我想复制第三列和第四列,但更改第二列。我该怎么办?我想知道如何编写sql查询。谢谢。
例如:
table1:
1, 1, aaa, bbb
2, 1, ads, bff
3, 1, awq, bcc我希望table1最终成为:
1, 1, aaa, bbb
2, 1, ads, bff
3, 1, awq, bcc
4, 2, aaa, bbb
5, 2, ads, bff
6, 2, awq, bcc(第一列是id)
发布于 2017-08-04 14:54:10
这应该是可行的:
insert into table1 (column2,column3,column4)
select 2,column3, column4
from table1 where column2 = 1 发布于 2017-08-04 14:50:16
按照您的建议:
select (@cnt:=@cnt + 1) as RowNumber,a.c1,a.c2,a.c3 from
(select 1 as id, 1 as c1, 'aaa' as c2, 'bbb'as c3 union all
select 2, 1, 'ads', 'bff' union all
select 3, 1, 'awq', 'bcc'
union all
select 1 as id, 1 as c1, 'aaa' as c2, 'bbb'as c3 union all
select 2, 1, 'ads', 'bff' union all
select 3, 1, 'awq', 'bcc') as a
cross JOIN
(select @cnt:=0) as tmp结果:
1 1 aaa bbb
2 1 ads bff
3 1 awq bcc
4 1 aaa bbb
5 1 ads bff
6 1 awq bcchttps://stackoverflow.com/questions/45499711
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