What are different types of Keys? Please explain all the
keys with a suitable example.
Answer Posted / abdul malik(new college)
keys-A key allows us to identify a set of attributes and
thus distinguishes entities from each other.keys also help
uniquely identify relationships,and thus distinguishes
relation with each other.
different types of keys:
(i)super key
(ii)candidate key
(iii)primary key
(iv)unique key
(v)foreign key
sk-it is a set of one or more attributes that allows us to
identify uniquely an entity set.
ck-a super key for which no subset is a superkey is called
a candidate key.
pk-In a table pk does not take no repetation and does not
allow null values.
fk-it acts as a referential order.it refers one table from
the another one.
| Is This Answer Correct ? | 53 Yes | 9 No |
Post New Answer View All Answers
What is the native system stored procedure to execute a command against all databases?
What are dml triggers and types of dml triggers?
What is store procedure?
How to transfer an existing table from one schema to another schema in ms sql server?
How to end a stored procedure properly in ms sql server?
What happens when unicode strings concatenate with non-unicode strings?
How to assign null values to variables or columns?
Explain sql server service broker?
How do I find the query plan in sql server?
What are the types of dml?
What do you mean by recursive stored procedure?
What are the different types of collation sensitivity in sql server?
How to transfer a table from one schema to another?
Explain the stored procedure?
What is difference between sql and sql server?