diff --git a/server/src/main/java/ru/mskobaro/tdms/business/service/ParticipantService.java b/server/src/main/java/ru/mskobaro/tdms/business/service/ParticipantService.java
index 825cb37..425bf77 100644
--- a/server/src/main/java/ru/mskobaro/tdms/business/service/ParticipantService.java
+++ b/server/src/main/java/ru/mskobaro/tdms/business/service/ParticipantService.java
@@ -115,6 +115,10 @@ public class ParticipantService {
                 С уважением, администрация.
                 """.formatted(participant.getFullName(), participant.getUser().getUsername(), participantSaveDTO.getUserData().getPassword()));
 
+            if (studentData != null) {
+                studentData.setParticipant(saved);
+            }
+
             if (studentData != null && studentData.getGroup() != null) {
                 List<Defense> defenses = entityManager.createQuery("select distinct d from Defense d inner join fetch d.groups g where g.id = :id", Defense.class)
                         .setParameter("id", studentData.getGroup().getId())
@@ -248,7 +252,6 @@ public class ParticipantService {
         studentData.setMarks3(participantSaveDTO.getStudentData().getMarks3());
 
         studentData = studentDataRepository.save(studentData);
-        studentData.setParticipant(participant);
 
         if (participantSaveDTO.getStudentData().getGroupId() != null) {
             Group group = groupRepository.findByIdThrow(participantSaveDTO.getStudentData().getGroupId());
diff --git a/server/src/main/resources/db/migration/V00000__Initial_schema.sql b/server/src/main/resources/db/migration/V00000__Initial_schema.sql
index adb257d..63c10af 100644
--- a/server/src/main/resources/db/migration/V00000__Initial_schema.sql
+++ b/server/src/main/resources/db/migration/V00000__Initial_schema.sql
@@ -229,9 +229,6 @@ ALTER TABLE participant_role
 ALTER TABLE participant_role
     ADD CONSTRAINT FK_PARROL_ON_ROLE FOREIGN KEY (role_id) REFERENCES role (id) ON DELETE CASCADE ON UPDATE CASCADE;
 
-ALTER TABLE student_data
-    ADD CONSTRAINT UC_STUDENT_DATA_PARTIC UNIQUE (partic_id);
-
 ALTER TABLE student_data
     ADD CONSTRAINT FK_STUDENT_DATA_ON_ADVISER_TEACHER_PARTIC FOREIGN KEY (adviser_teacher_partic_id) REFERENCES participant (id) ON DELETE SET NULL ON UPDATE CASCADE;