需求： 根据成绩表数据，以10分为一个分数段，成绩进行分段统计

思路：1.对成绩除10，然后向下取整，得到区间分组值；

2.根据区间分组值进行分组统计；

1.创建表A，并且插入值

CREATE TABLE A(
    name VARCHAR,
    grade float)
INSERT INTO a VALUES ('a', 90);
INSERT INTO a VALUES ('b', 93);
INSERT INTO a VALUES ('c', 70);
INSERT INTO a VALUES ('d', 80);
INSERT INTO a VALUES ('d', 10);
INSERT INTO a VALUES ('d', 8);
INSERT INTO a VALUES ('d', 100);
INSERT INTO a VALUES ('d', 0);

2.查看表数据

SELECT * from a ;

3.先对数据进行除10向下取整操作

SELECT
    t.con, count (*)FROM
    (        SELECT
            floor((A .grade / 10)) AS con        FROM
            A
    ) TGROUP BY
    T .con;

在对处理数据进行统计

SELECT
    (
        (T .con * 10) || '-' || ((T .con + 1) * 10 - 1)
    ) AS "分数段",    COUNT (*) AS "人数"FROM
    (        SELECT
            FLOOR ((A .grade / 10)) AS con        FROM
            A
    ) TGROUP BY
    T .con