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enables the user to display the data in the various fields of a record in the same
screen format as that used for data entry. The user can specify the record to be
displayed by specifying its key field value. The database system usually also
provides the flexibility to the user to move between records for viewing different
records, such as "go to the first record", "go to the previous record", "go the next
record", and "go to the last record".
Many database systems also provide a facility to set up a filter that allows the user
to browse through and view only those records, which meet some criterion. For
example, in the employee database created by using the form of Figure 16.12, if
the user wants to view the records of only female employees, the user can set a filter for the "Sex" field and only the records that contain "F" in that field will be
displayed. Note that while a filter is set, to user cannot access the records that do
not meet the filter criteria. Filters provide a quick and convenient way narrow
down the number of records the user has to work with.
The command for modifying a record enables the user to not only view but also to
update the data in the various fields of a record. To modify the contents of a
particular field of a record, the record is first displayed, then the cursor is
positioned in the field at the appropriate character position where the change is to
be made by clicking the mouse there, and then the contents of the field is
appropriately edited. The data in any other field of the record can be similarly
edited. Finally, the enter key has to be pressed for the changes to take effect. Some
database systems may prompt the user to confirm the changes before effecting the
changes and allowing the user to mo to another record.
The command for deleting a record enables the user to remove the selected record
from the database. To delete record, the user first selects the record either by
specifying its key field value or by using the facility to mo between records just as
is done in the case of viewing a record. The user then uses the delete command,
and the record is deleted. Mos...
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- Spring '14