Question

ID  TXT  PID
12  A    13
13  B    15
15  C    Null

需要编写一个srpoc，它会将此源数据插入到其中包含标识列的目标表中

ID   TXT  PID
1    A    2
2    B    3
3    C    Null

在目标表中，ID是标识列，PID是ID列的外键。

以下是我尝试使用tmp表的方法。但我得到的结果不是实际结果。请帮帮我。

ID  TXT  PID
1    A    1
2    B    2
3    C    Null


drop table #tmp

Create table #tmp
(
id int identity (1,1) constraint pk_tab Primary key,
Txt varchar(10),
ParentId int NULL
        CONSTRAINT FK_Categories_ParentId
        FOREIGN KEY (id) REFERENCES #tmp
)

insert into #tmp(Txt)
Select Source.s from 
(Select f.ID,f.T as s,g.T as p from
(select 12 as ID, 'A' as T, 13 as PID
union all
Select 13,'B',15
union all
select 15,'C',null
) f
left join 
(select 12 as ID, 'A' as T, 13 as PID
union all
Select 13,'B',15
union all
select 15,'C',null
)g
on f.ID = g.PID
) Source

Select * from #tmp

update #tmp 
SET
    #tmp.ParentId = #tmp.ID
FROM
    #tmp
INNER JOIN
    (Select f.ID,f.T as s,g.T as p from
(select 12 as ID, 'A' as T, 13 as PID
union all
Select 13,'B',15
union all
select 15,'C',null
) f
left join 
(select 12 as ID, 'A' as T, 13 as PID
union all
Select 13,'B',15
union all
select 15,'C',null
)g
on f.ID = g.PID
) Source
ON
    #tmp.Txt = Source.p

Select * from #tmp

Answer 1

我不明白如何禁止额外的列。除非这是家庭作业/工作面试/谜题，否则您只需更改代码：

Create table #tmp
(
id int identity (1,1) constraint pk_tab Primary key,
Txt varchar(10),
ParentId int NULL,
OriginalId int NULL
        CONSTRAINT FK_Categories_ParentId
        FOREIGN KEY (id) REFERENCES #tmp
)

SQL：将层次结构从源复制到具有标识列的目标

1 个答案: