Database Reference
In-Depth Information
Here is our 1NF model after answering these questions, breaking up
Survey Respondent
Name
into first and last name, and adding the many-to-many relationship between
Com-
pleted Survey
and
Survey Question
:
Note that there might be additional attributes in the
Survey
subtypes that need to be iden-
tified.
Second Normal Form (2NF)
For second normal form, we need to ensure that each entity contains the minimal set of at-
tributes that uniquely identifies each entity instance. In other words, each entity must con-
tain the minimal primary key. We therefore complete the following template:
Question
Yes? No?
Is a
SIC Code
needed to retrieve a single instance of
Industry Name
?
✓
Is an
Organization DUNS Number
needed to retrieve a single instance of
Organization Name
?
✓
