2. Indroduction
What Is Keys?
*keys are very important part of
relational data base.
*they are used to establish and
identify relation between tables.
* they also ensure that each record
within a table can be uniquely identified by
combination of one or more fields within a
table.
3. DBMS has five types of keys in it and they
all has different functionality.
The keys are all follows:
*Super key
*Candidate key
*Primary key
*Foreign key
*Composite key
4. Super key:
A super key is a set of ONE or MORE
columns(Attributes) to uniquely identify rows in a
table.
12. Composite key:
*A key that consists of more
than one atributes to uniquely identify rows(also
known as records or tubels)in a table is called
COMPOSITE KEY.