SQL Server A trigger to work on multiple row inserts

Question

I am maintaining some code that has a trigger on a table to increment a column. That column is then used by a 3rd party application A. Lets say that the table is ca

Answer 1

Take a look at inserted pseudo table in your trigger as it will contain multiple rows during these operations. You should always handle multiple rows in your triggers anyway.

See here for more info:

How to test for multiple row actions in a SQL Server trigger?

Answer 2

You just have to open a cursor on INSERTED and iterate it for @PROC_NEWNUM1 and put your rest of code that loop. e.g

 DECLARE @PROC_NEWNUM1 VARCHAR (10)
 DECLARE @NEWNUM2 numeric(20)
 DECLARE my_Cursor CURSOR FOR SELECT num1 FROM INSERTED; 
 OPEN my_Cursor; 

 FETCH NEXT FROM @PROC_NEWNUM1; 


 WHILE @@FETCH_STATUS = 0 
 BEGIN FETCH NEXT FROM my_Cursor 
 select @NEWNUM2 = MAX(num2) from TEST
 if @NEWNUM2 is null
 Begin
  set  @NEWNUM2  = 0
 end
 set @NEWNUM2 = @NEWNUM2 + 1
 UPDATE TEST SET num2 = @NEWNUM2 WHERE num1 = @PROC_NEWNUM1

 END; 

CLOSE my_Cursor; DEALLOCATE my_Cursor;

Answer 3

Trigger needs to be rewriteen to handle multiple row inserts. Never write a trigger like that using variables. All triggers must alawys consider that someday someone is going to do a multi-row insert/update/delete.

You shouldn't be incrementing columns that way in a trigger either, if you need incremented column numbers why aren't you using an identity column?