How to Efficiently Delete Records from Multiple MySQL Tables?

Multi-Table Record Deletion in MySQL

Deleting records from multiple MySQL tables concurrently often leads to syntax errors. This guide provides effective solutions:

Leveraging JOIN in DELETE Statements

To remove entries from both pets and pets_activities tables where the order exceeds a given value and pet_id matches, utilize a JOIN:

<code class="language-sql">DELETE p, pa
FROM pets p
JOIN pets_activities pa ON pa.id = p.pet_id
WHERE p.order > :order
AND p.pet_id = :pet_id</code>

This efficiently deletes matching records across both tables.

Specifying Target Tables

Alternatively, explicitly define the table for deletion using aliases:

<code class="language-sql">DELETE pa
FROM pets_activities pa
JOIN pets p ON pa.id = p.pet_id
WHERE p.order > :order
AND p.pet_id = :pet_id</code>

This example only deletes from pets_activities.

Key Considerations

• Besides JOIN, subqueries or cascading deletes offer alternative approaches for multi-table deletions.
• Method selection depends on your database schema and desired results.
• Using JOIN helps preserve referential integrity during cross-table deletions.

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