我不能让它工作
SELECT PM.PMNUM, (COUNT(ROUTE_STOP.LOCATION) * JOBPLAN.JPDURATION)
FROM PM
LEFT OUTER JOIN ROUTE_STOP ON ROUTE_STOP.ROUTE = PM.ROUTE
LEFT OUTER JOIN JOBPLAN ON JOBPLAN.JPNUM = PM.JPNUM
GROUP BY PM.PMNUM
正如我所见,您的最低限度错过了一个小组。
SELECT PM.PMNUM, (COUNT(ROUTE_STOP.LOCATION) * JOBPLAN.JPDURATION)
FROM PM
LEFT OUTER JOIN ROUTE_STOP ON ROUTE_STOP.ROUTE = PM.ROUTE
LEFT OUTER JOIN JOBPLAN ON JOBPLAN.JPNUM = PM.JPNUM
GROUP BY PM.PMNUM, JOBPLAN.JPDURATION
如果这对您没有帮助,您需要提供进一步的反馈什么不起作用?