Can we have more than one NULL in a column having unique
constraint?
Answers were Sorted based on User's Feedback
Answer / atikullah
No, I think unique constraint contain no duplicate value in
a column. There are only contains unique value
| Is This Answer Correct ? | 0 Yes | 1 No |
Answer / rammohan176
yes Unique constraint accept more than one null.... because null is always not equal to another null value.i.e null<>null.
if any body have doubt please check this
CREATE TABLE TEST1 ( ENO NUMBER CONSTRAINT EU UNIQUE,
NAME1 VARCHAR2(10))
INSERT INTO TEST1 (NAME1) VALUES('RAM')
INSERT INTO TEST1 (NAME1) VALUES('KARTHIK')
INSERT INTO TEST1 (NAME1) VALUES('SANTHOSH')
INSERT INTO TEST1 (NAME1) VALUES('SANDY')
| Is This Answer Correct ? | 0 Yes | 1 No |
What is outer join in sql server joins?
Explain relational data?
What is a non-clustered index?
How to disable triggers using "disable trigger"?
what are the Prerequisites for Replication?
How to rebuild master databse?
How to set database to be read_only in ms sql server?
How to get the definition of a stored procedure back?
What is a periodical index?
What is 'Join' and explain its various types.
How to receive output values from stored procedures?
What are the factors you will check for the performane optimization for a database query?
7 Answers CarrizalSoft Technologies, DELL, SoftSol,
Oracle (3253)
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)