Topic group

Like any file, tables and the information they contain can be corrupted or destroyed if used improperly.

If, for example, you design an application that prevents entry of a number greater than 10 in a field called NUMITEMS, and the existing data is contained in an older .DBF table, someone could circumvent your data constraint of "not greater than 10" by opening the table in Run mode, adding a new row with a value of 11 in the NUMITEMS field, and saving the table.

Most table types, including the new .DBF7 format, allow the table developer to enforce rules at the table level in order to prevent such problems from occurring. But even with such safeguards, developers should caution users who have access to tables that database integrity can be compromised by editing table data directly in dBASE Plus or in any other application—including spreadsheets and word processors.

Developers can also take other simple precautions, such as placing data in folders at levels casual users may not venture into, or naming data directories with numbers instead of with tempting titles like "databases."

It also helps to understand exactly when and how your databases can be opened and modified from within dBASE Plus.