创建View Oracle MySQL时出错

Question

Create View ViewA AS

Select o.orderid, o.dishid, o.quantity, o.ordertime, o.deliveryaddress, d.dishid, r.description, r.location, c.firstname, c.lastname, c.phonenumber, c.address, c.city, c.state, c.zip

FROM Orders o

JOIN Dishes d On (o.dishid = d.dishid)

JOIN Customers c ON (o.customerid = c.customerid)

JOIN Restaurants r ON (d.restaurantid = r.restaurantid);

我应该创建一个这样的视图，但我不明白错误：

ORA-00957：重复的列名称 00957. 00000 - ＆＃34;重复列名称＆＃34;

重复的列名称在哪里？

Answer 1

您必须为每列提供别名。

运行：

Create View ViewA AS Select o.orderid ORDER_ID, o.dishid ORDER_DISH_ID, o.quantity ORDER_QUANTITY, o.ordertime ORDER_TIME, o.deliveryaddress DELIVERY_ADDRESS, d.dishid DISH_ID, r.description RES_DESCRIPTION, r.location RES_LOCATION, c.firstname CUST_FIRSTNAME, c.lastname CUST_LASTNAME, c.phonenumber CUST_PHONE, c.address CUST_ADDRESS, c.city CUST_CITY, c.state CUST_STATE, c.zip CUST_ZIP FROM Orders o JOIN Dishes d On (o.dishid = d.dishid) JOIN Customers c ON (o.customerid = c.customerid) JOIN Restaurants r ON (d.restaurantid = r.restaurantid);

Answer 2

您有ItemID和o.dishid - oracle将尝试同时调用d.dishid - 您需要为它们添加别名