相关疑难解决方法(0)

为简单起见,假设所有相关字段都是NOT NULL.

你可以做:

SELECT
    table1.this, table2.that, table2.somethingelse
FROM
    table1, table2
WHERE
    table1.foreignkey = table2.primarykey
    AND (some other conditions)

要不然:

SELECT
    table1.this, table2.that, table2.somethingelse
FROM
    table1 INNER JOIN table2
    ON table1.foreignkey = table2.primarykey
WHERE
    (some other conditions)

这两个是以同样的方式工作MySQL吗？

查询之间有什么区别

SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons
INNER JOIN Orders
ON Persons.P_Id=Orders.P_Id
ORDER BY Persons.LastName

还有这个

SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons, Orders
WHERE Persons.P_Id=Orders.P_Id
ORDER BY Persons.LastName

SELECT * FROM `groupon-spain-6sep-2011`, `Hoja1`,`GroupaliaJuly2011` 
WHERE `groupon-spain-6sep-2011`.`code`= 5654 
    OR  `Hoja1`.`code` = "5654 
    OR `GroupaliaJuly2011`.`code` = 5654

有没有办法在SQL Server中进行oracle样式连接？

select * 
from t1, t2
where t1.id = t2.id (+)

编辑

为什么最好使用"左外连接"和"内连接"类型？我发现阅读旧表单更容易,特别是如果涉及复杂的表连接.