Zoho Analytics中MySQL查询报错排查：误用保留字'USER'

作为SQL新手，在Zoho Analytics中编写多表关联查询生成报表用的查询表，源表数据已填充，但执行查询时收到不支持的错误提示，无输出结果。排查后确认是误用了SQL保留字USER作为表别名导致的问题。

原查询代码 #

SELECT
         SITE."name" as 'Site Name',
         SESSION."Id" as 'Session ID',
         SESSION."userId" as 'User ID',
         SESSION."status" as 'Status',
         SESSION."chargePointId" as 'ChargePoint ID',
         SESSION."amount" as "Value",
         SESSION."Calc - Energy [kWh]" as 'Energy',
         SESSION."Calc - Start Datetime" as 'Start',
         SESSION."Calc - End Datetime" as 'End',
         SESSION."Calc - Session Duration" as 'Session Duration',
         SESSION."Calc - Est. Charge Duration" as 'Charge Duration',
         SESSION."reason" as 'Termination Reason',
         CHARGER."tags_0" as 'Tags'
FROM "Sessions Table" AS  SESSION
JOIN "Chargers Table" AS  CHARGER ON SESSION."chargePointId" = CHARGER."id"
JOIN "Sites Table" AS  SITE ON CHARGER."locationId"  = SITE."id"
JOIN "Partners Table" AS PARTNER ON CHARGER."ownerPartnerID" = PARTNER."id"
JOIN "Users Table" AS USER ON SESSION."userID" = USER."id"
ORDER BY 'Session ID' DESC 

Zoho Analytics返回的错误信息 #

错误详情：
您的SQL查询在Zoho Analytics中不被支持。如果您想将此报告为bug，请将查询的截图发送至support@zohoanalytics.com。

问题原因及修正方案 #

USER是SQL的保留字，不能直接用作表别名。只需将JOIN "Users Table" AS USER中的别名USER替换为非保留字（比如USR）即可解决问题。

修正后的查询代码 #

SELECT
         SITE."name" as 'Site Name',
         SESSION."Id" as 'Session ID',
         SESSION."userId" as 'User ID',
         SESSION."status" as 'Status',
         SESSION."chargePointId" as 'ChargePoint ID',
         SESSION."amount" as "Value",
         SESSION."Calc - Energy [kWh]" as 'Energy',
         SESSION."Calc - Start Datetime" as 'Start',
         SESSION."Calc - End Datetime" as 'End',
         SESSION."Calc - Session Duration" as 'Session Duration',
         SESSION."Calc - Est. Charge Duration" as 'Charge Duration',
         SESSION."reason" as 'Termination Reason',
         CHARGER."tags_0" as 'Tags'
FROM "Sessions Table" AS  SESSION
JOIN "Chargers Table" AS  CHARGER ON SESSION."chargePointId" = CHARGER."id"
JOIN "Sites Table" AS  SITE ON CHARGER."locationId"  = SITE."id"
JOIN "Partners Table" AS PARTNER ON CHARGER."ownerPartnerID" = PARTNER."id"
JOIN "Users Table" AS USR ON SESSION."userID" = USR."id"
ORDER BY 'Session ID' DESC 

内容的提问来源于stack exchange，提问作者chargeTheWorld