Question

I have three tables in my database. A users table, StoreA and StoreB

StoreA and StoreB both have a unique key which is the user ID value.

What I want is; When I create a user and insert them into the database, how can I Insert a row into the other two tables without too many additional queries.

I figure I can do this by inserting the user in one query,
then in another return the newly created user ID,
then in another, using said ID, create rows in StoreA and StoreB

Can I cut out the middle query?

Answer 1

Can I cut out the middle query?

YES

START TRANSACTION;
INSERT INTO user (id, name, other) 
          VALUES (null, 'John','rest of data');
INSERT INTO storeA (id, user_id, other) 
            VALUES (null, @user_id:= LAST_INSERT_ID(), 'rest of data');
INSERT INTO storeB (id, user_id, other) 
            VALUES (null, @user_id, 'rest of data');
COMMIT;

See: http://dev.mysql.com/doc/refman/5.0/en/getting-unique-id.html

It’s a good idea to do this in a transaction, you you’re not stuck with just a user with no other data if something goes wrong.
It’s not a DB requirement though.