Reasons for creating User Views

The data flow diagram, combined with specific questions posed to users of data about their needs, paves the way for the designer to create user views.
User views are specific views of data created with SQL. The designer defines what data (from what database tables) are made available in these stored queries.
There are three important reasons for creating user views:

1. Data security
2. User needs
3. Calculated fields

User views were defined earlier in terms of data security: they specify which users are permitted access to what data in a database (or across databases). User views ensure that sensitive data remains hidden from unauthorized eyes.

Creating views to meet specific user needs is the flipside of the data security issue. Users must have access to certain data to perform their jobs. It is counterproductive for users to have to wade through data that is irrelevant to their work. User views, therefore, not only protect sensitive data within an organization; they also protect users from being inundated with useless data.

Although it is possible to interact with a DBMS either with basic forms (for a smaller product) or at the SQL command line (for enterprise-level products), doing so requires some measure of specialized training. A business usually has employees who must manipulate data but do not have

1. the necessary expertise,
2. cannot or do not want to gain the necessary expertise, or
3. should not have direct access to the database for security reasons.

Application developers therefore create programs that simplify access to the database for such users. Most DBMSs designed for business use provide some way to develop such applications. The larger the DBMS, the more likely it is that application development requires traditional programming skills. Smaller products support graphic tools for drawing forms and report layouts. The next lesson discusses the third reason for creating user views: calculated fields.