Question

我有一张大表包含20,000条记录。我想找到类似的记录（那些BNO和BNO-CSCcode列上的重复记录）

   CSCcode   Description   BNO        BNO-CSCcode     EID

    05078     blah1        5430      5430-05078       1098
    05026     blah2        5431      5431-05026       1077
    05026     blah3        5431      5431-05026       3011
    04020     blah4        8580      8580-04020       3000
    07620     blah5        7560      7560-07620       7890
    07620     blah6        7560      7560-07620       8560
    05020     blah1        5560      5560-04020       1056
    01234    sampledesc    0009      0009-01234       1156
    04567    sampledesc2   0056      0056-04567       1656
    01234    sampledesc8   0009      0009-01234       0023

我想要检索

    CSCcode   Description   BNO        BNO-CSCcode     EID

    05026     blah2        5431      5431-05026       1077
    05026     blah3        5431      5431-05026       3011
    07620     blah5        7560      7560-07620       7890
    07620     blah6        7560      7560-07620       8560
    01234    sampledesc    0009      0009-01234       1156
    01234    sampledesc8   0009      0009-01234       0023

如何在sql查询中指定。

Answer 1

select t1.* 
from table_name t1
inner join (select BNO,BNO-CSCcode 
           from table_name
           group BNO,BNO-CSCcode
           having count(1)>1) as t2
on t1.BNO=t2.BNO and t1.BNO-CSCcode=t2.BNO-CSCcode

Answer 2

  select field1,field2,field3, count(*)
  from table_name
  group by field1,field2,field3
  having count(*) > 1

Answer 3

使用HAVING：

select *
from mytable 
where bno & bno_csccode in
(
  select bno & bno_csccode
  from mytable
  group by bno, bno_csccode
  having count(*) > 1
);

Answer 4

您必须在查询中使用EXISTS命令。

这将提供所需的结果：

SELECT *
FROM TableName t0
WHERE EXISTS (
    SELECT 1
    FROM TableName t1
    WHERE t0.BNO = t1.BNO AND t0.BNOCSC = t1.BNOCSC
    GROUP BY BNO, BNOCSC
    HAVING count(*) > 1
    )

EXISTS用于比较一个或多个列。

如何在两列中查找重复项访问sql

4 个答案: