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

Related MCQs

• 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;
• Every time attribute A appears, it is matched with the same value of attribute B, but not the same value of attribute C. Therefore, it is true that:
• The              clause allows us to select only those rows in the result relation of the           clause that satisfy a specified predicate.
• State true or false. i) Select operator is not a unary operator. ii) Project operator chooses subset of attributes or columns of a relation.
• A                  on an attribute of a relation is a data structure that allows the database system to find those tuples in the relation that have a specified value for that attribute efficiently, without scanning through all the tuples of the relation.
• The attribute name could be structured as an attribute consisting of first name, middle initial, and last name. This type of attribute is called
• The attribute name could be structured as an attribute consisting of first name, middle initial, and last name. This type of attribute is called
• In which scenario would you use the ROLLUP operator for expression or columns within a GROUP BY clause?
• SQL applies predicates in the                 clause after groups have been formed, so aggregate functions may be used.
• If you don’t specify ASC or DESC after a SQL ORDER BY clause, the following is used by default ______________