The following table shows the Logical operators supported by PL/SQL. All these operators work on Boolean operands and produce Boolean results. Assume variable A holds true and variable B holds false, then −
| Operator | Description | Examples |
| and | Called the logical AND operator. If both the operands are true then the condition becomes true. | (A and B) is false. |
| or | Called the logical OR Operator. If any of the two operands is true then the condition becomes true. | (A or B) is true. |
| not | Called the logical NOT Operator. Used to reverse the logical state of its operand. If a condition is true then the Logical NOT operator will make it false. | not (A and B) is true. |
Example
DECLARE
a boolean := true;
b boolean := false;
BEGIN
IF (a AND b) THEN
dbms_output.put_line('Line 1 - Condition is true');
END IF;
IF (a OR b) THEN
dbms_output.put_line('Line 2 - Condition is true');
END IF;
IF (NOT a) THEN
dbms_output.put_line('Line 3 - a is not true');
ELSE
dbms_output.put_line('Line 3 - a is true');
END IF;
IF (NOT b) THEN
dbms_output.put_line('Line 4 - b is not true');
ELSE
dbms_output.put_line('Line 4 - b is true');
END IF;
END;
/
When the above code is executed at the SQL prompt, it produces the following result −
Line 2 - Condition is true
Line 3 - a is true
Line 4 - b is not true
PL/SQL procedure successfully completed.