我怎样才能修复这个计数报告，在预期的地方找不到 FROM 关键字

Question

我正在尝试创建一个 sql 语句

 SELECT   ACTIVITY_ID, ACTIVITY_DESCRIPTION,

我选择了任务 activity 因为它将 4 个表连接在一起

 COUNT(*) NAME AS NAMECount

我用上面的count语句来统计志愿者的人数

 DESCRIPTION AS TASK
 FROM

这是内部联接

 TASK_ACTIVITY
 INNER JOIN
 VOLUNTEER ON VOLUNTEER.VOLUNTEER_ID = TASK_ACTIVITY.VOLUNTEER_ID
 INNER JOIN
 TASK ON TASK.TASK_ID = TASK_ACTIVITY.TASK_ID
 GROUP BY VOLUNTEER.NAME;

我收到这个错误

ORA-00923: FROM keyword not found where expected

Answer 1

您可以使用以下查询。在列名中提供别名并按列分组以使其工作，因为您没有提到哪个列属于 table

SELECT   ACTIVITY_ID,
 ACTIVITY_DESCRIPTION,
COUNT(*), NAME AS NAMECount,
 DESCRIPTION AS TASK
 FROM TASK_ACTIVITY TASK_ACTIVITY
 INNER JOIN
 VOLUNTEER VOLUNTEER 
ON VOLUNTEER.VOLUNTEER_ID = TASK_ACTIVITY.VOLUNTEER_ID
 INNER JOIN
 TASK ON TASK.TASK_ID = TASK_ACTIVITY.TASK_ID
 GROUP BY ACTIVITY_ID, ACTIVITY_DESCRIPTION, TASK, VOLUNTEER.NAME;