You can try IS_EMPTY_OR(IS_IN_DB(...)) (also works with IS_IN_SET). You might also want to specify a 'zero' option. See http://web2py.com/book/default/chapter/07#Validators.
On Wednesday, November 2, 2011 10:35:26 AM UTC-4, Bianca Cadaveri wrote: > > Hello, > > I would like my users to be able to choose nothing, if they want to, > in a drop-down menu. The drop-down menu is generated using SQLFORM. > By default the validator does not accept that my users choose nothing. > How to change that ? > > Thank you very much, > Bianca >
