-- app id号，版本号，下载量
create table app(
app_id int,
version int,
download_count int
);
-- 若干个记录
insert app values
(1,101,10),(1,101,10),
(1,102,5),(1,102,10),
(2,201,10),(2,203,50),
(3,301,10),(3,302,10),
(3,302,50),(3,304,10);
-- 求每个app中下载量最高的那个版本号及其下载总量
create table app(
app_id int,
version int,
download_count int
);
-- 若干个记录
insert app values
(1,101,10),(1,101,10),
(1,102,5),(1,102,10),
(2,201,10),(2,203,50),
(3,301,10),(3,302,10),
(3,302,50),(3,304,10);
-- 求每个app中下载量最高的那个版本号及其下载总量
