How Can I Efficiently Update Multiple MySQL Tables with a Single Query?

Efficiently update multiple MySQL tables using a single query

In database management, it is often necessary to update data in multiple tables at the same time. Although it is possible to use separate queries to update each table, this has disadvantages in terms of efficiency and maintainability. MySQL provides a solution to update multiple tables using a single query.

This feature is particularly useful when updates involve related tables and data integrity needs to be maintained. To perform a multi-table update, the syntax consists of an UPDATE statement, followed by a comma-separated list of table names.

For example, consider the following scenario:

• Two tables: Books and Orders
• Requirements: Increase the quantity of books in the order (OrderID = 1002) and accordingly decrease the quantity of inventory available in the Books table.

The following query demonstrates how to complete this update in one step:

<code class="language-sql">UPDATE Books, Orders
SET Orders.Quantity = Orders.Quantity + 2,
    Books.InStock = Books.InStock - 2
WHERE
    Books.BookID = Orders.BookID
    AND Orders.OrderID = 1002;</code>

This query efficiently performs two updates at once, maintaining the desired relationship between increasing order quantity and decreasing book inventory. Use this feature to improve code readability, reduce query complexity, and ensure data consistency.

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