Types of Normal Forms in DBMS

1. Unnormalized form or UNF
2. First Normal Form or 1NF
3. Second Normal Form or 2NF
4. Third Normal Form or 3NF
5. Elementary key normal form or EKNF
6. Boyce Codd Normal Form or BCNF
7. Fourth normal form or 4NF
8. Essential tuple normal form or ETNF
9. Fifth normal form or 5NF
10. Domain-key normal form or DKNF
11. Sixth normal form or 6NF

StudentId      Name       Course 
 
  101           Raj        Mathematics
                          Chemistry
  102          Nilesh      Chemistry
  103          Sanu        Physics
                          Chemistry

1. UNF can deal with the complex data structures,
2. querying in UNF is simpler,
3. Restructuring the data is easier.

StudentId      Name       Course1        course2 
 
  101          Raj         Mathematics    Chemistry
  102          Nilesh      Chemistry
  103          Sanu        Physics        Chemistry

• It is in first normal form or 1NF
• It doesn’t contain any partial dependencies. (It shouldn’t have any non-prime attribute which is functionally dependent on any proper subset of the candidate key of the relation.).

• R should be in 2NF
• X should be candidate key or superkey, or
• Y should be prime attribute

• Y" title="Rendered by QuickLaTeX.com" height="20" width="101" style="vertical-align: -1px;">be any non-trivial functional dependency over the R is BCNF if X is a Candidate Key or a SuperKey.
or
• Y" title="Rendered by QuickLaTeX.com" height="20" width="101" style="vertical-align: -1px;"> is a trivial functional dependency (i.e, Y subset of X),

• X is a candidate key or a super key of the relation,
or
• X union Y = R

1. domain constraints,
2. key constraints.