MySql update two tables at once

Question

I have two tables that need the exact same values for denormalization purposes.

Here\'s the query.

first table

UPDATE Table_One 
SET win = win+1         


        

Answer 1

If there is a one to one or one to many relation from Table_One to Table_Two, this would work:

UPDATE Table_One T1, Table_Two T2 
SET T1.win = T1.win+1, T1.streak = T1.streak+1, T1.score = T1.score+200, 
    T2.win = T2.win+1, T2.streak = T2.streak+1, T2.score = T2.score+200 
WHERE T1.userid = 1 AND T1.lid = 1 AND T2.userid = T1.userid;

Answer 2

They’re two separate queries and so must be treated as such. Sorry to say it, but if you’re updating two tables with identical data, there’s probably a better way to design your database. Remember to keep your programming DRY.

Edit: Should retract that; you can use it for multiple tables, but you can’t use ORDER BY or LIMIT.

Answer 3

It should be possible with a multi-table update, as described in the documentation.

http://dev.mysql.com/doc/refman/5.5/en/update.html

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

Note: Multi-table doesn't support LIMIT, so this could cause more grief depending on the details.

Stored procedures or transactions may be a nicer solution.

Answer 4

If you can join the tables, then you could create a view of two tables, then update via that view. In your example it looks like userid might be a suitable key.

In creating the view, you'd need to stick to the following guidelines.