SQL语句的练习

select lastName ,firstName from Persons
select *from Persons order by Birthday desc
select *from Persons where city = 'Sandnes'
select *from Persons where firstName ='Ola' and LastName ='HanSen'
select *from Persons  where  firstName ='Ola' or LastName='Svendson'
select *from Persons  where (firstName ='Ola' or firstName ='Tova') and City ='Sandnes'
select *from Persons where LastName not between 'HanSen' and 'Pettesson'
select distinct city from Persons  

select CompanyName , sum(Amount)  from tbl_Company  group by CompanyName HAVING SUM(Amount)>7000

select Employees.Name ,Orders.Product From Employees,orders where Employees.id= orders.id

select Employees.name,Orders.Product from Employees inner join orders on employees.id = orders.id
select Employees.name ,Orders.Product from Employees left join orders on employees.id = orders.id
select employees.name ,orders.product from employees right join orders on employees.id = orders.id
select firstName as Family,firstName as Name from Persons
select lastName ,firstName from Persons as Employees
insert into Employees(Name) values('林丹') 
insert into Employees values('111')
update Persons set firstName ='TTOC' where lastName ='HanSen'

alter table Classmates add nation  varchar(100)
alter table Classmates drop column nation
drop table Classmates

create database NewDatabase
drop database NewDatabase
select count(Amount) from tbl_Company
select sum(Amount) from tbl_Company
select avg(Amount) from tbl_Company
select max(Amount) from tbl_Company
select min(Amount) from tbl_Company