Reference fields are very powerful fields which make it possible to connect Forms to other Forms or to the Geodatabase. Users can link the Records they add to a Form to the Records of another Form.
To link a Record of one Form to a Record of another Form you need to use as common reference:
- a Key field or
- a Serial Number field
The maximum length of the characters of a Key field to appear in a dropdown result of a Reference field is 128 characters.
Reference fields vs selection fields
Both Reference and Selection fields allow you to create lists of options. However, as these fields serve different purposes, it is important to choose the appropriate type when designing a Form.
A Selection field allows you to create a list of options inside the Form whereas a Reference field references another Form (a 'Reference Form') where each option is another Record. In the second case, as the option is an actual Record, it is possible to include more information about that option (i.e. meta-data or other kind of information) in the referenced Form. You can use as many fields as needed to capture that information and by making them Key fields you can also bring that information into the initial Form (creating the 'cascading effect').
We strongly suggest the following best practices:
- Use a Single Selection field to capture a basic list of options that don't require further meta-data or additional information. Examples: age categories, list of options for biological sex, etc.
- Use a Reference field to link to a Reference Form where you will collect additional information for each option (Record). You expect changes to occur on that data (data is described as dynamic rather than static) and you need to link to these options in many Forms in your Database in a consistent way. Examples: partner organizations, list of institutions/entities, etc.
If you find that the required record is missing when you are entering a Reference field response, you can add a record in the referenced form directly by selecting "Add reference record in ...". You will be navigated to the referenced form where you can enter the new record. Once completed, you will be returned to your original form to continue data entry.
Note: this option is only visible if you have adequate permissions to add a record in the referenced form.