大数据-MySQL练习题1

1. 组合两个表

需求：编写一个 SQL 查询，对两表进行关联，展示列为： FirstName, LastName, City, State

展示效果：

FirstName	LastName	City	State
Allen	Wang	New York City	New York

    

Create table Person (PersonId int, FirstName varchar(255), LastName varchar(255));

Create table Address (AddressId int, PersonId int, City varchar(255), State varchar(255));

insert into Person (PersonId, LastName, FirstName) values (1, 'Wang', 'Allen');
insert into Address (AddressId, PersonId, City, State) values (1, 1, 'New York City', 'New York');

最终SQL:

select
     p.FirstName,
     p.LastName,
     a.City,
     a.State
from 
     Person as p 
left join 
     Address as a 
on 
     p.PersonId = a.PersonId;