MySQL - 存储过程 - 仅使用 while 循环获取最后一条记录

Question

我试图继续添加表中的所有价格值。我努力了n_total_price = n_total_price + d_price；

这是一项作业，我必须使用存储过程

它只是给我最后一条记录

    DELIMITER $$
    CREATE PROCEDURE P_TOTAL_PRICES(OUT N_TOTAL_PRICE DECIMAL(30,2))
    BEGIN
        DECLARE D_PRICE DECIMAL(30,2);
        DECLARE ABC DECIMAL(30,2);
        DECLARE FOUND BOOLEAN;
        DECLARE CURSOR_1 CURSOR FOR SELECT PRICE FROM PRODUCT;
        DECLARE CONTINUE HANDLER FOR NOT FOUND SET FOUND = FALSE;
        SET FOUND = TRUE;
        OPEN CURSOR_1;
        FETCH CURSOR_1 INTO ABC;
        WHILE FOUND DO 
            SET N_TOTAL_PRICE = N_TOTAL_PRICE + D_PRICE;
            FETCH CURSOR_1 INTO ABC;
        END WHILE;
        CLOSE CURSOR_1;
    END; $$

Answer 1

DELIMITER $$
CREATE PROCEDURE P_TOTAL_PRICES(OUT N_TOTAL_PRICE DECIMAL(30,2))
BEGIN
DECLARE D_PRICE DECIMAL(30,2);
DECLARE ABC DECIMAL(30,2);
DECLARE FOUND BOOLEAN;
DECLARE CURSOR_1 CURSOR FOR SELECT PRICE FROM PRODUCT;
DECLARE CONTINUE HANDLER FOR NOT FOUND SET FOUND = FALSE;
SET FOUND = TRUE;
OPEN CURSOR_1;
FETCH CURSOR_1 INTO ABC;
**SET N_TOTAL_PRICE = 0;**
WHILE FOUND DO SET N_TOTAL_PRICE = N_TOTAL_PRICE +D_PRICE;
FETCH CURSOR_1 INTO ABC;
END WHILE;
CLOSE CURSOR_1;
END; $$