正在编写 mysql 程序

Question

我 table:

name position rating try_count
Bob    87       15      20
Erick 115       46      28
John   95       32      17
Karl  208       25       5

我们需要编写一个存储过程来计算最有效率的球员的名字。使用公式 (position / try_count) * rating 计算效率。获得的数字越高，玩家的效率就越高。先决条件：必须使用循环(while) 和临时table 执行计算。我不知道该怎么做，Google 也帮不了我:(

谢谢大家！

Answer 1

这是一些符合您规定要求的代码。

DROP TABLE IF EXISTS T;
DROP PROCEDURE IF EXISTS P;
CREATE TABLE T
(name VARCHAR(10),position INT,rating INT,try_count INT);
INSERT INTO T VALUES
('Bob'   , 87     ,  15   ,   20),
('Erick' ,115     ,  46   ,   28),
('John'  , 95     ,  32   ,   17),
('Karl'  ,208     ,  25   ,    5);

delimiter $$
create procedure p()
begin
    declare i int;
    set i = 1;
    drop temporary table if exists temp;
    create temporary table temp as 
        select *,
                 (position / try_count) * rating as performance
        from t;
        while I = 1 do
            select * from temp order by performance desc limit 1;
            set i = 2;
        end while;
end  $$

delimiter ;

call p();

+------+----------+--------+-----------+-------------+
| name | position | rating | try_count | performance |
+------+----------+--------+-----------+-------------+
| Karl |      208 |     25 |         5 |   1040.0000 |
+------+----------+--------+-----------+-------------+
1 row in set (0.048 sec)

当然是废话..

正在编写 mysql 程序

Writing mysql procedure

mysql

stored-procedures