Question

我是一名技术新手，拥有一个带有.MDB（MS-Access）数据库的ColdFusion网站，该数据库由我的托管服务新转换为MySQL。在转换为MySQL之后，过去完美工作多年的查询不再有效，并抛出错误消息＆＃34;每个派生表必须有自己的别名＆＃34;。

作为帮助，这是查询的作用 - 并且到目前为止完全完成：我有一个会员数据库。每个成员最多有四个电子邮件地址，因此每个记录的数据库中有四列，每个电子邮件地址与电子邮件服务提供商域（Comcast.net，gmail.com，aol.com等）相关联。我使用查询结果单独列出所有电子邮件域，其中包含与每个电子邮件地址关联的成员电子邮件地址总数（Comcast.net 12，gmail.com 26，aol.com 13等）。

我需要在此查询中进行最低限度的修改才能使其与MySQL一起使用？谢谢你的帮助！

<cfquery name="cfqGetEmailServiceProviderDomains" datasource="membership_database">
SELECT email_service_provider, COUNT(email_service_provider) AS Instances
FROM
(
    SELECT MID(email_address1, INSTR(email_address1, '@') + 1) AS email_service_provider
    FROM tblMembers
    WHERE email_address1_active = 1 
    AND email_address1 IS NOT NULL
    UNION ALL
    SELECT MID(email_address2, INSTR(email_address2, '@') + 1) AS email_service_provider
    FROM tblMembers
    WHERE email_address2_active = 1 
    AND email_address2 IS NOT NULL
    UNION ALL
    SELECT MID(email_address3, INSTR(email_address3, '@') + 1) AS email_service_provider
    FROM tblMembers
    WHERE email_address3_active = 1 
    AND email_address3 IS NOT NULL
    UNION ALL
    SELECT MID(email_address4, INSTR(email_address4, '@') + 1) AS email_service_provider
    FROM tblMembers
    WHERE email_address4_active = 1 
    AND email_address4 IS NOT NULL
)
GROUP BY email_service_provider
ORDER BY email_service_provider ASC
</cfquery>

Answer 1

尝试在表格中添加别名

SELECT ...
FROM (
...
) table_alias
GROUP BY ...
ORDER BY ...

使用.MDB数据库不能使用MySQL数据库的SQL查询

1 个答案: