I have an MySQL database with a table "players".
I have a couple of thousand playerid's
Each playerid has (for now) two records; one for round=1 and one for existing round (10 in the example).
I need some update sentence that goes though all my playerids where round=10 (existing round) and alter gain to last quality subtracted first quality, hence sets gain=2 in the last of the two records...
This is how I want my second record to look:
gain: 2 <- different