I am trying to create a 1:1 Relationship with an object. Where they will exist in the child object only once to prevent duplication of the same master objects entry in the detail table. Is there a validation rule i can use to do this? or am i forced to use a trigger.

For eg.

Parent_c.Name, can only exist ONCE in the Child_c, so each Child_c.Parent_r.Name will have a unique value. Is there anyway to achieve this via the validation rules or filter a lookup. Thanks in advance.

1 Answer 1


You have to create new roll-up field (for counting child records) and validation rule which said that value in this field can't be > 1. Thanks to that you will get 1-to-1 relationship

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .