Question

我正在尝试一次从结果集中提取一条记录，以用作在表中插入数据的Select语句中的值。

select [Id] 
from TBL 
where PId = '123' 
order by value

结果集1

查询2：

select [Id] 
from TBL 
where PId = '456' 
order by value

结果集2

最后，我尝试通过从Result-set1和Result-set2中获取值来将数据插入表中。

insert into TBL ([Val], [Disp], [Seq], [Active], [DId], [PId])
    select [Val], [Disp], [Seq], [Active], 'One Record From Result-set1', '1111' 
    from TBL 
    where PId = '2222' 
      and DId = 'One Record From Result-set2'

我读到游标有助于一次从结果集中提取一条记录，但是我不确定如何在我的场景中实现它。

insert into TBL ([Val], [Disp], [Seq], [Active], [DId], [PId])
    select [Val], [Disp], [Seq], [Active], '222', '1111' 
    from TBL 
    where PId = '2222' 
      and DId = '666'

我试图摆脱硬编码222和666。

Answer 1

假设两个查询都返回相同数量的记录（这是一个很大的假设），则可以使用使用行号创建的ID将两个数据集连接起来。然后，您可以使用笛卡尔积将表中的记录插入到查询返回的结果中。

insert into TBL ([Val], [Disp], [Seq], [Active], [DId], [PId])
select [Val], [Disp], [Seq], [Active], cj.Id1, '1111' 
from TBL 
  cross join (
    select rs1.[Id] Id1, rs2.[Id] Id2
    from (    
      select 
        row_number() over (partition by (select null) order by value) rn,
        [Id] 
      from TBL where PId = '123'
    ) rs1
    join (
      select 
        row_number() over (partition by (select null) order by value) rn,
        [Id] 
      from TBL where PId = '456'
    ) rs2
  on rs1.rn=rs2.rn
  ) cj
where PId = '2222' 
  and DId = cj.Id2

使用光标选择或在表中插入数据

1 个答案: