Database Reference
In-Depth Information
Figure 7.27. Resolving the multiple sets of duplicate fields in the STUDENTS table
Now that you're familiar with the Elements of the Ideal Table, review your table structures
and refine them as necessary. When you're in doubt about a particular table, sketch its
structureonapieceofpaperandloaditwithsampledata.You'llthenbeabletoresolvethe
anomalies revealed by the data.
Establishing Subset Tables
As you refine the structures of your tables, you may find that some of the fields in a partic-
ulartabledonotalwayscontainvalues.Thissituationwillnotaffectyourabilitytoretrieve
information from the table, but it can indicate that the table might need further refinement.
Consider the structure of the INVENTORY table in
Figure 7.28
.
