In QGIS 3.18. In a shapefile attribute table, I have some fields with concatenated values (with commas as the delimiter). Some of the values are duplicate, and I would like to remove them. For example, if an attribute value is 37.3,37.8,44.A2,37.3,37.31, I'd like an expression that will catch the two instances of "37.3" and remove one of them (without removing the instance of "37.31" which is a different value).
I have not found a simple SQL expression that can do this in the field calculator, though I am a relative beginner at SQL (and a complete newbie at Python). On this site, there are similar questions here, here and here but they are rather old, not for QGIS, and ever-so-slightly out of my league (perhaps the formulas are adaptable, but I'm not sure how).