Logical Operators

The usual logical operators include AND, OR, and NOT. SQL uses a three-valued logical system with true, false, and null, which represents "unknown". Their priorities are NOT > AND > OR.

Table 1 lists operation rules, where a and b represent logical expressions.

**Table 1** Operation rules
a	b	a AND b Result	a OR b Result	NOT a Result
TRUE	TRUE	TRUE	TRUE	FALSE
TRUE	FALSE	FALSE	TRUE	FALSE
TRUE	NULL	NULL	TRUE	FALSE
FALSE	FALSE	FALSE	FALSE	TRUE
FALSE	NULL	FALSE	NULL	TRUE
NULL	NULL	NULL	NULL	NULL

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

Parent topic: Functions and Operators

Previous topic: Array Functions

Next topic: Comparison Operators

Feedback

Was this page helpful?

Helpful Not helpful

Provide feedback

Thank you very much for your feedback. We will continue working to improve the documentation.See the reply and handling status in My Cloud VOC.

The system is busy. Please try again later.

Which of the following issues have you encountered?

Content is inconsistent with the product UI

Unclear descriptions

Lack of examples or code

Incorrect steps

Can't find what I need

Lack of best practices

Feedback (optional)

0/500

Select at least one type of issue, and enter your comments or suggestions.

Enter a maximum of 500 characters.

Submit Cancel

For any further questions, feel free to contact us through the chatbot.

Chatbot