Lookup Fields vs. Data Fields

There are 2 types of fields in the primary grid, and there is a different method required to edit them. The first type, data fields, are fields that come from a database table. Editing these fields simply involves keying in new data, although there may be editing masks applied to the field, which restricts the format that new data must adhere to. The bulk of the grid contains data fields. The second type are lookup fields, which are fields that the system calculates or looks up based on the value of a secondary linked field. Because these fields do not exist in the database table, they are normally read-only. To alter them requires that you change the value in the linked field. An example of a lookup field is the PRODNAME field. The linked field in this case is the PRODUCT field. Based on the value in PRODUCT the system looks up the product description in the product table, and displays it in the PRODNAME field. You can’t change the value of PRODNAME directly; instead change the value of PRODUCT (or change the product description).

However, lookup fields sometime include another control that allows the user access to the linked field indirectly. For instance when you click on the PRODNAME field to select it, then click on it a second time, a drop down button appears.

Click on this and the Choose Product window appears. From here you can select the product from a list, or key in the first few letters of the product’s name and have the system select it for you.