mysql 列转行存储过程

DELIMITER //

CREATE PROCEDURE column_to_row()
BEGIN
    DECLARE done INT DEFAULT FALSE;
    DECLARE col_name VARCHAR(255);
    DECLARE cur CURSOR FOR SELECT column_name FROM information_schema.columns WHERE table_name = 'your_table' AND table_schema = 'your_database';
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN cur;

    read_loop: LOOP
        FETCH cur INTO col_name;
        IF done THEN
            LEAVE read_loop;
        END IF;

        SET @sql = CONCAT('SELECT ', col_name, ' AS column_name FROM your_database.your_table');
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END LOOP;

    CLOSE cur;
END //

DELIMITER ;