| 23. 1. 10. Logical Operators |
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PL/SQL has three logical operators: AND, OR, and NOT. |
The NOT operator is typically used to negate the result of a comparison expression. |
The AND and OR operators are typically used to link together multiple comparisons. |
The Syntax for the NOT Operator: |
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boolean_expression can be any expression resulting in a boolean, or true/false value. |
The Syntax for the AND Operator: |
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boolean_expression AND boolean_expression
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boolean_expression can be any expression resulting in a boolean, or true/false value. |
The AND operator returns a value of true if both expressions each evaluate to true; |
otherwise, a value of false is returned. |
| Expression | Result | | (5 = 5) AND (4 < 10) AND (2 >= 2) | true | | (5 = 7) AND (5 = 5) | false | | 'Mon' IN ('Sun','Sat') AND (2 = 2) | false |
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The Syntax for the OR Operator: |
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boolean_expression OR boolean_expression
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boolean_expression can be any expression resulting in a boolean, or true/false, value. |
The OR operator returns a value of true if any one of the expressions evaluates to true. |
A value of false is returned only if both the expressions evaluate to false. |
| Expression | Result | | (5 <> 5) OR (4 >= 100) OR (2 < 2) | false | | (7 = 4) OR (5 = 5) | true | | 'Mon' IN ('Sun','Sat') OR (2 = 2) | true |
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