Hi, Using sub-selects (MySQL 4.1 and higher) you can use something like select count(*)/(select count(*) from table where field1='myvalue') as percentage from table where category='myvalue' group by category;
but I don't think you will gain much in performance this way. I'd rather use two queries - one for the total and one for the percentages. If field1 is indexed select count(*) from table where field1='myvalue' should be quite fast, so I don't think you should worry about having an additional query. HTH -- Dobromir Velev [EMAIL PROTECTED] http://www.websitepulse.com/ > and from a script I calculated my percentage = bigToal/categoryTotal On Friday 08 October 2004 10:48, Jacques Jocelyn wrote: > Hello there, > > Until I had query time restriction due to my web hoster. Meaning > whenever the query was too long, it gets killed ! > Now I have changed my webhoster, I'd like to optimize my queries and I > would like to have your opinion on that. > I wrote multiple queries to prevent any long query time duration such > as : > until now I did the following > - to obtain the total of item which match requirements > -> select count(*) 'bigTotal' from table where field1='myvalue' > > then I selected total of category from the same table to get the > percentage of the total > such as : > -> select count(*) 'categoryTotal' from table where category1='myvalue' > and from a script I calculated my percentage = bigToal/categoryTotal > > -> select count(*) 'categoryTotal' from table where category2='myvalue' > and from a script I calculated my percentage = bigToal/categoryTotal > etc.. > > now, I have planned the following : create ONE query to do all this. > is there a way then to merge the two previous queries in only one ? > > and calculate the percentage at the same time ? > To merge all my category queries, I can use a GROUP BY, but what > about the bigTotal, can have that in the same query ? > > Please advise. > Thanks > > > Best regards, > Jacques Jocelyn -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
