查询提供的结果如

现在我想在其他查询中使用该结果，如何做到这一点，我是否需要创建循环或是否有其他方式

SELECT PERSON_REF 
FROM   IMAGES 
WHERE  EFFECT_REF = 2 
       AND PERSON_REF IN ( 2, 4, 5, 6 )

Answer 1

select Person_Ref from Images  where Person_Ref IN ( 
Select _Person_ID from Persons where
Region_Ref in (select _Region_ID from Regions where Region_Abb = "EU"))
and EFFECT_REF = 2 
group by Person_Ref HAVING COUNT(Person_Ref) >= 3

Answer 2

试试这个：

select Person_Ref from Images where Effect_Ref = 2 and Person_Ref IN 
( your first query which gives 2 4 5 6)

Answer 3

试试这个：

SELECT PERSON_REF 
FROM   IMAGES 
WHERE  EFFECT_REF = 2 
       AND PERSON_REF IN (SELECT PERSON_REF 
                          FROM   IMAGES 
                          WHERE  PERSON_REF IN (SELECT _PERSON_ID 
                                                FROM   PERSONS 
                                                WHERE 
                                 REGION_REF = (SELECT _REGION_ID 
                                               FROM   REGIONS 
                                               WHERE 
                                 REGION_ABB = "EU")) 
                          GROUP  BY PERSON_REF 
                          HAVING Count(PERSON_REF) >= 3)

Answer 4

JOIN三个表Images，Persons和Regions而不是这些IN和子查询：

 SELECT i.Person_Ref 
 FROM Images i
 INNER JOIN Persons p ON i.Person_Ref = p.Person_Ref
 INNER JOIN Regions r ON p.Region_Ref = r.Region_Ref
 WHERE r.Region_Abb = "EU"
   AND i.Effect_Ref = 2 
 GROUP BY i.Person_Ref 
 HAVING COUNT(i.Person_Ref) >= 3

Answer 5

有几种方法可以做到这一点。您可以使用IN示例，因为它已经是无法使用但只有在您只需要一列时才会起作用（我知道，这是您的情况，但如果您遇到需要更多的情况，最好知道可以做什么oncolumn）

简单的方法是将你的查询包装到parentesys并给它一个别名，这样你就可以像使用它一样使用它：

(SELECT PERSON_REF 
FROM   IMAGES 
WHERE  PERSON_REF IN (SELECT _PERSON_ID 
                      FROM   PERSONS 
                      WHERE  REGION_REF = (SELECT _REGION_ID 
                                           FROM   REGIONS 
                                           WHERE  REGION_ABB = "EU")) 
GROUP  BY PERSON_REF 
HAVING Count(PERSON_REF) >= 3 ) MY_ALIAS

然后你可以加入你的其他查询。这通常不是一个好方法。

最好的apporach，它使用公用表格式（CTE），所以你会做这样的事情：

with MY_FIRST_QUERY as(
SELECT PERSON_REF 
    FROM   IMAGES 
    WHERE  PERSON_REF IN (SELECT _PERSON_ID 
                          FROM   PERSONS 
                          WHERE  REGION_REF = (SELECT _REGION_ID 
                                               FROM   REGIONS 
                                               WHERE  REGION_ABB = "EU")) 
    GROUP  BY PERSON_REF 
    HAVING Count(PERSON_REF) >= 3 
)
select MY_FIRST_QUERY.PERSON_REF

并且无论你需要什么，你就加入它

Answer 6

只需将AND添加到第一个谓词并指定另一个谓词。

SELECT PERSON_REF 从图像 WHERE PERSON_REF IN（SELECT _PERSON_ID 来自人 WHERE REGION_REF =（SELECT _REGION_ID 来自地区 REGERE_ABB =“EU”））和 EFFECT_REF = 2 GROUP BY PERSON_REF 有计数（PERSON_REF）＆gt; = 3

将一个SQL查询的结果添加到另一个查询

6 个答案: