Selecting last 5 entries

Anon

How would I go about selecting the last 5 entries from a table in mysql?

I know I can use "select * from [table] LIMIT 5;" to select the first 5, but how would I go about selecting the last 5?

I have tried doing using the 2 parameter option for "LIMIT" (ie, LIMIT [last entry] -5, [last entry]) but I need to select the last 5 entries that match another search spec as well (WHERE example=whatever).

Please help.

Anon

select * from my_table order by some_condition desc limit 5;

Now, that <i>order by</i> is going to be computationally
expensive if there's not an index on <i>some_condition</i>.
Note, too, that your original query is doing less than you
think it is (though perhaps you just simplified it too much
for presentation here.) Saying 'select * from there limit 5'
does indeed give you the first 5 rows, but it gives them
from an unspecified ordering. If you interpret the sql
spec literally, it wouldn't be wrong for your server to
give you a different group of 5 each time you make
that query, and in real life if your dbms is efficient
about reusing deleted row space, you're quite likely
to see it happen from that cause.

Anon

I'll have to agree with Kirk. Just because you put data into the database in some order, that doesn't mean it stays in that order over time. If you store a date or id column, you can ORDER BY column DESC like kirk said, and then apply the limit 5. That's your best bet. Without that ORDER BY the "last 5" is ambigious....or however you spell it.

Repeating what Kirk said, I guess... 🙂

---JH

Anon

I had a similar query, where i wanted to display the last 10 entries, my database contains a timestamp field.

however, whilst test this query, i used the ID field to order the database.::

select * from table_name order by ID;

when i pressed enter, the Mysql crashed. And i am running it under Win98 and I got a popup box with words to the effect "test signal" and a OK button.

Why does this happen???

Light on this matter greatly appreciated.

THanks,

Vikesh.