fix bug

exam-work-api/src/main/java/cn/com/qmth/examcloud/service/examwork/service/ExamStudentService.java

@@ -301,6 +301,7 @@ public class ExamStudentService {
 		}
 		if(examStudent != null){
 			dto.setId(examStudent.getId());
+			dto.setStudentId(examStudent.getStudentId());
 		}
 	}
 

exam-work-domain/src/main/java/cn/com/qmth/examcloud/service/examwork/assembler/ExamStudentAssembler.java

@@ -67,6 +67,7 @@ public class ExamStudentAssembler {
 			domain.setStudentCode(dto.getStudentCode());
 			domain.setInfoCollector(dto.getInfoCollector());
 			domain.setPhone(dto.getPhone());
+			domain.setStudentId(dto.getStudentId());
 		}
 		return domain;
 	}