adspace


If we declare constraints Unique and Not null on a single
column then it will act as a Primary key, so what is the use
of primary key??

Answer Posted / ashok

Internally , There is same as primary key and unique not null.
You can say unique + not null is higher step of primary key .
So there is no basic difference between this two.

Is This Answer Correct ?    7 Yes 11 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is dbms? : Sql dba

1070


Is inner join faster than left join?

1287


Can delete statement be rollbacked?

1065


Can we use distinct and group by together?

1146


Can we rollback truncate?

1083


what is schema? : Sql dba

1163


how to start mysql server? : Sql dba

1279


What is your daily office routine?

2353


What is the best sql course?

1064


Do we need to rebuild index after truncate?

1154


how to escape special characters in sql statements? : Sql dba

1124


what are all the common sql function? : Sql dba

1141


what is bcp? When does it used? : Sql dba

1065


what is collation? : Sql dba

1242


Is primary key always clustered index?

1101