2: Using the Demonstration Subscription System

2.9 Deleting Records

Deleting a data file record requires that the record first be located and then deleted (by pressing the GOLD key <F1> followed by the D key).

Exercise 9

Goal: Delete the record just added for Crossword Puzzles magazine.

1. Use the QUERY and FIND functions, to locate the record.

2. Delete the record by pressing the GOLD key <F1> and then the Dkey. Once this is done the record has been deleted from the data file.

PROCEED IMMEDIATELY TO THE FOLLOWING EXERCISE.

Exercise 10

Goal: Change the key field of the Crossword Puzzles magazine from cwpuz to cwpuzz.

1. Press the ADD key <F6> and enter the new magazine code, cwpuzz.

2. Duplicate the other fields by using the Line Feed key.

3. Store the record by pressing the STORE key <F5>.

Comments:

The method outlined in this and the preceding exercise is useful to change a record’s primary key field since, once a record has been stored, the key field may not be changed using the UPDATE function.

Note:

Delete the record for cwpuzz (as outlined in the preceding exercise) so that the next time this Tutorial is used the contents of the data files will reflect the illustrations.