MySQL_完成组内排序-Oracle中的rank()函数的功用【MySQL教程】,mysql

假定表格为student, 数据以下：

我们要在MySQL中完成Oracle中的rank()函数功用，即组内排序，具体来说：就是对student表中根据课程(course)对门生(name)按分数(score)上下举行排名。

起首新建存储历程realize_rank_in_MySQL，代码以下：

DROP PROCEDURE IF EXISTS realize_rank_in_MySQL;
DELIMITER ;;
CREATE PROCEDURE realize_rank_in_MySQL()
BEGIN
    DECLARE i int;
    SET i = 0;
    WHILE i < (select count(DISTINCT course) from student) DO
            SET @ROW =0;
            INSERT INTO student_rank
            SELECT *, (@ROW:=@ROW+1) AS rank FROM student
            WHERE course=(select DISTINCT course from student limit i,1)
            ORDER BY score DESC;
            set i = i + 1;
    END WHILE;
END
;;
DELIMITER ;

然后输入以下查询语句即可：

drop table if exists student_rank;
create table student_rank like student;
alter table student_rank add rank int;
call realize_rank_in_MySQL;
select * from student_rank;

效果以下：