Can we use more than one null value for unique key?
Answer Posted / christina
Yes, We can use more then one null value in unique key ,
because "null" means undefined or unknown so we can add any
number of null values in unique key...
This is the major difference between primary nd unique key,
Primary key doesn't allow null values to be entered into
the columns marked as priamry key and Unique allow us to
enter null values...............
Is This Answer Correct ? | 5 Yes | 2 No |
Post New Answer View All Answers
How does a trigger work?
what is a database lock ? : Sql dba
How bulk collect improves performance?
What is fmtonly in sql?
What is on delete set null?
Which is better cte or subquery?
what are integrity rules?
How can you fetch first 5 characters of the string?
What are the topics in pl sql?
what is denormalization. : Sql dba
What are the different type of joins in sql?
How do I delete a trigger?
Which join is default?
How can we make an if statement within a select statement?
how to select unique records from a table? : Sql dba