INSERT Data From One Table Into Multiple Tables

jchapa picture jchapa · Feb 10, 2010 · Viewed 8.7k times · Source

I'm using SQL Server 2005.

I am migrating data over from a current database (single table) to a new database (normalized - many tables). In the new database, I have a base table (let's call it "BaseTable"), and multiple other tables (let's call them "DependentA", and "DependentB"). Some of the data from the old database will go to BaseTable, and some will go to the other two. BaseTable has a one-to-one relationship with both DependentA and DependentB, using the Id of them as the foreign key.

So here's my question. How should I migrate the data over? Here is a query I've been trying, which is working except for one thing: the foreign keys in BaseTable for the other two are identical, instead or having a different one each.

Begin SQL:

BEGIN TRANSACTION

DECLARE @dep1Id int

DECLARE @dep2Id int

INSERT INTO DependentA (column1, column2)
SELECT c1, c2
FROM OldDatabase.OldTable
SELECT @dep1Id = Scope_Identity()

INSERT INTO DependentB (column3, column4)
SELECT c3, c4
FROM OldDatabase.OldTable
SELECT @dep2Id = Scope_Identity()

INSERT INTO BaseTable (column5, dependentTable1Id, dependentTablr2Id)
SELECT c5, @dep1Id, @dep2Id
FROM OldDatabase.OldTable

COMMIT

Answer

Paul Creasey picture Paul Creasey · Feb 11, 2010

The problem is that @dep1Id and @dep1Id are scalar and are retaining the last value only from the two set based inserts.

Since it's a one off you should probably do it as a cursor

DECLARE CURSOR @curs FOR
SELECT c1,c2,c3,c4,c5 FROM OldDatebase

open @curs
fetch next from @curs into
@c1,@c2,@c3,@c4,@c5 --declare these!

while @@fetch_status <> 0
BEGIN

INSERT INTO DependentA (column1, column2) VALUES @c1, @c2

SELECT @dep1Id = Scope_Identity()

INSERT INTO DependentB (column3, column4) VALUES @c3, @c4 

SELECT @dep2Id = Scope_Identity()

INSERT INTO BaseTable (column5, department1Id, department2Id) @c5, @dep1Id, @dep2Id    

fetch next from @curs into
@c1,@c2,@c3,@c4,@c5
END
close @curs
deallocate @curs

My cursor syntax is probably riddled with errors, but you get the idea.