define primary key & secondary key?
Answers were Sorted based on User's Feedback
Answer / manoj
primary key is a key which always accept unique value.
secondary key is a key which when you are making primary key
for more than one column as primary key for retrieving of
reords.
eg.
create table tnam
(ano number,
bno number,
bname char(12),
primary key(ano,bno))
In this bno is secondary key.
| Is This Answer Correct ? | 31 Yes | 18 No |
Answer / renu kakkar
PRIMARY REPRESENTS THE ROW/TUPPLE UNIQUELY WHEREAS
SECONDARY KEY REPRESENTS THE SET OF TUPPLES
EMPLOY_ID IS A PRIMARY KEY AND EMPLOY_DEPTT. IS A SECONDARY
KEY.
| Is This Answer Correct ? | 3 Yes | 9 No |
What are analytic functions in sql?
Difference between DBMS and RDBMS...CODD's rules
What is extent clause in table space?
What is clustered index in sql?
What are % type and % rowtype?
What is delimiter sql?
What does bitemporal mean?
What is the current version of postgresql?
What is the primary key?
What is sql data?
Can a procedure in a package be overloaded?
What is sql used for?
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)