Logical Operators

For logical operators, boolean expressions are specified as operands; TRUE, FALSE or NULL is returned as a result. If a boolean value is used in an arithmetic expression, TRUE is evaluated to 1 and FALSE is evaluated to 0.

Note

As of version 11.2, using a non-logical value (such as an integer or column) as an operand raises the error “operand must be logical expression.” Such a condition must be rewritten with an explicit comparison: a constant condition like WHERE 1 as WHERE 1=1, and a column condition like WHERE column_name as WHERE column_name <> 0.

The following table shows the logical operators.

Logical Operators

Logical Operator	Description	Condition
AND, &&	If all operands are TRUE, it returns TRUE.	a AND b
OR, ||	If none of operands is NULL and one or more operands are TRUE, it returns TRUE. If pipes_as_concat is no that is a parameter related to SQL statements, a double pipe symbol can be used as OR operator.	a OR b
XOR	If none of operand is NULL and each of operand has a different value, it returns TRUE.	a XOR b
NOT, !	A unary operator. If a operand is FALSE , it returns TRUE. If it is TRUE , returns FALSE.	NOT a

Truth Table of Logical Operators

a	b	a AND b	a OR b	NOT a	a XOR b
TRUE	TRUE	TRUE	TRUE	FALSE	FALSE
TRUE	FALSE	FALSE	TRUE	FALSE	TRUE
TRUE	NULL	NULL	TRUE	FALSE	NULL
FALSE	TRUE	FALSE	TRUE	TRUE	TRUE
FALSE	FALSE	FALSE	FALSE	TRUE	FALSE
FALSE	NULL	FALSE	NULL	TRUE	NULL