A few days ago, someone in this list gives me a function (plpgsql) that evaluates if a string is a valid date or not.
It returns 1 or 0 (valid/Not Valid)
The problem is that if the argument is a NULL field the function returns 1.
I don't have experience with plpgsql language.
This is the function
begin
perform $1::date;
return 1;
exception when others then
return 0;
end