Justin Clift <aa2@bigpond.net.au> writes:
> "Bad (null) varchar() external representation"
This is a known stupidity in 7.0.* and before: length(varchar) doesn't
like NULLs:
play=> select length(null::varchar);
ERROR: Bad (null) varchar() external representation
It's fixed for 7.1. If it's really bothering you in 7.0.*, find that
error string in src/backend/utils/adt/varchar.c and change the code to
return 0 instead of raising an error for NULL input.
But, as someone else pointed out, the constraint expressions you are
using are redundant anyway, given the declared column length limits.
Getting rid of the constraints might be your easiest workaround for now.
regards, tom lane