Anda dapat menggunakan klausa keluaran dengan pernyataan gabungan untuk mendapatkan pemetaan antara id sumber dan id target. Dijelaskan dalam pertanyaan ini. Menggunakan merge..output untuk mendapatkan pemetaan antara source.id dan target.id
Berikut adalah beberapa kode yang dapat Anda uji. Saya menggunakan variabel tabel bukan tabel nyata.
Siapkan data sampel:
-- @A and @B is the source tables
declare @A as table
(
id int,
FK_A_B int,
name varchar(10)
)
declare @B as table
(
id int,
visible bit
)
-- Sample data in @A and @B
insert into @B values (21, 1),(32, 0)
insert into @A values (1, 21, 'n1'),(5, 32, 'n2')
-- @C and @D is the target tables with id as identity columns
declare @C as table
(
id int identity,
FK_C_D int not null,
name varchar(10)
)
declare @D as table
(
id int identity,
visible bit
)
-- Sample data already in @C and @D
insert into @D values (1),(0)
insert into @C values (1, 'x1'),(1, 'x2'),(2, 'x3')
Salin data:
-- The @IdMap is a table that holds the mapping between
-- the @B.id and @D.id (@D.id is an identity column)
declare @IdMap table(TargetID int, SourceID int)
-- Merge from @B to @D.
merge @D as D -- Target table
using @B as B -- Source table
on 0=1 -- 0=1 means that there are no matches for merge
when not matched then
insert (visible) values(visible) -- Insert to @D
output inserted.id, B.id into @IdMap; -- Capture the newly created inserted.id and
-- map that to the source (@B.id)
-- Add rows to @C from @A with a join to
-- @IdMap to get the new id for the FK relation
insert into @C(FK_C_D, name)
select I.TargetID, A.name
from @A as A
inner join @IdMap as I
on A.FK_A_B = I.SourceID
Hasil:
select *
from @D as D
inner join @C as C
on D.id = C.FK_C_D
id visible id FK_C_D name
----------- ------- ----------- ----------- ----------
1 1 1 1 x1
1 1 2 1 x2
2 0 3 2 x3
3 1 4 3 n1
4 0 5 4 n2
Anda dapat menguji kode di sini:https://data.stackexchange.com/stackoverflow/q/101643/using-merge-to-map-source-id-to-target-id
