[LeetCode]-DataBase-Combine Two Tables
Table: Person
+-------------+---------+ | Column Name | Type | +-------------+---------+ | PersonId | int | | FirstName | varchar | | LastName | varchar | +-------------+---------+ PersonId is the primary key column for this table.
Table: Address
+-------------+---------+ | Column Name | Type | +-------------+---------+ | AddressId | int | | PersonId | int | | City | varchar | | State | varchar | +-------------+---------+ AddressId is the primary key column for this table.
Write a SQL query for a report that provides the following information for each person in the Person table, regardless if there is an address for each of those people:
FirstName, LastName, City, State
需求:简单的表连接
查询:sql
CREATE TABLE Person(
PersonId TINYINT UNSIGNED auto_increment PRIMARY KEY,
FirstName varchar(20),
LastName varchar(20)
)ENGINE=MyISAM CHARSET=utf8;
CREATE TABLE Address(
AddressId TINYINT UNSIGNED auto_increment PRIMARY KEY,
PersonId TINYINT UNSIGNED,
City VARCHAR(20),
State VARCHAR(20)
)ENGINE=MyISAM CHARSET=utf8;
SELECT t1.FirstName,t1.LastName,t2.City,t2.State
FROM Person t1
LEFT JOIN Address t2 ON t1.PersonId=t2.PersonId