How and when to use SLEEP() correctly in MySQL?
Solution 1:
SELECT ...
SELECT SLEEP(5);
SELECT ...
But what are you using this for? Are you trying to circumvent/reinvent mutexes or transactions?
Solution 2:
If you don't want to SELECT SLEEP(1);, you can also DO SLEEP(1); It's useful for those situations in procedures where you don't want to see output.
e.g.
SELECT ...
DO SLEEP(5);
SELECT ...