More 2NF
Our
data model is still not in 2NF. The
Record Label attribute has only one value for each
CD, but we see the same Record
Label in multiple CD rows. As we saw
with Band Name, this duplication indicates that
Record Label should be part of its own entity.
Each Record Label releases one or many
CD rows. Each CD is released by
only one Record Label. Figure 7-10 shows this relationship with the data model in
2NF.
 |
Figure 7-10. Our data model in second normal form
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