Logical Operators

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Absolute Database supports usual logical operators:

Operator	Description	Example
AND	Both conditions must apply	(ID > 1) AND (ID < 100)
OR	Either condition can apply	(Color = 'Blue') OR (Color = 'Red')
NOT	Logical opposite of condition	NOT (State = 'CA')

SQL uses a three-valued Boolean logic where the null value represents "unknown".
Observe the following truth tables:

a	b	a AND b	a OR b
TRUE	TRUE	TRUE	TRUE
TRUE	FALSE	FALSE	TRUE
TRUE	NULL	NULL	TRUE
FALSE	FALSE	FALSE	FALSE
FALSE	NULL	FALSE	NULL
NULL	NULL	NULL	NULL

            

a	NOT a
TRUE	FALSE
FALSE	TRUE
NULL	NULL

      
The operators AND and OR are commutative, that is, you can switch the left and right operand without affecting the result.