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Editorial Team
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Asked: 2026-05-16T03:14:11+00:00

What is the difference between FOR and AFTER in trigger definition. Any benefits of

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  1. What is the difference between FOR and AFTER in trigger definition. Any benefits of using one vs another?

  2. If I issue an update statement which updates 5 rows, does the trigger (with FOR UPDATE) fires 5 times? If it is so, is there any way to make trigger fire only once for the entire UPDATE statment (even though it updates multiple rows)

  3. Is there any chance/situation of having more than one row in “inserted” or “deleted” table at any time in a trigger life cycle. If it so, can I have a very quick sample on that?

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  1. Editorial Team

    Trigger fire once for each batch and should always be designed with that in mind. Yes if you do a multi-row update insert or delte, allthe rows will be in the inserted or deleted tables. For instance the command

    Delete table1 where state = 'CA'

    would have all the rows in the table that have a state of CA in them even if it was 10,000,000 of them. That is why trigger testing is critical and why the trigger must be designed to handle multi-row actions. A trigger that works well for one row may bring the deatabase toa screeching halt for hours if poorly designed to handle mulitple rows or could cause data integrity issues if not designed correctly to handle mulitple rows. Triggers should not rely on either cursors or loops for the most part but on set-based operations. If you are setting the contents of inserted or delted to a variable, you are almost certainly expecting one row and yor trigger will not work properly when someone does a set-based operation on it.

    SQL Server has two basic kinds of DML triggers, after triggers which happen after the record has been placed in the table. These are typically used to update some other table as well. Before triggers take the place of the insert/update/delete, they are used for special processing onthe table inserted usually. It is important to know that a before trigger will not perform the action that was sent to the table and if you still want to delete/update or insert as part of the trigger you must write that into the trigger.

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