Question

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 1

Right option is (b) IS NULL

The best I can explain: Exists is used to check whether an attribute value is null or not in conjunction with the where clause.