SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons INNER JOIN Orders ON Persons.Id_P = Orders.Id_P ORDER BY Persons.LastName
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons,Orders WHERE Persons.Id_P = Orders.Id_P ORDER BY Persons.LastName
是相同的,是内连接的两种写法而已
结果应该是相同的
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo FROM Persons,Orders WHERE Persons.Id_P = Orders.Id_P ORDER BY Persons.LastName
这种方式是不是也是叫内连接
@任冠宇: 这个叫多表查询