@PaulWhite Yes, it would appear that cross-table SQL doesn't work - but that SQL can still be pretty useful within a table... err... I tried this - basically the idea is that a manager can't lend over 100 (K, M....). The problem with the implementation is that the TRIGGER which is created in the background is a before TRIGGER, so it allows the SUM go over 100, but not over 200... see
here ...