练习1
2022-08-07
1,liuyan
2,tangyan
3,jinlian
4,dalang
5,ximenqing
2022-08-08
1,liuyan
2,tangyan
4,dalang
6,wusong
-- 创建分区表记录每天用户登陆信息
create table tb_login
(
uid int,
name string
) partitioned by (dt string)
row format delimited fields terminated by ",";
load data local inpath '/root/2022-08-07' into table tb_login partition (dt = '2022-08-07');
load data local inpath '/root/2022-08-08' into table tb_login partition (dt = '2022-08-08');
select *
from tb_login;
-- 查询7号和8号都登陆人的信息
select t1.uid, t1.name
from (select * from tb_login where dt = '2022-08-07') t1
join
(select * from tb_login where dt = '2022-08-08') t2
on t1.uid = t2.uid;
-- 查询7号登陆 8号没登录人的信息
select *
from (select * from tb_login where dt = '2022-08-07') t1
left join
(select * from tb_login where dt = '2022-08-08') t2
on t1.uid = t2.uid
where t2.uid is null;
-- 查询8号登陆 7号没登陆人的信息
select t2.*
from (select * from tb_login where dt = '2022-08-07') t1
right join
(select * from tb_login where dt = '2022-08-08') t2
on t1.uid = t2.uid
where t1.uid is null;
-- 查询7号登陆 8号没登陆 和 8号登陆 7号没登陆人的信息
select *
from (select * from tb_login where dt = '2022-08-07') t1
full join
(select * from tb_login where dt = '2022-08-08') t2
on t1.uid = t2.uid
where t1.uid is null
or t2.uid is null;
练习2
建表准备数据
vi mark.txt
liuyan,语文,100
liuyan,数学,99
liuyan,英语,100
tangyan,语文,80
tangyan,数学,98
tangyan,英语,60
create table stu_mark
(
sname string,
subject string,
score double
) row format delimited fields terminated by ",";
load data local inpath '/root/mark.txt' into table stu_mark;
select * from stu_mark;
-- 使用case when 查询每个人的语文成绩
SELECT sname, case subject WHEN '语文' THEN score else 0 END as `语文` FROM stu_mark ;
-- 查询每个人的每科成绩
SELECT sname,
case subject WHEN '语文' THEN score else 0 END as `语文`,
case subject WHEN '数学' THEN score else 0 END as `数学`,
case subject WHEN '英语' THEN score else 0 END as `英语`
FROM stu_mark ;
-- 得到最终结果
SELECT sname,
max(case subject WHEN '语文' THEN score else 0 END) as `语文`,
max(case subject WHEN '数学' THEN score else 0 END) as `数学`,
max(case subject WHEN '英语' THEN score else 0 END) as `英语`
FROM stu_mark group by sname;
练习3
yg.txt
uid,name,age,gender
1,liuyan,23,M
2,tangyan,33,F
3,jinlian,28,M
4,dalang,37,F
5,ximenqing,17,M
bm.txt
bid,bname
1,财务部
2,销售部
3,后勤部
4,技术部
gz.txt
uid,jb,jj,tc,bid
1,2000,3000,5000,1
2,1000,4000,1000,2
3,5000,1000,5000,1
4,4000,300,7000,3
-- 创建员工表
create table yg
(
uid int,
name string,
age int,
gender string
)
row format delimited fields terminated by ',';
-- 加载员工数据
load data local inpath '/root/yg.txt' into table yg;
-- 创建部门表
create table bm
(
bid int,
bname string
)
row format delimited fields terminated by ',';
-- 加载部门数据
load data local inpath '/root/bm.txt' into table bm;
-- 创建工资表
create table gz
(
uid int,
jb double,
jj double,
tc double,
bid int
)
row format delimited fields terminated by ',';
-- 加载工资数据
load data local inpath '/root/gz.txt' into table gz;
select * from yg;
select * from gz;
select * from bm;
1.查询每个部门的员工数 男员工个数 女员工个数 显示部门名称
-- 查询每个员工的 工号 姓名 性别 部门id 部门名称.
select yg.uid,
yg.name,
yg.gender,
bm.bid,
bm.bname
from yg
inner join gz on yg.uid = gz.uid
inner join bm on gz.bid = bm.bid;
-- 查询每个部门的总人数 部门名称 部门总人数
with t1 as (select yg.uid,
yg.name,
yg.gender,
bm.bname
from yg
inner join gz on yg.uid = gz.uid
inner join bm on gz.bid = bm.bid)
select t1.bname,
count(bname) `总人数`
from t1
group by t1.bname;
-- 查询每个部门的总人数 部门名称 部门总人数 男员工个数 女员工个数
with t1 as (select yg.uid,
yg.name,
yg.gender,
bm.bname
from yg
inner join gz on yg.uid = gz.uid
inner join bm on gz.bid = bm.bid)
select t1.bname,
count(bname) `总人数`,
sum(`if`(gender = 'M', 1, 0)) `男`,
sum(`if`(gender = 'F', 1, 0)) `女`
from t1
group by t1.bname;
------------------------------------------------------------------------------------------------
-- 查询 每个部门的总人数 男员工个数 女员工个数
select bid,
count(bid) total_num,
sum(`if`(gender = 'M', 1, 0)) nan,
sum(`if`(gender = 'F', 1, 0)) nv
from yg
inner join gz on yg.uid = gz.uid
group by bid;
-- 显示部门名称
with t1 as (select bid,
count(bid) total_num,
sum(`if`(gender = 'M', 1, 0)) nan,
sum(`if`(gender = 'F', 1, 0)) nv
from yg
inner join gz on yg.uid = gz.uid
group by bid)
select bm.bname, t1.*
from t1
inner join bm on t1.bid = bm.bid;
+-----------+---------+---------------+---------+--------+
| bm.bname | t1.bid | t1.total_num | t1.nan | t1.nv |
+-----------+---------+---------------+---------+--------+
| 财务部 | 1 | 2 | 2 | 0 |
| 销售部 | 2 | 1 | 0 | 1 |
| 后勤部 | 3 | 1 | 0 | 1 |
+-----------+---------+---------------+---------+--------+
2.查询每种性别的总工资
-- 查询每个员工的工资 工号 姓名 性别 基本工资 奖金 提成
select yg.uid,
yg.name,
gz.jb,
gz.jj,
gz.tc
from yg
left join gz on yg.uid = gz.uid;
-- 查询每个员工的总工资 工号 姓名 性别 总工资
select yg.uid,
yg.name,
yg.gender,
(gz.jb + gz.jj + gz.tc) sal
from yg
left join gz on yg.uid = gz.uid;
-- 查询每种性别的总工资
select yg.gender,
sum(gz.jb + gz.jj + gz.tc) total_sal
from yg
left join gz on yg.uid = gz.uid
group by gender;
with t1 as (select yg.uid,
yg.name,
yg.gender,
(gz.jb + gz.jj + gz.tc) sal
from yg
left join gz on yg.uid = gz.uid)
select gender, sum(sal)
from t1
group by gender;
+------------+------------+
| yg.gender | total_sal |
+------------+------------+
| F | 17300.0 |
| M | 21000.0 |
+------------+------------+
3.查询每个员工的中文性别,年龄阶段
-- 查询每个员工信息 及 中文性别
-- if
select *, if(gender == 'M', '男', '女') as ch_gender
from yg;
-- case when 第一种格式
select *,
case gender
when 'M' then '男'
else '女' end as ch_gender
from yg;
-- case when 第二种格式
select *,
case
when gender == 'M' then '男'
else '女' end as ch_gender
from yg;
-- 查询每个员工信息 及 年龄阶段
-- if
select *,
if(age >= 10 and age <= 20, '10~20',
if(age > 20 and age <= 30, '20~30', if(age > 30 and age <= 40, '30~40', 'other'))) as age_stage
from yg;
-- case when
select *,
case
when age >= 10 and age < 20 then '10~20'
when age >= 20 and age < 30 then '20~30'
when age >= 30 and age < 40 then '30~40'
else 'other'
end as age_stage
from yg;
-- 查询每个员工信息 中文性别 年龄阶段
select *,
if(gender == 'M', '男', '女') as ch_gender,
case
when age >= 10 and age < 20 then '10~20'
when age >= 20 and age < 30 then '20~30'
when age >= 30 and age < 40 then '30~40'
else 'other'
end as age_stage
from yg;
with t1 as (select *, if(gender == 'M', '男', '女') as ch_gender from yg)
select *,
case
when age >= 10 and age < 20 then '10~20'
when age >= 20 and age < 30 then '20~30'
when age >= 30 and age < 40 then '30~40'
else 'other'
end as age_stage
from t1;
4.查询每个年龄段的总工资
-- 年龄段 总工资
select t1.age_stage,
sum(gz.jb + gz.jj + gz.tc)
from (select *,
case
when age >= 10 and age < 20 then '10~20'
when age >= 20 and age < 30 then '20~30'
when age >= 30 and age < 40 then '30~40'
else 'other'
end as age_stage
from yg) t1
left join gz
on t1.uid = gz.uid
group by t1.age_stage;
-- cte
with t1 as (select *,
case
when age >= 10 and age < 20 then '10~20'
when age >= 20 and age < 30 then '20~30'
when age >= 30 and age < 40 then '30~40'
else 'other'
end as age_stage
from yg)
select t1.age_stage, sum(gz.jb + gz.jj + gz.tc)
from t1
left join gz
on t1.uid = gz.uid
group by t1.age_stage;
+---------------+----------+
| t1.age_stage | _c1 |
+---------------+----------+
| 10~20 | NULL |
| 20~30 | 21000.0 |
| 30~40 | 17300.0 |
+---------------+----------+
5 求每个人名字工资组成部分中占比最高的工资类型
-- 查询工资表中 每个人 基本工资 奖金 提成 中的最高工资是多少
select *,
greatest(jb, jj, tc) max_sal
from gz;
-- 查询工资表中 每个人 基本工资 奖金 提成 最多的 是哪种类型
select *,
greatest(jb, jj, tc) max_sal,
case
when greatest(jb, jj, tc) == jb then 'jb'
when greatest(jb, jj, tc) == jj then 'jj'
when greatest(jb, jj, tc) == tc then 'tc'
end as max_type
from gz;
select *,
greatest(jb, jj, tc) max_sal,
case greatest(jb, jj, tc)
when jb then 'jb'
when jj then 'jj'
when tc then 'tc'
end as max_type
from gz;
-- 查询每个员工的 工号 姓名 最高工资类型及多少
with t1 as (select *,
greatest(jb, jj, tc) max_sal,
case
when greatest(jb, jj, tc) == jb then 'jb'
when greatest(jb, jj, tc) == jj then 'jj'
when greatest(jb, jj, tc) == tc then 'tc'
end as max_type
from gz)
select yg.uid,
yg.name,
t1.max_sal,
t1.max_type
from yg
left join t1
on yg.uid = t1.uid;
+---------+------------+-------------+--------------+
| yg.uid | yg.name | t1.max_sal | t1.max_type |
+---------+------------+-------------+--------------+
| 1 | liuyan | 5000.0 | tc |
| 2 | tangyan | 4000.0 | jj |
| 3 | jinlian | 5000.0 | jb |
| 4 | dalang | 7000.0 | tc |
| 5 | ximenqing | NULL | NULL |
+---------+------------+-------------+--------------+