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Unformatted text preview: atabase, it is important to consider possible future
needs and the needs of all types of users of the database. That is, all possible fields
that may be needed should be included in the database structure while defining it.
Although it is possible to modify the database structure at any time, making such
modifications is a time-consuming process. Hence it is always better to design a
database carefully in the first instance and minimize the need to modify the
After defining the structure of a database, the next step in database creation is to
design the forms (custom screens) that permit convenient data entry. Each form
displays a set of fields of the database structure with appropriate amount of blank
spaces against each to enable data entry for those fields.
To facilitate easier data entry, forms are often designed with several fancy features
1. A list box for a field that lists several options on it from which the user can
select a choice. For example, in the form of Figure 16.12, the SEX field may have
a list box that lists the options "Male" and "Female" on it and the user simply
selects the appropriate option for an employee. Depending on the user's selected
option, the system automatically enters "M" or "F" in the SEX filed. Similarly, the
STATE field may have a list box that lists all the states on it from which the user
can select the appropriate option for an employee's address.
2. Simple validation checks defined for a field to ensure correctness of entered
data to some extent. For example, in the form of Figure 16.12, a validation check
may be defined for the POSTAL CODE field to accept only six numeric
characters. With this, the field will not accept less than or more than six
characters. Similarly, a validation check may be defined for the AGE field to
accept values only in the range of 18 to 70 (both inclusive). Validation checks can
also be used to force a certain chara...
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- Spring '14