Does MySQL wait for last UPDATE to finish before continuing

Question

I used an UPDATE to update a table, then my next SELECT statement did not seem to pick up all the changes done in that last UPDATE. I was wondering if the last UPDATE was still working while my SELECT command was being processed.

When I ran the SELECT command again afterwards, it all worked fine, and it picked up all the changed records. It was as though the UPDATE needed time to finish, and the commands were being processed asyncronasly.

Answer 1

If it is on InnoDB engine, this depends on the transaction type, but often update is not visible to OTHER connections until it was committed. So, if you create some new process and it selects what other process did not commit yet then it will not see it.