help in getting results from mysql
| From: | Christian Dechery | Date: | Tue, 03 Jul 2001 00:24:56 +0000 |
| Subject: | help in getting results from mysql | ||
| Groups: | php.general | ||
| Request: | Send a blank email to php-general+get-55915@lists.php.net to get a copy of this message | ||
I have to get some results from a mysql table, and I'm pretty sure that I'm not doing it the best way.
its like this... I have a table (a historical one) with these fields:
date | item_id | item_type_id | qty | value
and there are multiple lines for the pair item/type (as I said it's a historical table). I want the row with the last date.
So if I had:
2001-29-6 | 34 | 3 | 5 | 15.0
2001-30-6 | 34 | 3 | 7 | 13.0
2001-1-7 | 34 | 3 | 9 | 12.0
2001-2-7 | 34 | 3 | 1 | 3.5
I only want the last one '2001-2-7'. But I can't think of a way of doing this without sub-select. So I did this:
<pre>
$rs1=mysql_query("select max(date) from tablename where item_id=34 and item_type_id=3");
$last_date=mysql_result($rs1,0,0);
$rs2=mysql_query("select qty,value from tablename where date='$last_date'");
list($qty,$value) = mysql_fetch_row($rs2);
</pre>
it works fine... but I don't think it is good... whenever there is 'code' between queries to get results I think something could be optimized.
Any ideas?
____________________________
. Christian Dechery (lemming)
. http://www.tanamesa.com.br
. Gaita-L Owner / Web Developer