How to express or in mysql

The OR operator in MySQL is used to check whether at least one of multiple expressions is true. It returns the following results: 1. The OR expression is true if any expression is true. 2. An OR expression is false if all expressions are false. 3. It is used to retrieve records that match multiple criteria.

OR operator in MySQL

OR operator in MySQL (OR ) is used to check whether at least one of two or more expressions is true.

Grammar

##expr1 OR expr2 OR ... OR exprN

where

expr1、expr2, ... and exprN are the expressions to be evaluated.

Result

The OR operator returns the following result:

The OR expression is true if either expression is true.
• The OR expression is false if all expressions are false.

Usage

The OR operator is typically used to retrieve records that match multiple criteria. For example:

SELECT * FROM table_name WHERE column1 = 'value1' OR column2 = 'value2';

This query will return all records where

column1 is equal to value1 or column2 is equal to value2.

Example

-- 检查 column1 是 10 或 column2 是 'foo'
SELECT * FROM table_name WHERE column1 = 10 OR column2 = 'foo';

-- 检查 column1 等于 10 或 column2 不等于 'bar'
SELECT * FROM table_name WHERE column1 = 10 OR column2 <> 'bar';

-- 检查 column1 大于 10 或 column2 为 NULL
SELECT * FROM table_name WHERE column1 > 10 OR column2 IS NULL;

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