Option 3: https://groups.google.com/d/msg/web2py/CRPySzABQTk/8jylUabyFTQJ
Anthony
On Saturday, January 26, 2013 12:35:26 PM UTC-5, rochacbruno wrote:
>
> I can think on two options.
>
> *1. Unique Key*
>
> db.define_table("table",
> Field("table_a", "reference table_a"),
> Field("table_b", "reference table_b"),
> Field("unikey", unique=True, notnull=True, compute=lambda row:
> "%(table_a)s-%(table_b)s" % row)
> )
>
>
> *2. Form validator*
>
> def check_unique(form):
> if db((db.table.table_a == form.vars.table_a) & (db.table.table_b ==
> form.vars.table_b)).count():
> form.errors.table_a = "You cannot insert or edit a duplicate
> combination"
>
> form = SQLFORM(db.table).process(onvalidation=check_unique)
>
> Mybe it can be implemented as a Field Validator, have to try.
>
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