Question

我有两个sql server 2005表，如下所示：

Table A
varName  varStatus
AGE      Text
AGENDA   Text
TEACH    Text


Table B
varName   varDesc
ACT       Text
AGE       Text
SAT       Text
GPA       Text

我需要一个或两个查询来获取两个表中不在两个表中的所有varNames。例如，上面的示例将使用：

Table A:  AGENDA, TEACH
Table B: ACT, SAT, GPA

这是正确的，因为AGE是两个表中唯一出现的varname。

Answer 1

此查询将为您提供A中的所有记录，但不包括B

SELECT A.* FROM 
A LEFT JOIN B ON A.varName = B.varName
WHERE B.varName IS NULL

同样，此查询将为您提供B中的记录，但不会在A

中

SELECT B.* FROM 
A RIGHT JOIN B ON A.varName = B.varName
WHERE A.varName IS NULL

最后，你需要做的只是联合两个查询

SELECT A.* FROM 
A LEFT JOIN B ON A.varName = B.varName
WHERE B.varName IS NULL
UNION
SELECT B.* FROM 
A RIGHT JOIN B ON A.varName = B.varName
WHERE A.varName IS NULL

Answer 2

如果变量可以在单个列表中，请使用UNION和NOT IN

SELECT 'A' AS sourceTable, varName
FROM   tableA
WHERE  varName NOT IN (SELECT varName FROM tableB)
UNION ALL
SELECT 'B' AS sourceTable, varName
FROM   tableB
WHERE  varName NOT IN (SELECT varName FROM tableA)

Answer 3

(SELECT varName FROM tableA EXCEPT SELECT varName FROM tableB)
UNION
(SELECT varName FROM tableB EXCEPT SELECT varName FROM tableA)

在2个表之间获取排除变量

3 个答案: