update

app/service/chatroom.js

@@ -18,7 +18,7 @@ class ChatroomService extends CrudService {
     assert(teacher, '缺少教师姓名');
     assert(studentid, '缺少学生id');
     assert(student, '缺少学生姓名');
-    const res = await this.model.find({ teacherid, teacher, studentid, student });
+    const res = await this.model.findOne({ teacherid, teacher, studentid, student });
     if (res) return res;
     const cres = await this.model.create({ teacherid, teacher, studentid, student });
     return cres;