使用子查询创建视图的正确语法？答案

【问题标题】：Proper syntax for create view with a subquery?使用子查询创建视图的正确语法？
【发布时间】：2015-04-10 01:14:11
【问题描述】：

我想使用此代码创建视图：

SELECT t1.FirstName, t1.LastName, t2.Sum FROM Customer as t1,(SELECT CustomerID,Sum(Total) as Sum  FROM Invoice GROUP BY(CustomerID)) as t2 WHERE t1.CustomerID=t2.CustomerID

对我来说有意义的方式是做

Create VIEW t2 as SELECT CustomerID,Sum(Total) as Sum  FROM Invoice GROUP BY(CustomerID)

Create VIEW CustomerInvoices as SELECT t1.FirstName, t1.LastName, t2.Sum FROM Customer as t1, t2  WHERE t1.CustomerID=t2.CustomerID

但这给了我一个语法错误，所以我不确定如何调用主视图中的第一个视图

【问题讨论】：

标签： sql phpmyadmin create-view

【解决方案1】：

正如您所注意到的，这种语法在 MySQL 中是不允许的（尽管在其他数据库中是允许的）：

SELECT t1.FirstName, t1.LastName, t2.Sum
FROM Customer as t1 JOIN
     (SELECT CustomerID,Sum(Total) as Sum  FROM Invoice GROUP BY(CustomerID)
     ) t2 
     ON t1.CustomerID = t2.CustomerID;

您可以将其改写为：

SELECT c.FirstName, c.LastName, sum(total) as sum
FROM Customer c JOIN
     Invoice i
     ON c.CustomerID = i.CustomerId
GROUP BY c.FirstName, c.LastName;

这将在视图中起作用。

【讨论】：