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8 lut 2021 · ON DELETE CASCADE constraint is used in MySQL to delete the rows from the child table automatically, when the rows from the parent table are deleted. For example when a student registers in an online learning platform, then all the details of the student are recorded with their unique number/id.
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20 cze 2013 · ON DELETE CASCADE: if a row of the referenced table is deleted, then all matching rows in the referencing table are deleted. ON DELETE SET NULL: if a row of the referenced table is deleted, then all referencing columns in all matching rows of the referencing table to be set to null.
As you want to modify the FK constraint by adding ON DELETE/UPDATE CASCADE, follow these steps: NUMBER 1: Right click on the constraint and click to Modify. NUMBER 2: Choose your constraint on the left side (if there are more than one).
This tutorial shows you how to use MySQL ON DELETE CASCADE to automatically delete data from a child table when you delete data from the parent table.
16 sie 2023 · The ON DELETE CASCADE feature in SQL allows you to delete child rows when a parent row is deleted. Learn all about it in this guide.
The MySQL ON DELETE CASCADE constraint ensures that when a row in the parent table is deleted, all related rows in the child table are automatically deleted as well. This constraint helps maintain referential integrity between two tables that are connected through a foreign key relationship.
19 mar 2024 · Two critical options that can be applied to foreign key constraints are ON DELETE CASCADE and ON UPDATE CASCADE. These options automate the maintenance of referential integrity between tables, but it's important to understand how they work and when they should be used.
