how to implement a picklist for a FK field in a table inside a form and grid section.
Use the Choices attribute and specify a SQL Select statement. For numeric fields, use the Choices + Get data mapping / Set data mapping as demonstrated in the example_datamapping App.
Taking the southwind orders table as an example, it contains the customerid field, e.g. ‘ALFKI’. For that, I would just use choices – select customerid from customers – and include an ‘order by’ or ‘where’ clause if required. The orders table also has employeeid. If I wanted to display the lastname of the employee, rather than their id, I would use data mapping to display the lastname (Get data mapping) and my select statement would be based on the lastname. I would use the Set data mapping to store the employeeid for the selected lastname back to the table.
So if you just want to display a choice list, just use choices and if you want to display a name or a description associated with an id (another field in the lookup table), use the get/set data mapping as well.