Entering Data in Access Tables

Ease of data entry is a primary criterion for an effective database development environment. Most of your Access database applications probably will use forms for data entry. In many instances, however, entering data in Table Datasheet view is quicker than using a form, especially during the database development cycle. For example, it's a good idea to test your proposed database structure before you commit to designing the forms and reports. Although the Name AutoCorrect feature introduced by Access 2000 reduces discrepancies, changing table and field names or altering relationships between tables after you create a collection of forms and reports can involve a substantial amount of work.

To test the database design, you must enter test data. In this instance, using Table Datasheet view to enter data makes more sense than using a form. Even if you import data from another database type or from a spreadsheet, you probably need to edit the data to make it compatible with your new application. The first part of this chapter concentrates on data entry and editing methods.

Another important factor in a database development environment is maintaining the integrity of your data. Entity integrity rules limit the data you enter in fields to a particular range or set of valid values.

Like earlier versions, Access 2003 lets you enforce entity integrity rules (often called business rules) at the field and table levels. You enforce entity integrity (also called domain integrity) by entering expressions as the value of the Validation Rule property of fields and tables. This chapter shows you how to use simple expressions for domain integrity validation rules. After you master Jet/VBA operators and expressions in Chapter 10, "Understanding Jet Operators and Expressions," you can write complex validation rules that minimize the possibility of data entry errors in your Jet tables.