sql - INSERT deleted values into a table before DELETE with a DELETE TRIGGER

Question

For some reason I can't find the exact answer that I need. I searched for at last 20 minutes in here.

I know it's simple. VERY simple. But I can't fire the trigger for some reason..

I have a table with two columns

dbo.HashTags

|__Id_|_name_|
|  1  | Love |

I want to insert the deleted values into another table called dbo.HashTagsArchive on a DELETE query.

Example:

DELETE FROM [dbo].[HashTags] WHERE Id=1

After this example I should have the deleted row in dbo.HashTagsArchive and the row with Id=1 should be deleted in dbo.HashTags

I tried this TRIGGER:

ALTER TRIGGER [dbo].[HashTags_BeforeDelete]
    ON [dbo].[HashTags]
    FOR DELETE
AS
  BEGIN
    INSERT INTO HashTagsArchive
   ( Id,
     HashTagId,
     delete_date)
   SELECT d.Id, m.HashTagId,GETUTCDATE() FROM deleted d 
   JOIN dbo.HashTags m ON m.Id=d.Id
    DELETE FROM dbo.HashTags
    WHERE ID IN(SELECT deleted.Id FROM deleted)
  END
GO

It's getting Deleted but no Inserted row in the HashTagsArchive

Answer 1

Your problem is: this trigger fires AFTER the delete has already happened. So there is no more row in HashTags which you could join on!

You need to use this trigger instead:

ALTER TRIGGER [dbo].[HashTags_BeforeDelete]
    ON [dbo].[HashTags]
    FOR DELETE
AS
  BEGIN
    INSERT INTO HashTagsArchive(Id, HashTagId, delete_date)
       SELECT 
           d.Id, d.HashTagId, GETUTCDATE() 
       FROM deleted d 
  END
GO

The Deleted pseudo table contains the whole row(s) that were deleted - no need to join on anything...

Also: this trigger fires after the delete has happened - so you don't need to do anything yourself, inside the trigger - just insert those bits of information into your archive table - that's all. Everything else is handled by SQL Server for you.