What is the diff. bwt. primary key and unique key?
Answers were Sorted based on User's Feedback
Answer / janhvee
diff. between primary key and unique is unique key can be
null but primary key can't be null.
one table can have only one primary key but unique key can
be multiple keys
| Is This Answer Correct ? | 17 Yes | 0 No |
Answer / rakesh ranjan
IN PRIMARY KEY IS ONLY IN ANY TABLE BUT WHEN WE TALKING
ABOUT UNIQUE KEY, IT CAN BE NULL.
| Is This Answer Correct ? | 5 Yes | 1 No |
primary is not allow null value.but unique can be allow null
value
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / sonu kumar
primary of any table can't be null but unique can be
primary key may be a unique key but unique can't be a primary key b/c primary key of any relation cant be a null value
| Is This Answer Correct ? | 0 Yes | 0 No |
How do I save in mysql?
Why myisam is faster than innodb?
How can you find out the version of the installed mysql?
Which datatype is used for email in mysql?
How to print message in mysql trigger?
Is there a way to see the files which are stored?
How can you create and drop view in mysql?
How do I make an action query?
What is InnoDB?
Why do we need mysql?
How do you use auto increment?
Is mysql written in c?
Oracle (3259)
SQL Server (4518)
MS Access (429)
MySQL (1402)
Postgre (483)
Sybase (267)
DB Architecture (141)
DB Administration (291)
DB Development (113)
SQL PLSQL (3330)
MongoDB (502)
IBM Informix (50)
Neo4j (82)
InfluxDB (0)
Apache CouchDB (44)
Firebird (5)
Database Management (1411)
Databases AllOther (288)