书写案例陈述错误ORA-00923

Question

我有一个使用CREATE和INSERT语句填充的数据库。我现在正在尝试编写一个案例状态集，它将显示“客户”，其payment_due_date已经超过了今天的日期。下面是下面的代码

创建语句'Ord'(Order)

CREATE TABLE Ord(OrderID varchar2(9) PRIMARY KEY, 
CustomerID varchar(9) REFERENCES Customer(CustomerID), 
Expected_Delivery_Date date DEFAULT sysdate NOT NULL, 
Actual_Delivery_Date date DEFAULT sysdate NOT NULL, 
Payment_Due_Date date DEFAULT sysdate NOT NULL,
 Order_Date date DEFAULT sysdate NOT NULL, Price Varchar(10), 
Order_Placed varchar2(1) CONSTRAINT OrderPlaced 
CHECK(Order_Placed IN('Y','N')) NOT NULL, Order_Confirmed varchar2(1)
CONSTRAINT Order_Confirmed CHECK(Order_Confirmed IN('Y','N')) 
NOT NULL, Order_Completed varchar2(1) CONSTRAINT Order_Completed
CHECK(Order_Completed IN('Y','N')) NOT NULL) 

插入语句

 INSERT INTO Ord VALUES(401565981, 501623129, 
    '10-Dec-10', '11-Dec-10', '07-Dec-10', '03-Dec-10','£14.99', 'Y', 'Y', 'Y')

CASE语句

 SELECT OrderID, CustomerID, Payment_Due_Date CASE WHEN 
Payment_Due_Date = '08-Dec-10' THEN 'Send Final Demand Letter'
    ELSE 'Do not send letter' 
    END FROM Ord;

当我试图运行上述case语句时，会收到以下错误

ORA- 00923 : FROM关键字找不到预期的00923。00000 -“从预期中找不到的关键字”*原因：

*行动:行处错误: 26栏: 50

有什么办法绕过这件事吗？

Answer 1

我想你需要在Payment_Due_Date和CASE之间加上一个逗号。