List of Contributions

Thanks All. I had tried the update using the expression Area-Area_buildings as that seemed the most obvious. It didn't work.  It's comforting that someone else has suggested it - means I'm not being daft.  I suspect I had the columns formatted wrong so it couldn't do the sum.  I got around ...

Help me. I have what I think is a really basic query but can't find the answer anywhere! I have a table, with a column 'Area' and a column 'Area_buildings'. I then have an area called 'Total_applicable_area' which I want to auto update to be 'Area' minus 'Area_buildings'. I just can't seem to write ...