mysql反向索引

-- 创建一个自定义函数来反转字符串
DELIMITER $$
CREATE FUNCTION ReverseString(str VARCHAR(255)) RETURNS VARCHAR(255)
BEGIN
    DECLARE reversed VARCHAR(255);
    SET reversed = '';
    DECLARE i INT DEFAULT LENGTH(str);
    WHILE i > 0 DO
        SET reversed = CONCAT(SUBSTRING(str, i, 1), reversed);
        SET i = i - 1;
    END WHILE;
    RETURN reversed;
END$$
DELIMITER ;

-- 创建表并使用自定义函数创建反向索引
CREATE TABLE example (
    id INT PRIMARY KEY,
    name VARCHAR(255),
    INDEX (ReverseString(name))
);

-- 插入数据
INSERT INTO example (id, name) VALUES (1, 'example');
INSERT INTO example (id, name) VALUES (2, 'test');

-- 查询数据
SELECT * FROM example WHERE ReverseString(name) = ReverseString('example');