waht is the difference between primary key and super key?

Answer Posted / 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....

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