Database Reference
In-Depth Information
Figure 9.3. Using aliases in place of the E MPLOYEE ID N UMBER fields
Although using an alias is acceptable under these circumstances, youshould use them very
judiciously; otherwise, they can become difficult to manage and maintain, eventually con-
ceal or disguise the true meaning of the original fields, and cause you to misunderstand
what the data actually represents. This issue will become even clearer when you begin to
establish table relationships.
Description
This is a complete interpretation of the field. Composing a field description is extremely
beneficial because it forces you (and everyone in the organization) to think carefully about
thenatureofthedatathatwillbestoredinthefield.Youcanberelativelysurethatthefield
requires further refinement if you have difficultly composing a suitable description.
Earlier in the database design process youlearned a set ofguidelines forcomposing a table
description. Similarly, there is a set of guidelines that governs how you compose a proper
field description.
Guidelines for Composing a Field Description
Use a statement that accurately identifies the field and clearly states its purpose.
The description should supplement the field name in terms of defining what the
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