How do you create and use lookup fields and combo boxes for data entry in Access?

1 What are lookup fields and combo boxes?

A lookup field is a field that stores a value from another table or query, based on a matching criterion. For example, you can have a lookup field that shows the customer name based on the customer ID. A combo box is a control that you can add to a form to display a lookup field. It combines a text box and a drop-down list, so you can either select a value from the list or type a new one. For example, you can have a combo box that shows the product name based on the product ID.

2 How to create a lookup field?

To create a lookup field, you need to have a table or query that contains the values you want to display in the lookup field, referred to as the lookup source. Additionally, you need another table or query that contains the field you want to use as the lookup field, referred to as the lookup target. The lookup target field should have the same data type as the lookup source field. To create the lookup field, open the lookup target table or query in Design View and select the field you want to use as the lookup field. Then, click on the Lookup tab in the Field Properties section and set the Display Control property to Combo Box and Row Source Type property to Table/Query. After clicking on the ellipsis (...) button to open the Query Builder, add the lookup source table or query and select the fields you want to display in the lookup field. You can also add criteria or sorting options if needed before closing and saving changes to the lookup target table or query.

3 How to create a combo box?

To create a combo box, you need to have a form that is based on the lookup target table or query. You can either use an existing form or create a new one using the Form Wizard or the Form Design tools. To create the combo box, open the form in Design View and click on the Combo Box tool in the Controls group on the Design tab. Then click and drag where you want to place it. In the Combo Box Wizard, choose the option that says "I want the combo box to look up the values in a table or query" and select the lookup source table or query and fields you want to display. Additionally, decide how you want to sort the values, set the width of the combo box and columns, and enter a label for it. Finally, save your changes to the form.

4 How to use lookup fields and combo boxes?

To use lookup fields and combo boxes, you need to open the form in Form View or Datasheet View. To enter or edit data in a lookup field or a combo box, click on the field or box to activate it. Then, if you want to select a value from the list, click on the drop-down arrow and choose the desired value. If you want to type a new value, type it in the text box. If the lookup field or the combo box allows new values, it will be added to the list; otherwise, an error message will appear. Finally, press Enter or Tab to move to the next field.

5 What are the benefits of lookup fields and combo boxes?

Lookup fields and combo boxes have several advantages when it comes to data entry in Access. By providing a list of values to choose from, they make data entry faster and easier, while reducing errors by preventing typos and invalid values. Additionally, they ensure data consistency by using the same values across tables and queries, and improve data quality by allowing you to update or delete values in one place and have them reflected in all lookup fields and combo boxes.

6 What are the limitations of lookup fields and combo boxes?

Lookup fields and combo boxes have several limitations that you should be aware of, such as slowing down your database performance if you have too many of them or if they use complex queries as their lookup source. These features can also cause data integrity problems if you delete or modify values in the lookup source without updating the lookup target, or if you use different lookup sources for the same lookup target. Additionally, they can be confusing for users if you use different labels or formats for the same lookup field or combo box in different forms or reports.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?