Hi David,

There're a few reasons to use a table alias in a query. It's required if you use the same table more than once in a query. It could be a correlated subquery (like below) or a query that uses self-join on a table. You don't have to but may use an alias in multi-table query or/and query with long table names so query will be shorter and more readable. The key is to use short but easy recognizable aliases, not a, b, c, e.t.c.

You can use < pre > and < /pre > tags (w/o spaces) to preseve code formatting. You should be able to see it if you've auto-quote turned on and hit reply on my message.

>Hi Sergey,
>
>One question about the solution you posted; I had not used an alias in a select comand before. Is there a benefit for using aliases (ie. ST1) in Select comands, or was this for clarification?

>    SELECT st1.date, st1.name, ;
>		st1.status_id, st1.stats_id, st1.lots_id ;
>	FROM status st1 ;
>	WHERE st1.stats_id = event1val ;
>		AND NOT EXISTS (SELECT * FROM status st2 ;
>			WHERE st1.lots_id = st2.lots_id ;
>				AND st2.stats_id = event2val)

>
>Also (way off topic), how do you get your code to show with a different background color when posting to the thread?
>
>Thanks again Sergey.
>
>David