Is this information in 1 NF? Explain why or why not. Is this information in 2NF?
ID: 3569693 • Letter: I
Question
Is this information in 1 NF? Explain why or why not.
Is this information in 2NF? Explain why or why not.
Is this information in 3NF? Explain why or why not.
ATTriBUTE nAME
ConTEnTs
ATTriBUTE TyPE (*)
PriMAry kEy (Pk) AnD/or ForEign kEy (Fk)
rEFErEnCEs
LOG_DATE
Log-in (system) date
PK
LOG_TIME
Log-in (system) time
PK
LOG_READER
Magnetic card reader number
PK
USER_ID
User identification (ID)
FK
USER
* The attribute type may be Composite (C), Derived (D), or Multivalued (M).
ATTriBUTE nAME
ConTEnTs
ATTriBUTE TyPE (*)
PriMAry kEy (Pk) AnD/or ForEign kEy (Fk)
rEFErEnCEs
LOG_DATE
Log-in (system) date
PK
LOG_TIME
Log-in (system) time
PK
LOG_READER
Magnetic card reader number
PK
USER_ID
User identification (ID)
FK
USER
* The attribute type may be Composite (C), Derived (D), or Multivalued (M).
Explanation / Answer
A table is said to be in 1NF if each cell in a table has only one piece of information, and there can be no duplicate rows.
So the above table is in 1NF as each cell in the row has only one piece of information.
A table is in 2NF if it satisfies the 1NF and other attributes (non-prime attributes) of the table are totally dependent on the WHOLE primary key.
So the given table is in 2NF as there are no extra attributes (non-prime attributes) in the table.So the question of non- prime attributes not depending on the primary key doesn't arise.
A table is in 3NF if it satisfies the 1NF and other attributes (non-prime attributes) of the table are dependent ONLY on the WHOLE primary key.
The table is in 3NF as there are no extra attributes in the table.So the question of non- prime attributes not depending on the primary key doesn't arise.
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