I have discovered something that helps a little here.

If a column can accept a null value and you dont assign a bind value to it, thats ok, a null is inserted there. But for non-null columns that arent assigned a bind value, an error like this occurs: (for MySQL at least)

DBD::mysql::st execute failed: Column 'blah' cannot be null at bind_test.pl line 32.

Yes this is probably well-documented somewhere, but i thought i had read quite a lot of bind param documentation, and much more was learned in working on this problem.

*** Note: I have only tested this for char and int type columns, im assuming that other columns will behave similarly. (assuming will bite me though - as it always does)