Create trigger sql server for update

Delete Trigger. Below is an example of an After Delete Trigger. Whenever a row is delete in the Customers Table, the following trigger will be executed. The following Trigger is fetching the CustomerId of the deleted record and the fetched value is inserted in the CustomerLogs table. The following screenshot displays the Log table after the above Triggers were executed. Instead Of Triggers. Below is an example of an Instead Of Delete Trigger.

Whenever anyone tries to delete a row from the Customers table the following trigger is executed. Inside the Trigger, I have added a condition that if record has CustomerId value 2 then such a record must not be deleted and an error must be raised. Also a record is inserted in the CustomerLogs table. If the CustomerId value is not 2 then a delete query is executed which deletes the record permanently and a record is inserted in the CustomerLogs table.

The following error message shown when record with CustomerId 2 is deleted. The following screenshot displays the Log table after the Instead Of Trigger is executed. Related Articles. Add Comments. Thank you for the feedback. The comment is now awaiting moderation. You will be notified via email when the author replies to your comment. Please select a comment to reply. You can add your comment about this article using the form below.

I need to create a trigger on Plays table: The members attribute of the Artist table should always equal the number of musicians who are members of the Artist. Any insertion, deletion, update in Plays triggers the changes of members attribute in Musician. But I am stuck with the update part. My understanding is when updating a table, the query creates an inserted and deleted table. I considered following situation:. I have Zero experience creating triggers.

This is my question: Is this the correct way to handle update triggers? Is this query even correct? One remark first, the having and where condition are not correct: select artistname from inserted could contain several rows.

Also, we could argue that having a specific column to count the members is not really needed since this information can be calculated at anytime. But this choice may be relevant to improve performance in your case, it's up to you. The main issue I can see if that you expect the number of band members to be stored in the bands table, which you already know it's bound to change.

If I were you, I'd simply use the Play table to find out how many members a band has. Keep in mind that you might need to keep track of "fluid" bands, where members come and leave. So you might want to add a DateFrom and DateTo column for that purpose. You can then find the accurate number of members in a band at any point in time by querying the Play table using the desired date.

The update query returned successful. Similar to the previous query, the query returned successful. This update trigger is a variation of the previous one. In this case, the trigger gets fired before the update queries are executed. It is most commonly used to track and log time of modifications in the database.

Here we discuss the introduction, syntax, parameters, examples with code implementation respectively. You may also have a look at the following articles to learn more —. Submit Next Question.