SQL-關聯表查詢（連表查詢）

0、例如：select * from T1,T2     where T1.a=T2.a

1、連表查詢 <=> join（inner join）內連接查詢

數據源： 
Persion表： 

 

 Orders表： 

 

 

//使用連表查詢
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo 
FROM Persons,Orders 
WHERE Persons.Id_P = Orders.Id_P

 //使用join查詢 SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons INNER JOIN Orders ON Persons.Id_P = Orders.Id_P ORDER BY Persons.LastName

結果: