Student Age Subject Adam 15 Biology, Maths Alex 14 Maths Stuart 17 Maths ID Name Department Phone Number 1 Rajesh Computer 3452342,1234563,2345612 2 Suresh Electronics 2398521,2323177,5302994 3 Praba Civil 3958218
1st Normal Form : any row must not have a column in which more than one value is saved Student Age Subject Adam 15 Biology Adam 15 Maths Alex 14 Maths Stuart 17 Maths
2nd Normal Form : As per the Second Normal Form there must not be any partial dependency of any column on primary key. It means that for a table that has concatenated primary key, each column in the table that is not part of the primary key must depend upon the entire concatenated key for its existence. If any column depends only on one part of the concatenated key, then the table is NOT in Second normal form.
First table Student Age Adam 15 Alex 14 Stuart 17 Second table Student Subject Adam Biology Adam Maths Alex Maths Stuart Maths
These table can not be decomposed any more as all of these are already normalized
TABLE :: ID Name Department Phone Number`[` This table can also be normalised upto 2nf at max`] ` First Normal Form (1NF) : ID Name Department Phone Number 1 Rajesh Computer 3452342 1 Rajesh Computer 1234563 1 Rajesh Computer 2345612 2 Suresh Electronics 2398521 2 Suresh Electronics 2323177 2 Suresh Electronics 5302994 3 Praba Civil 3958218 Second Normal Form (2NF) ID Name Department 1 Rajesh Computer 2 Suresh Electronics 3 Praba Civil ID Phone Number 1 3452342 1 1234563 1 2345612 2 2398521 2 2323177 2 5302994 3 3958218