mysql find smallest + unique id available

Question

i have a column ID and something like 1000 items, some of then were removed like id=90, id=127, id=326

how can i make a query to look for those availabl

Answer 1

It's against the concept of surrogate keys to try to reuse IDs

The surrogate key is good because it idetifies the record itself, not some object in real life. If the record is gone, the ID is gone too.

Experienced DB developers are not afraid of running out of numbers because they know how many centuries it is needed to deplete, say, long integer numbers.

BTW, you may experience locking or violating uniqueness problems in a multithreaded environment with simultaneous transactions trying to find a gap in the ID sequence. The auto increment id generators provided by DB servers usually work outside the transactions scope and thus generate good surrogate keys.

Further reading: Surrogate keys