waht is the difference between primary key and super key?
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Answer / nilesh
Different set of attributes which are able to identify any
row in the database is known as super key. And minimal
super key is termed as candidate key i.e. among set of
super keys one with minimum number of attributes. Primary
key could be any key which is able to identify a specific
row in database in a unique manner.
| Is This Answer Correct ? | 56 Yes | 19 No |
Answer / manoj jain
Primary key is subset of candidate key
primary key=not null+unique
candidate key is minimal form of super key ie. candidate key
is subset of super key
common feature:-
primary key,super key,candidate key is used to identify a
entity in relation
| Is This Answer Correct ? | 30 Yes | 4 No |
Answer / avinash
primary key:
primary key could be any key which is able to identify
a specific row in data base in a unique manner.
super key;
different set of attributes which are able to identify
any row in the database is known as super key.
| Is This Answer Correct ? | 29 Yes | 6 No |
Answer / kishore singh bisht
primary key is a uniquely identified key,in primary key we use only a single attribute to identify a row.......
example:- roll no. of an student, employee id etc.
primary key=unique+not null.
and super key is a combination of two or more attributes which make the uniqueness.......
ex:-name+d.o.b+contact no...
these three attributes make the uniqueness by which we can easily identify.............
| Is This Answer Correct ? | 11 Yes | 5 No |
Answer / sweety singh
superkey is a set of attributes that can uniquely identify
individual tuples whereas a key or a primary key is a
minimal super key that can identify individual tuples.
ex..eno pno hrs
1 1 2
2 4 7
i.e...here eno,pno,hrs together are a superkey but eno,pno
is primary key and hence eno,pno cant hav null values and
repeated enteries....
| Is This Answer Correct ? | 8 Yes | 3 No |
Answer / zain zany (gcu lahore)
Basic difference in a primary key and Super key is that in
Primary key,we use only a single attribute to identify a
row,where as in,
Super key,we use Different set of attributes to identify any
row in database...
| Is This Answer Correct ? | 16 Yes | 21 No |
Primary is a unik value it not contain null and only single
in a table.
| Is This Answer Correct ? | 17 Yes | 32 No |
Answer / guneetinder singh
primary key has two properties
* uniqueness.
* not null value acceptable.
where as super key is candidate key minus primary key
attributes.
| Is This Answer Correct ? | 14 Yes | 32 No |
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