mysql去掉左侧

ALTER TABLE users DROP COLUMN id;
ALTER TABLE users DROP COLUMN name;

DELIMITER //

CREATE PROCEDURE DropLeftColumns()
BEGIN
    DECLARE column_name VARCHAR(255);
    DECLARE done INT DEFAULT FALSE;

    -- 假设我们有一个包含要删除的列名的列表
    DECLARE column_list CURSOR FOR SELECT 'id', 'name';
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

    OPEN column_list;

    read_loop: LOOP
        FETCH column_list INTO column_name;
        IF done THEN
            LEAVE read_loop;
        END IF;
        SET @sql = CONCAT('ALTER TABLE users DROP COLUMN ', column_name);
        PREPARE stmt FROM @sql;
        EXECUTE stmt;
        DEALLOCATE PREPARE stmt;
    END LOOP;

    CLOSE column_list;
END //

DELIMITER ;

CALL DropLeftColumns();

CREATE TABLE users_new (
    email VARCHAR(255),
    phone VARCHAR(255),
    address VARCHAR(255)
);

INSERT INTO users_new (email, phone, address)
SELECT email, phone, address FROM users;

DROP TABLE users;

ALTER TABLE users_new RENAME TO users;