使用NOT IN運算符在MySql中選擇的問題？

Question

我已使用以下mysql查詢來選擇所有選定的信息，其中costusinging table中不存在student表的student ID，但遇到錯誤。

有什么幫助嗎？ 提前致謝！

select st.id as 'Student ID', st.stud_fname as 'First Name', st.stud_lname as 'Last Name', st.stud_middle_name as 'Middle Name',
 dp.dep_name as 'Department',dp.max_dur_year as 'Max Duration', st.entry_year as 'Entry',MAX(sc.acc_year) as 'Current Academic Year',  
 sum(sc.Tuition_fee+sc.Accomod_fee+sc.Food_fee) as 'Total Cost Sharing'

from student st left JOIN student_costsharing sc on st.id = sc.stud_id
left join department dp on st.dep_id=dp.id 

 where st.id not in ( SELECT *              
        FROM student_costsharing 
        WHERE sc.stud_id=st.id
               )

GROUP BY st.stud_fname
order by st.stud_fname

錯誤信息：

1241-操作數應包含1列

Answer 1

代替使用*您需要在IN子句中指定列

 where st.id not in ( SELECT stud_id              
        FROM student_costsharing 
        WHERE sc.stud_id=st.id
               )

Answer 2

試試這些，我改變了WHERE NOT IN語句：-

select st.id as 'Student ID', st.stud_fname as 'First Name', st.stud_lname as 'Last Name', st.stud_middle_name as 'Middle Name',
 dp.dep_name as 'Department',dp.max_dur_year as 'Max Duration', st.entry_year as 'Entry',MAX(sc.acc_year) as 'Current Academic Year',  
 sum(sc.Tuition_fee+sc.Accomod_fee+sc.Food_fee) as 'Total Cost Sharing'

from student st left JOIN student_costsharing sc on st.id = sc.stud_id
left join department dp on st.dep_id=dp.id 

 where st.id not in ( SELECT stud_id              
        FROM student_costsharing 
        WHERE sc.stud_id=st.id
               )

GROUP BY st.stud_fname
order by st.stud_fname

Answer 3

問題在於，子查詢的結果集應僅包含一列，因為您無法將where子句的操作數與表的整個結果集進行比較。 應該將哪一列與ID進行比較？

要解決此問題，您需要選擇要與之進行比較的表的一列。