mysql 按长度分隔

DELIMITER //

CREATE FUNCTION SplitStringByLength(str VARCHAR(255), len INT)
RETURNS VARCHAR(255) DETERMINISTIC
BEGIN
    DECLARE result VARCHAR(255) DEFAULT '';
    DECLARE currentPos INT DEFAULT 1;
    DECLARE subStr VARCHAR(255);

    WHILE currentPos <= LENGTH(str) DO
        SET subStr = SUBSTRING(str, currentPos, len);
        SET result = CONCAT(result, subStr, '|');
        SET currentPos = currentPos + len;
    END WHILE;

    RETURN SUBSTRING(result, 1, LENGTH(result) - 1);
END //

DELIMITER ;

SELECT SplitStringByLength(content, 5) AS split_content FROM test_table;

split_content
----------------
Hello|World|ThisI|sATe|st