3: Creating the Demonstration System Files

3.11 Modifying an RMSfile by Deleting a Field

In the following exercise we modify an RMSfile by deleting the telephone field for the sub RMSfile. (Note: We also restore it, however, prior to writing the file.)

1. From the Data Files Menu, select choice D2 - Modify File Definition.

Toolkit presents the Modify Data File Definition parameter form.

Enter sub in the field for the filename, then press STORE <F5>.

2. The screen will display the File Definition form.

3. Press the SWITCH key <F7>. This appends a Field Description form to the File Definition form.

4. Press the NEXT key <F3>. The telephone field should appear.

5. To delete the telephone field, press the GOLD key <F1> followed by the D key. The Enter Field Descriptions form containing the description of the telephone field is cleared.

Now that you have successfully deleted the data field, we restore (by re-adding) it to the RMSfile.

6. Press the ADD key <F6>. Notice that the word ADD appears in the lower left-hand corner of the screen. Press the Line Feed key five times. The information from the last deleted (or stored) Field Description form (in this case, the telephone field) is duplicated in the blank fields of the current Field Description form.

Note: If your keyboard does not have a Line Feed key, you may wish to contact your system administrator or read C/Base Reference Manual Chapter 11, Creating Terminal Definitions to establish an alternate method of performing this function. You may, however, proceed simply by re-entering the old description of the telephone field.

7. To store the new description, press the STORE key <F5>.

8. Now that all the changes have been made to the RMSfile, write the modified file by pressing the EXIT key <F8>.

The program displays the following message:

There is a short pause while this file conversion takes place.

Press RETURN to display the Data Files Menu.

9. Select choice L2 - List Data File Dictionary from the Data Files Menu.

On the List data File Dictionary parameter form, specify the RMSfile sub and press STORE <F5>.

Press RETURN to redisplay the Data Files Menu.

Select choice R - Return to toolkit menu and press RETURN. The Toolkit Menu is displayed.

This concludes the steps to modify the RMSfile sub by deleting (and then restoring) the telephone field.