For loop in php mysql pdo execute7/9/2023 ![]() Now let’s take a closer look at the basic syntax of a trigger by stripping it down to its raw form: CREATE TRIGGER TrigName ON tableName Triggers are only fired when a raw SQL statement has been executed foreign key relationship deletions, for example, will not activate a trigger.You’ll need to drop the trigger and recreate it. You are unable to explicitly alter a trigger with an ALTER statement (unlike with events).Upon table deletion, the triggers associated with it are also dropped.Only one trigger with the same event (update/insert/delete) and timing (before/after) is allowed per table.They must have unique (case-insensitive) names in the database they have been created in.Here are some other quick notes regarding triggers: Generally no shared hosting plan will allow you SUPER because of how easily it can be abused, so you may only be able to use these on a server where you have more authority, like a (virtual) dedicated server or your localhost, depending on the version of MySQL you’re using. Prior to MySQL 5.1.6, you needed the SUPER privilege, but this changed in 5.1.6, to where you’ll need the TRIGGER privilege. You’ll need to have the appropriate privileges to create triggers. They’re automatically invoked before or after an action (insert, update, delete) has been executed on a table. Triggers were introduced in MySQL version 5.0.2 and are just one of MySQL’s added functionality to help make our lives easier as developers. So, it is the intention of this article to give you some insight into the creation and usage of MySQL triggers, so that by the end of this reading you can make use of them in your own projects. It’s here where MySQL triggers came into my project.īy making MySQL do more work through triggers, the PHP side of my project was greatly simplified. This was not viable from a maintenance standpoint and was a complete nightmare when I wanted to update part of the page’s functionality. It was far from elegant, and what should have been a rather simple script had turned into a convoluted page of queries. One of my recent projects involved a rather cumbersome problem that led me to using countless queries just to make sure all of the data was up to sync throughout my tables after each action. But have you ever noticed the amount of code you are having to write out sometimes to verify some previous action? Whether it’s for database querying, file manipulation, data handling, etc., it’s all required to make our scripts function to their set purpose. Much of the code we write is to perform an action. ![]()
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