How to add foreign key constraints in phpmyadmin

Steps to add foreign key constraints in phpMyAdmin: Prepare foreign keys and main table. Right-click the foreign key table and select Design View. Find the foreign key field and switch to the "Select Properties" tab. Check the "Foreign Key" checkbox and select the main table and main field. save Changes.

How to add foreign key constraints in phpMyAdmin

Step 1: Prepare foreign keys and main table

Before adding foreign key constraints, you need to ensure that the foreign key table and the main table have been created in the database.

Step 2: Right-click the foreign key table

In phpMyAdmin, find the foreign key table to which you want to add a foreign key constraint. Right-click the table name and select Design View.

Step 3: Find the foreign key field

In Design View, find the field that you want to be the foreign key. It is usually a field of the same type as the field in the main table.

Step 4: Configure foreign key constraints

Under the "Select Properties" tab of the field, find the "Foreign Key Constraints" section. Select the Foreign Key checkbox and select the following options:

• Primary table: Select the primary table to which the foreign key field relates.
• Main field: Select the main field corresponding to the foreign key field in the main table.

Step 5: Save changes

After configuring the foreign key constraints, click the "Save" button.

Description:

• Adding foreign key constraints helps ensure data integrity and prevents foreign key tables from appearing when records are deleted or updated in the main table Isolated records.
• The fields in the main table must be unique indexes or primary keys before they can be used as reference fields for foreign keys.
• Deleting records in the main table will cascade delete all related records in the foreign key table (if foreign key constraints are set).

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