2018/04/20
select count(age) from userlist where age between 20 and 30;
select address, name, count(age) from userlist where age between 20 and 30 and address in('tokyo','kyoto');
select address, count(*) from userlist where age between 20 and 30 and address in ('tokyo','kyoto') group by address order by address desc;
\COPY (select address, count(*) from userlist where age between 20 and 30 and address in ('tokyo','kyoto') group by address order by address desc) TO '/home/lisa/data/addressGroup.csv' WITH CSV DELIMITER ',' HEADER ;
select address, count(*), max(age), min(age), avg(age) from userlist group by address;
create view grouplist(address,count,maxage,minage,avgage)
as
select address, count(*), max(age), min(age), avg(age) from userlist group by address;
create view grouplist(address,count,maxage,minage,avgage)
as
select address from userlist where count(*)>=4 group by address;
create view addresslist(address,name)
as
select address, name from userlist;
create view agelist(name, age)
as
select name, age from userlist;
create view futurelist(name,age,age10)
as
select name, age, age+10 from userlist;
select name, age,
case
when age between 20 and 29
then 1
else null
end
from userlist
select name, age,
case
when age between 10 and 19 then 1
when age between 20 and 29 then 2
else null
end
from userlist;
select name, age,
case
when age between 10 and 19 then 1
when age between 20 and 29 then 2
when age between 30 and 39 then 3
else 0
end as flag
from userlist;
select name,address,
case
when address='tokyo' then 1
when address='kyoto' then 2
else 0
end as flag
from userlist;
create view agegroup(name,age,address,flag)
as
select name,age,address,
case
when age between 10 and 19 and address='tokyo' then 1
when age between 10 and 19 and address='kyoto' then 1
when age between 20 and 29 and address<>'tokyo' then 2
else 0
end
from userlist;
create view addressgroup(name,age,flag)
as
select name,age,address,
case
when age between 10 and 19 and address in('tokyo','kyoto') then 1
when age between 20 and 29 and address<>'tokyo' then 2
else 0
end
from userlist;
create view ageaddressview(name,age,address,flag)
as
select name,age,address,
case
when age between 10 and 19 and address in('tokyo','kyoto') then 1
when age between 20 and 29 and address<>'tokyo' then 2
else 0
end
from userlist;
select name,age,address from userlist where age between 10 and 19 and address in('tokyo','kyoto');
create table clublist(
id int,
name varchar(20));
insert into clublist values(1,'music');
insert into clublist values(2,'tenis');
insert into clublist values(3,'baseball');
insert into clublist values(4,'soccer
create view flaglist1(name,age,address,flag)
as
select name,age,address,
case
when age between 10 and 19 and address in('tokyo','kyoto','nagoya') then 1
when age between 20 and 29 and address in('tokyo','kyoto') then 2
when age between 30 and 39 and address in('tokyo','kyoto') then 3
else 4
end
from userlist;
select flag,count(*) from flaglist1 group by flag order by flag;
flag | count
------+-------
1 | 3
2 | 7
3 | 7
4 | 25
(4 rows)
select name, age, address from userlist where age between 20 and 29 and address in('tokyo','kyoto') order by age;
name | age | address
---------+-----+---------
saori | 21 | kyoto
hana | 22 | tokyo
nao | 22 | kyoto
bob | 23 | tokyo
sati | 25 | tokyo
mishima | 25 | tokyo
lulu | 26 | tokyo
(7 rows)
update userlist set address='london' where age between 20 and 29 and address='tokyo';
select address, name from userlist where
address='tokyo' and age between 20 and 29;
name | age | address
-------+-----+---------
saori | 21 | kyoto
nao | 22 | kyoto
(2 rows)
flag | count
------+-------
1 | 3
2 | 2
3 | 7
4 | 30
(4 rows)
select address,cout(*) from userlist group by address;
select * from flaglist1
leftjoin clublist
on flaglist1.flage=clublist.id;
select * from flaglist1
left join clublist on flaglist1.flag=clublist.id ;
insert into clublist values(5,valleyball);
select * from flaglist1 as f left outer join clublist as c on f.flag=c.id;
select * from clublist as c left join flaglist1 as f on c.id=f.flag;
select * from clublist as c left outer join flaglist1 as f on c.id=f.flag;
select * from clublist left outer join flaglist1 on clublist.id=flaglist1.flag;
select *from flaglist1 left outer join clublist on flaglist1.flag=clublist.id;
select id, name from userlist union select id,name from clublist;
create table hobbylist(
id int,
name varchar(20)
);
insert into hobbylist values(1,'soccer');
insert into hobbylist values(2,'cooking');
insert into hobbylist values(3,'music');
insert into hobbylist values(4,'tennis');
insert into hobbylist values(5,'cafe');
select * from hobbylist
select name,age,address, rank() over(order by age) as rank from userlist;
select name, age, address, rank() over(partition by address order by age) as rank from userlist;
git
git init
git status
touch sample.txt
git add sample.txt
git commit sample.txt
git log
git branch
git branch fix1
git checkout fix1
git merge --no-ff fix1
git log --graph
git rest --hard
git reset --hard 3b671699b423a35cead3a8f5cee2d56ec0531bc5
git checkout -
git config --global user.name "testkho"
git config --global user.email "test007@gmail.com"