How can I Update Multiple Tables Simultaneously in MySQL?

Updating Multiple Tables Simultaneously in MySQL

When working with relational databases, it may be necessary to update related data across multiple tables simultaneously. This poses a challenge if standard update statements are used, as they can only modify one table at a time.

Consider the following scenario, where two tables (Table_One and Table_Two) require the same updates for denormalization purposes. While the update queries for each table are nearly identical, they differ in table name and field availability.

Separate Updates

Traditionally, these updates would be executed separately:

UPDATE Table_One SET win = win+1, streak = streak+1, score = score+200 WHERE userid = 1 AND lid = 1 LIMIT 1;
UPDATE Table_Two SET win = win+1, streak = streak+1, score = score+200 WHERE userid = 1 LIMIT 1;

Multi-Table Updates

However, MySQL offers a more efficient solution with multi-table updates. By joining the tables on a common field (in this case, "userid"), it is possible to update both tables with a single query:

UPDATE Table_One a INNER JOIN Table_Two b ON (a.userid = b.userid)
SET
  a.win = a.win+1, a.streak = a.streak+1, a.score = a.score+200,
  b.win = b.win+1, b.streak = b.streak+1, b.score = b.score+200
WHERE a.userid = 1 AND a.lid = 1 AND b.userid = 1;

It is important to note that multi-table updates do not support the LIMIT clause, which may cause unintended updates if not used carefully. Alternative solutions, such as stored procedures or transactions, may be more appropriate in certain scenarios.

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