Topic group Related topics

dBASE Plus’s password dialogs are activated only by encrypted tables. Password protection alone is inadequate to protect a sensitive table unless the table is encrypted, because an intruder, having gained access to the machine or server on which the application is running, could use another application to read the data from the hard disk.

Once an authorized user gains access to your application by providing the correct password, the user might be offered a restricted choice of a variety of tables, with different access privileges, depending on the login level used to access the application. dBASE Plus supports the full range of table- and row-level security features for DBF tables, so you can create up to 8 user access levels and 3 privilege levels, precisely controlling access by different classes of users to specific tables and even to specific rowsets in those tables.

To link any encrypted table to a form (and thereby enable automatic password protection), you need only create a Query object for that table on your form. To do this, simply drag the table icon of the encrypted table from the Navigator’s Tables page to your form surface in Form designer. (At this time, while in Design mode, you will have to supply access information to the encrypted table.) This is all you need to do to ensure that dBASE Plus will activate the automatic password dialog. See Form Designer for guidance on adding Query objects to forms.

After your form is run and the user activates some event (a button click, for example) to access a restricted table, the Borland Database Engine (BDE) attempts to open that table. Because the table is encrypted, dBASE Plus automatically displays the appropriate password dialog with fields for the input required by that table type. The type of security available varies according to table type.

The original dBASE Plus form is temporarily displaced and the user is presented with a password dialog. To gain access to your application (and its underlying encrypted table), the user must provide the particular security information required by that table or database.