mysql 创建视图成功，使用时总报错说未知的列名是什么原因？

#创建、使用视图#错误代码： 1054
Unknown column 'u.customerID' in 'field list'
DROP VIEW vw_UCT;

CREATE VIEW vw_UCT
AS
SELECT u.customerID,u.customerName,u.pid,u.telephone,u.address,c.savingID,c.openDate,c.openMoney,c.balance,c.password,t.transDate,t.transType,t.cardID,t.transMoney,t.remark
FROM UserInfo AS u
JOIN CardInfo AS c
ON c.customerID=u.customerID
JOIN TradeInfo AS t
ON t.cardID=c.cardID;

#a输出银行客户记录#
SELECT u.customerID 客户编号,u.customerName 客户名,u.pid 身份证号,u.telephone 电话号码,u.address 居住地址
FROM vw_UCT;