Second Normal Form (2NF)
Definition of Second Normal Form:
Second
Normal Form is a more restricted definition than First Normal Form.
Second Normal Form (2NF) requires a separate Table for
values that can be used by multiple Tables.
The Rating Table
is a good example. The Rating data is limited and static: It doesn't
change much.
Users need
to look up a Rating in the Rating Table and save it in the Movie
Table.
So,
tblMovies and tblRating have a common Field, Rating, which is TEXT
in both Tables.
Memo to Self: The common Field
can be TEXT or NUMBER. However, the Data Type has to MATCH, MATCH,
MATCH.
Text goes with Text.
Numbers go with Numbers.
Microsoft Access 2010: Example of Tables in Second
Normal Form
The
Movie Table gets the Rating from the Rating Table