Question

What operator tests column for absence of data

A)NOT Operator
B) Exists Operator
C) IS NULL Operator
D) None of the above

Answer 1

The IS NULL operator is used in SQL to check for the absence of data in a column, differentiating rows with missing values that are signified by null.

Step-by-step explanation:

This operator is used to find rows where a column does not have a value. In databases, null represents the absence of a value, which is different from an empty string or a zero - it signifies that the data is missing or not applicable. When you want to select rows with missing values in a certain column, you use the IS NULL condition in the WHERE clause of an SQL query.