Question

我在Microsoft Access 2007中工作的数据库中遇到了CASE语句的某种问题。现在，这是我的问题：

SELECT Email, CASE State
WHEN "NC" THEN "North Carolina"
ELSE "Not Known"
END AS "Origin"
FROM Customers

所有数据对象都有正确的名称，我无法说明为什么查询不会在我的生命中运行。有帮助吗？感谢。

Answer 1

访问权限不支持CASE。对于该示例，您可以使用IIF

SELECT Email,
       IIF(State = "NC", "North Carolina", "Not Known") AS "Origin"
FROM   Customers

如果这是一个减少的示例，您可能需要一个表映射外部联接的状态代码和名称的表。

或者您可以使用SWITCH

SELECT
   Switch(
         State = "NC", "North Carolina",
         State = "SC", "South Carolina"
         True,"Not Known"
         ) AS Origin
FROM   Customers;

Answer 2

您可以使用以下内容执行此操作：

SELECT Email, Iif(State = "NC", "North Carolina", "Not Known") AS "Origin" FROM Customers

您的CASE语句对应于MSSQL语法，该语句被用作Access应用程序的BE数据库。但是Access不支持它。

在SQL中创建案例语句时出现问题

2 个答案: