Question

我有一张如下表格

No. FName Age  Tag
1    abc   22    c
2    xyz   60    c
3    pqr   62    i
4    abc   22    i
5    abc   32    i

我希望将结果作为

返回

No. FName Age  Tag
1    abc   22    c
2    xyz   60    c
3    pqr   62    i
5    abc   32    i

要求是，如果Name行的列Age AND 列tag=c and tag=i值相同，则tag=i行应< strong>不被选中。

行号1和行号。 4具有相同的值(Name,age)=(abc,22)但行4具有tag = i。因此，必须省略(abc,22,i)之上的第4行。我怎么能这样做？

Answer 1

WITH records
AS
(
    SELECT  No, FName, Age, Tag,
            ROW_NUMBER() OVER (PARTITION BY FName, Age
                                ORDER BY Tag ASC) rn
    FROM    tableName
    WHERE   TAG IN ('c','i')
)
SELECT  No, FName, Age, Tag
FROM    records
WHERE   rn = 1

SQLFiddle Demo

如果您在TAG上有其他特殊值，

WITH records
AS
(
    SELECT  No, FName, Age, Tag,
            ROW_NUMBER() OVER (PARTITION BY FName, Age
                                ORDER BY CASE WHEN TAG = 'c' THEN 0 ELSE 1 END ASC) rn
    FROM    tableName
    WHERE   TAG IN ('c','i')
)
SELECT  No, FName, Age, Tag
FROM    records
WHERE   rn = 1
ORDER   BY No

SQLFiddle Demo

更新1

SELECT Fname, Age, MIN(tag) Tag
FROM   TableName
WHERE  TAG IN ('c','i')
GROUP  BY Fname, Age

SQLFiddle Demo

Answer 2

我认为如果已经存在具有相同tag，age和name ='c'的行，则可以忽略tag ='i'的所有行：

select * from TableName t1
where not exists 
          (select 1 
           from TableName 
           where FNAme = t1.FNAme and Age = t1.Age and t1.Tag = 'i' and tag = 'c')

如果列值与先前行不同，请选择行

2 个答案: