what is unique key

[priyasp_msit]

unique does not accept duplicate values but accept null values in oracle
but this is different concept for sqlserver why?

only accept one null values after that did not accept more null values
tell me any body

[debasisdas]

Is that the case ?

Different database have different ways of handling NULL.

[chennaprashanth]

Hai Priya,

Unique Key does not accept Duplicate values and it can accept Only ONE NULL value even in SQL Server.

Cheers
Prashanth Chenna,

[ushalakshmi]

Hey priya,

Unique key accept only one Null in sql Server.