Operand should contain 1 column(s)

写sql的时候发生如下错误：

原因是in条件后面有多个字段，应该只能有一个才行；

select student.s,student.sname from student where student.s not in 
(select sc.S from teacher,course,sc where teacher.t = course.t and sc.c = course.C and teacher.tname = '李1');