Trigger is a rule that constitutes a set of T-SQL statements activated in response to a certain actions such as insert or delete. Trigger are used to ensure data integrity before or after performing data manipulation.




A BEFORE UPDATE Trigger means that MySQL will fire this trigger before the UPDATE operation is executed.


The syntax to create a BEFORE UPDATE Trigger in MySQL is:

Parameters or Arguments

OR REPLACE: It is an optional parameter. It is used to re-create the trigger if it already exists. It facilitates you to change the trigger definition without using a DROP TRIGGER statement.

trigger_name : name of the trigger to create.

BEFORE UPDATE: indicates that the trigger will fire before the UPDATE operation is executed.

table_name: name of the table that the trigger is created on.


  • You can not create a BEFORE trigger on a view.
  • You can update the NEW values.
  • You can not update the OLD values.


Let’s look at an example of how to create an BEFORE UPDATE trigger using the CREATE TRIGGER statement in MySQL.

If you had a table created as follows:

We could then use the CREATE TRIGGER statement to create an BEFORE UPDATE trigger as follows:



Rasmi Ranjan

A tech guy who loves to learn code. I'm open source enthusiast and a delicious coffee maker

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