can unique key column accept multiple null value

Question

Hi friends.
Is Unique key accept null value. In my application it does not accept multiple null value.but from i studied it accept null for unique column.suppose it accept, how can i modify my unique column table for accepting null value

Advance Thanks

Riddhi Valecha · Answer

Hi.. Incase you want that the table column should accept multiple null values then tick the column - Allow Null and also do not assign any key(primary or unique key) to that column in design time.

Sandeep Singh Shekhawat · Answer

In SQL SERVER: Primary key column does not accept null values But Unique key column can take only one single NULL value not multiple null values in column of sql server database. So please check how can two row will be unique if both have same Null value for a unique column? So we can only have only one null value in unique filed/column.