Table validation rule - allow only one occurence in a field

  • Thread starter Thread starter jaworski_m
  • Start date Start date
J

jaworski_m

Hello,
Suppose there's a table (many side):

ID (PK)
ID_foreign (FK)
field 1
field 2
yes/no field

How can I allow ONLY ONE record to have "yes/no field" = True? (with table
validation rule)
In case a user sets a second record "yes/no field" = True an error is
triggered.

Thank you for suggestions.

Access 2003
 
You do realize that with this rule enforced at table level, you can only have
two records in your table, right? (one Yes and one No).
Click to expand...

Yes, correct. But I would like to have Many records (not only 2) and only
ONE with value "Yes".
 
I do not hink you can do it in a table but in a form.

If DSum <>0 then message and not allow change of checkbox.
 
Back
Top