Question

我试图计算医生去的旅行数，并计算通行费需要多少钱。我正在使用ORACLE XE 11g和SQL Developer。我尝试在SELECT中使用相关子查询来做到这一点，但我收到了这条消息：

ORA-00937: not a single-group group function
00937. 00000 -  "not a single-group group function"
*Cause:    
*Action:
Error at Line: 2 Column: 11

这是我谈到的问题：

SELECT person.name, person.surname, COUNT(DISTINCT travelID) AS numberoftravels, 
  (SELECT SUM(costs.cost) FROM costs
    JOIN travel ON costs.travelID = travel.travelID
    JOIN person ON travel.personID = person.personID
    JOIN staff ON travel.personID = staff.staffID
    WHERE stafftype = 'Doctor' AND costtype = 'tolls' and staff1.staffID = person.personID  
  ) AS tollscost

FROM travel JOIN person ON person.personID = travel.personID
  JOIN staff staff1 ON staff1.staffID = person.personID

WHERE stafftype = 'Doctor'
GROUP BY person.name, person.surname;

在添加子查询之前，计数工作正常。有谁知道我为什么会遇到这个问题？

Answer 1

您缺少GROUP BY列 - personID

Oracle SQL相关子查询：不是单组组函数

1 个答案: