sql

create table gsession
(
id char(4),
gtype char(20),
gdate date,
gduration int,
gfee decimal(6,2) check (gfee>=0),
constraint gsessionpk primary key (id)
)

select * from gsession;
drop table gsession;
insert into gsession values('1234','bball','2018-11-11',11,10.20);
insert into gsession values('0934','bball','2018-11-11',11,10.20);
insert into gsession values('9934','bball','2018-11-11',11,10.20);
insert into gsession values('3234','bball','2018-11-11',11,10.20);
insert into gsession values('7534','bball','2018-11-11',11,10.20);
insert into gsession values('7734','bball','2018-11-11',11,10.20);
insert into gsession values('4334','bball','2018-11-11',11,10.20);
insert into gsession values('1734','bball','2018-11-11',11,10.20);
insert into gsession values('1534','bball','2018-11-11',11,10.20);
insert into gsession values('1130','vball','2018-11-11',11,10.20);
insert into gsession values('4330','vball','2018-11-11',11,10.20);
insert into gsession values('1730','vball','2018-11-11',11,10.20);
insert into gsession values('1530','vball','2018-11-11',11,10.20);
insert into gsession values('1030','vball','2018-11-11',11,10.20);


select count(*) 'number of rows' from gsession;
select max(gfee) 'highst value of gfee'from gsession;
select max(gduration) 'highest value of gduration' from gsession where gtype='vball';
select count(*) 'total rows' from gsession group by gtype;
select extract(year from gdate), extract(month from gdate), gtype;
select max(gduration) from gsession;
select * from gsession where gduration = (select max(gduration) from gsession);
select gtype, count(*) 'gcount' from gsession group by gtype;

update gsession
set gtype = 'ping pong', gduration = 10 where id = '1234';

delete from gsession; -- delete everything
delete from gsession where id = '1234';
delete from gsession where gtype = 'bball';

drop table gsession; -- drop