Question

我有4张桌子，

A，B，C，D

A有列Aid， B有列Aid， C有列Aid， D有列Aid

（援助是所有4个表中的共同栏目）

现在我想从A表中获取B或C或D中不存在的行任何人都可以让我知道SQL查询。

Answer 1

准备示例数据：

CREATE TABLE A (aid int);
CREATE TABLE B (aid int);
CREATE TABLE C (aid int);
CREATE TABLE D (aid int);
INSERT INTO A VALUES (1);
INSERT INTO A VALUES (2);
INSERT INTO A VALUES (3);
INSERT INTO A VALUES (4);
INSERT INTO A VALUES (5);
INSERT INTO B VALUES (2);
INSERT INTO C VALUES (3);
INSERT INTO D VALUES (4);

查询：

SELECT aid
FROM A
LEFT OUTER JOIN B on A.aid=B.aid
LEFT OUTER JOIN C on A.aid=C.aid
LEFT OUTER JOIN D on A.aid=D.aid
WHERE B.aid IS NULL AND C.aid IS NULL AND D.aid IS NULL;

结果为1和5。

Answer 2

您可以使用MINUS运算符：

SELECT Aid FROM A
MINUS
SELECT Aid FROM B
MINUS
SELECT Aid FROM C
MINUS
SELECT Aid FROM D

示例

CREATE TABLE A ( Aid, Value ) AS SELECT 1, '1' FROM DUAL UNION ALL SELECT 1, '2' FROM DUAL UNION ALL SELECT 2, '3' FROM DUAL UNION ALL SELECT NULL, '4' FROM DUAL UNION ALL SELECT 3, '5' FROM DUAL; CREATE TABLE B ( Aid, BValue ) AS SELECT 1, '3' FROM DUAL; CREATE TABLE C ( Aid, CValue ) AS SELECT 4, '7' FROM DUAL; CREATE TABLE D ( Aid, DValue ) AS SELECT NULL, '9' FROM DUAL;

<强>查询：

SELECT Aid FROM A MINUS SELECT Aid FROM B MINUS SELECT Aid FROM C MINUS SELECT Aid FROM D

<强>输出：

AID --- 2 3

更新以获取A 的所有列：

这将排除Aid相等或两者都为NULL的行：

SELECT * FROM A WHERE NOT EXISTS(SELECT 1 FROM B WHERE A.Aid = B.Aid OR (A.Aid IS NULL AND B.Aid IS NULL)) AND NOT EXISTS(SELECT 1 FROM C WHERE A.Aid = C.Aid OR (A.Aid IS NULL AND C.Aid IS NULL)) AND NOT EXISTS(SELECT 1 FROM D WHERE A.Aid = D.Aid OR (A.Aid IS NULL AND D.Aid IS NULL));

Answer 3

SELECT A.aid FROM A WHERE NOT EXISTS (select 1 from B where B.aid = A.aid) AND NOT EXISTS (select 1 from C where C.aid = A.aid) AND NOT EXISTS (select 1 from D where D.aid = A.aid)

Answer 4

请使用以下查询，它将完美运作。

select *  from #A  where  Aid  not in (select Aid   From #B
    UNION
    select Aid   From #C
    Union
    select Aid   From #D)

Answer 5

使用NOT IN运算符

Select * from A
Where Aid not in (
  Select Aid from B
  Union all
  Select Aid from C
  Union all
  Select Aid from D
)

ert that ..如果表A中援助无效，但B，C＆amp; D没有null， null将不会被返回。在这种情况下，左连接是优越的... - JGFMK 43分钟前

如果表A在aid列中包含NULL，则左连接查询将始终返回该行，而不管其他表中是否会出现NULL。请检查这个简单的测试用例http://rextester.com/ESZWH45744

SQL查询从一个表中获取其他3个表中不存在的行

5 个答案: