You can add the fields, but the behavior that results will depend on the relationship linking the two tables and what relationship options you specify in Managae | Database | Relationships.
I have two tables, Patients (1) to Medications (many). I created a Tab control panel, I was hoping to add fields from the Medications table onto this Tab control panel (and have it be editable). Is that possible?
I also tried the portal approach, but again, it seems like you can view a field from a different table, but you can't add any new to this related table?
This actually has nothing to do with the fact that the fields are in a tab control panel. If you removed the tab control and placed the fields directly on the layout, you'd see the same behavior.
Since you have a one to many relationship, you need a portal so that you can see and work with multiple medication records. But simply linking the tables in a relationship and putting fields in a portal does not mean that FileMaker will automatically create a related record in the related Medications table. If there are no related records linked to the current patient record, then you will not be able to enter data into the field.
The simplest, but not the only, correction to make is to return to manage | Database | relationships, find and double click the relationship line between patients and medication and then select the check box "allow creation of records via this relationship" for the Medications table occurrence. This puts a blank "add row" after the last portal record in your portal. If you enter data into the blank fields in this Add Row, FileMaker will now create the related record and copy over the match field value from your current Patient record in order to properly link this new medication record to your current patient record.
Thank you, thank you, Phil, so much! I was googling and watching the lynda tutorials, but didn't come across the "allow creation of records via this relationship" part! Thank you again!