I need to select the last(latest) row in a table, what's the query going to look like. Do I need to first count how many rows, then use the number in a select query? This seems ineffficient to me.
"latest" makes sense only in the context of MAX(some_datetime_column)
does your table gots something like that?
No, by latest i just mean the very last row.
unfortunately, there is no such concept
rows in database tables do not have a position
everything must be accomplished by reference to column values
You are kinda right, i found what i was looking for is just a simple:
select * from table order by id desc limit 1
the reference is to the id column - like you said
that'll work (most of the time)
may i ask why you need to query out the latest row?
i need to query the latest row so i can use the values obtained
in the next row - a kinda "balance carried over" thing, i'm working
on a ledger system.
that could get you in trouble
the "latest" row might not be for the same account
do a search on race condition
you're probably going to want to use transactions
Fortunately, it's not going to be a multi-user system,
it's an offline software developed with php/mysql accessed
only by the admin.