15.00 - Nulls and Comparison Operators - Teradata Database

Teradata Database Design

prodname
Teradata Database
vrm_release
15.00
category
User Guide
featnum
B035-1094-015K

Nulls and Comparison Operators

If either operand of a comparison operator is null, then the result is unknown and an error is returned to the requestor. The following examples indicate this behavior.

 

WHEN the expression is …

THEN the result is …

AND this error message returns to the requestor …

5 = NULL

Unknown

3731

5 <> NULL

NULL = NULL

NULL <> NULL

5 = NULL + 5

Note that if the argument of the NOT operator is unknown, the result is also unknown. This evaluation translates to FALSE as a final boolean result.