Bruce, I've now added a program to list surveys with no surveyors. Strictly speaking it's centrelines with no surveyors but it list the surveys which contain those centrelines Download available i=from the same URL http://www.daveclucas.com/cms/administrator/index.php?option=com_phocadownload&view=phocadownloadfiles
Martin, I know about maps with submaps from different surveys and I use this approach but I was addressing the specific question from Bruce. I'm not sure if it has any impact on the data queries though as the queried data has already been collated by Therion. There are things in the database which I don't understand such as the blank row for each centreline. I suspect this is a row created for either explo lengths or surface lengths but I dfon't know as so far, I haven;t got any such data. Dave Clucas daveclucas.com sarawak-caves.com dave.clucas at icloud.com Exploring the World - One cave at a time -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mailman.speleo.sk/pipermail/therion/attachments/20140719/cf0153bb/attachment.html>