Not sure what is happening here. When I query the database I find every survey has an extra CENTRELINE row with all the fields containing NULL or zero values apart from the first row which I think has no centrelines as it’s the index file. Test 2 Centreline ID Survey ID NAME TITLE 2 1 No Title 34 31 1954 1954 32 31 1954 No Title 33 31 1954 1954 38 36 1954_ramps 1954 Ramps 37 36 1954_ramps No Title 42 40 1954-endloop 1954-endloop 41 40 1954-endloop No Title 46 44 1954_up_ramp 1954 45 44 1954_up_ramp No Title 50 48 nothing_to_be_proud_of Nothing to be proud of 49 48 nothing_to_be_proud_of No Title 824 822 1954_garden_extension 1954 - Garden of Good and Evil extensions 823 822 1954_garden_extension No Title 1032 1030 a65_highway_to_the_dales dirty yorkshire habits 1031 1030 a65_highway_to_the_dales No Title 1251 1250 aah_disto No Title 1252 1250 aah_disto Aah Disto 1255 1254 ancestor_passage No Title 1256 1254 ancestor_passage Ancestor Passage Dave Clucas daveclucas.com sarawak-caves.com dave.clucas@icloud.com Exploring the World - One cave at a time