Question

我如何才能实现某些字段的区别，并且返回结果集包括所有列？

下面是sql查询：

       SELECT DISTINCT FIELD1,FIELD2,FIELD3,FIELD4,FIELD5
       FROM T1
       RESULT COUNT - 5000
       Observation - it is distinct for all five fields as DISTINCT APPLIED ON WHOLE RECORD.
                      BUt, FIELD1, FIELD2,FIELD43 are just duplicated and vary only FIELD 4, AND field5

另一个sql查询（刚跳过最后两列）。

       SELECT DISTINCT FIELD1,FIELD2,FIELD3     --SKIPPED FIELD4,FIELD5
       FROM T1
       RESULT COUNT - 3000 
      OBVESERVATION - it shows only distinct record for all three field.

问题：我只需要三个字段的不同记录（FIELD1，FIELD2，FIELD3），它应该包括 - FIELD4，FIELD5

如何实现。

谢谢

Answer 1

您希望为FIELD4和FIELD5返回什么，具有相同FIELD1-3的任何行的数据？

select *
from
 (
   SELECT FIELD1,FIELD2,FIELD3,FIELD4,FIELD5,
      ROW_NUMBER()
      OVER (PARTITION BY FIELD1,FIELD2,FIELD3
            ORDER BY FIELD4) as rn
   FROM T1
 ) as dt
where rn = 1;

或者只是来自任何一行的任何数据？

SELECT FIELD1,FIELD2,FIELD3,MIN(FIELD4),MIN(FIELD5)
FROM T1
GROUP BY FIELD1,FIELD2,FIELD3

但是这可能会从两个不同的行返回MIN，因此实际上没有行。

如何在某些字段上应用DISTINCT sql查询并返回所有列？

1 个答案: