So I was looking at row locking for innoDB and it seems like SELECT...FOR UPDATE is the go to query for locking. In my file I have three queries. Two updates and then an insertion. Is there a way to make sure that for each connection the rows are locked and then these three queries can run before someone else can change the rows?
Here are the queries:
"UPDATE table SET r=r+2 WHERE r > '$l' AND home='$home'";
"UPDATE table SET l=l+2 WHERE l > '$l' AND home='$home'";
"INSERT INTO table (value, home, l, r, value2)
VALUES ('$value', '$home', '$l'+1, '$l'+2, value2) ";
To clarify: I want to lock all the rows where home=$home and then free them after the three queries. I want to make sure the three queries are executed before any other connections can have write abilities to those rows.
Use transactions, your changes are not visible to others until you commit them explicitly.
Further informations: msql docs on transactions