聚合函数和分组(sum(),count(),group by having)

一 ： 创建表

  1  充值表

  

create table recharge         --充值表
(
id int identity(1,1),
account_id  int,         --账号id
player_id   int,         --角色id
player_name   varchar(30),       --角色名
recharge_money int,               --充值金额
recharge_time datetime,   --充值时间
recharge_platform    varchar(30)  --充值平台
)

  2 插入数据

insert into recharge(account_id,player_id,player_name,recharge_money,recharge_time,recharge_platform)values(3,102,'lc',10,'2017-02-12 11:00:00','ios');
insert into recharge(account_id,player_id,player_name,recharge_money,recharge_time,recharge_platform)values(2,101,'xw',100,'2017-02-12 12:00:00','ios');
insert into recharge(account_id,player_id,player_name,recharge_money,recharge_time,recharge_platform)values(1,105,'hc',100,'2017-02-12 10:00:00','ios');
insert into recharge(account_id,player_id,player_name,recharge_money,recharge_time,recharge_platform)values(4,105,'gj',100,'2017-02-11 9:00:00','91');
insert into recharge(account_id,player_id,player_name,recharge_money,recharge_time,recharge_platform)values(4,105,'ww',100,'2017-02-12 19:00:00','91');

二 ：聚合函数和分组的使用

1 查询  2017年2月12号 的充值金额和充值人数

  a 查询语句

select SUM(recharge_money) as money,COUNT(*) as num from recharge
where recharge_time > '2017-02-12 00:00:00' and recharge_time < '2017-02-13 00:00:00'

 b 查询结果



2  查询  2017年2月12号 各个平台的充值金额和充值人数

a  查询语句

select recharge_platform,SUM(recharge_money) as money,COUNT(*) as num from recharge
where recharge_time > '2017-02-12 00:00:00' and recharge_time < '2017-02-13 00:00:00'
group by recharge_platform

b 查询结果



3  查询 2017年2月12日充值人数大于2个人的平台

a 查询语句

select recharge_platform,SUM(recharge_money) as money,COUNT(*) as num from recharge
where recharge_time > '2017-02-12 00:00:00' and recharge_time < '2017-02-13 00:00:00'
group by recharge_platform
having COUNT(*)>2

b 查询结果



4 统计每天每个平台的充值情况

1 查询语句

SELECT recharge_platform,CONVERT(varchar(100), recharge_time, 23) as 'recharge_time',SUM(recharge_money) as recharge_money from recharge
group by recharge_platform, CONVERT(varchar(100), recharge_time, 23)

2 查询结果