Add values to a table based on values in another table

When a record is inserted or updated records in Table1 I want a record to be inserted into table3 for each record ID that is in table2 if the table2.id does not already exist in table3. What is the best way to do this? Could this be done with a trigger? If it could how would I write such a trigger. I have never written one before and this sounds like a hand full for my first effort. Your help will be greatly appreciated.

Thanks

You could do it in a trigger. They're really not hard. It's just SQL you want to run whenever a certain action happens on your table. Pretty straightforward. Another option is to use stored procedures to do all of your inserts and updates. Then, just code what could go in the trigger directly into your stored procedure.

Pete

Add ID at Insert

The below code works fine, but for one reason, I need to get the ReferenceID inserted into a seperate table along with the newly created unique ID in the table Box. Any ideas how I can accomplish this...

CREATE PROCEDURE AddBox
(
@.BoxNumber nvarchar(40),
@.LocId int,
@.BoxNotes Text,
--This gets added to a different table that I'll call References, but can't go until I can get the uniqueID of what is inserted.
@.ReferenceID int
)
AS
INSERT INTO box
(
box_num,
loc_id,
box_notes,
status_id
)
VALUES
(
@.BoxNumber,
@.Locid,
@.BoxNotes,
2
)

didnt quite understand your question but check out BOL for SCOPE_IDENTITY().

hth|||Just the point in the right direction I needed, Thanks.

Once I inserted a new box file into the Box table I then was able to get the Unique ID number and then insert that into a reference table. The end code (after the first insert) for my previous post ends up looking as such:

Set @.Identity = SCOPE_IDENTITY()
Set @.Reference = @.ReferenceNumber
Insert into reference
(
reference_name,
box_id
)
VALUES
(
 @.Reference,
 @.Identity
)
GO