Top > How to import data > Creating relationships between objects > How to create a relationship
In a one to one relationship you may not wish to overwrite the existing relationship. The best way to discover whether there is one or many objects in a relationship is to attempt to add more than one through the form; if you can add more than one, then it is a one to many relationship. If you cannot add more than one, then it is a one to one relationship.
Yes I am concerned:
You may not wish to add a relationship when one already exists or when a specific object instance is in the relationship, e.g., the supplier Adobe should not be removed. In either case, use the Reference Instance Object Processing Option. Reference Instance lets you add criteria for finding the object instance. The advantage of using Reference Instance over the Update option, which could also be used, is that there is no update needed to the second object—you are simply relating them. On the relationship, choose Create or Update as the Relationship Processing Option.
You wish to assign Wil Smith as the user to a hardware asset, but only if there is no one already assigned. There can only be one assignment on a hardware asset. You would add Wil Smith as the Reference Instance criteria for the user object in the relationship.
No I am not concerned:
In a one to many relationship it may not matter to you if another relationship is added. In a one to one relationship, it also may not matter to you if the existing relationship is overwritten. Choose Reference Instance as the Object Processing Option and choose Create or Update as the Relationship Processing Option.