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
A. BETWEEN
B. IS NULL
C. LIKE
D. IN
Answer:A
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
A. BETWEEN B. IS NULL C. LIKE D. IN
Explanation:Exists is used to check whether an attribute value is null or not in conjunction with the where clause. 3. A lock that prevents the use of any tables in the database from one transaction while another transaction is being processed is called a