Boolean operators
Vertica supports the following Boolean operators:.
Vertica supports the following Boolean operators:
-
AND -
OR -
NOT
Operators AND and OR are commutative, that is, you can switch left and right operands without affecting the result. However, the order of evaluation of sub-expressions is not defined. To force evaluation order, use a CASE construct.
Caution
Do not confuse Boolean operators with the Boolean predicate or Boolean data type, which can have only two values: true and false.Logic
SQL uses a three-valued Boolean logic where the NULL represents "unknown."
| If a = | and b = | then ... | |
|---|---|---|---|
| a AND b = | a OR b = | ||
| t |
t |
t |
t |
| t |
f |
f |
t |
| t |
NULL |
NULL |
t |
f |
f |
f |
f |
f |
NULL |
f |
NULL |
NULL |
NULL |
NULL |
NULL |
| If a = ... | then NOT a = |
|---|---|
t |
f |
f |
t |
NULL |
NULL |