Question

Consider the given boolean expression:
$Exp:a\ge 98ANDNOT(b\le 30)$
For what values of a and b including NULL the Exp have truth value UNKNOWN is SQL. Consider these statements regarding above conditions:
$I.\text{b is NULL and}a\ge 98$
II. a is NULL and b >30
Which of the above statements is/are correct?

Answer 1

(c)
$\bullet$ The AND evaluates to UNKNOWN $\left(x_{1}AND{x}_2\right)$
$willbeneither\left(x_{1}nor{x}_2\right)isFALSE.$

$\bullet$ So both the statement results is UNKNOWN.