______states that primary keys should not be null:

Related MCQs

• A                  is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.
• With SQL, how can you return the number of not null records in the “Persons” table?
• Which of the following is true regarding Null Value?
• Inorder to simplify the null value confusion in the rank function we can specify
• ANSI-standard SQL allows the use of special operators in conjunction with the WHERE clause. A special operator used to check whether an attribute value is null is
• View the Exhibit and examine the structure of the EMPLOYEES and DEPARTMENTS tables. Which SET operator would you use in the blank space in the following SQL statement to list the departments where all the employees have managers? SELECT department_id FROM departments ____ SELECT department_id FROM employees WHERE manager_id IS NULL;
• How many types of keys in Database Design?
• How many types of keys in Database Design?
• If h is any hashing function and is used to hash n keys in to a table of size m, where n<=m, the expected number of collisions involving a particular key x is :
• How many types of keys in relation database design: