diff --git a/mnemo_cards_backend/lib/cron/tasks_seeder.dart b/mnemo_cards_backend/lib/cron/tasks_seeder.dart
index c4234b4..38515de 100644
--- a/mnemo_cards_backend/lib/cron/tasks_seeder.dart
+++ b/mnemo_cards_backend/lib/cron/tasks_seeder.dart
@@ -219,35 +219,41 @@ class TasksSeederTask with cron_task.Task {
         ),
       ];
 
-      // Convert UserTaskModel to UserTasksCompanion and insert
-      // PostgreSQL автоматически генерирует UUID через DEFAULT gen_random_uuid()
-      // Используем InsertMode.insertOrIgnore с предопределенными UUID для идемпотентности
+      // Convert UserTaskModel to UserTasksCompanion and insert через DAO
+      // Используем предопределенные UUID для идемпотентности seeder'а
+      int insertedCount = 0;
+      int skippedCount = 0;
+      
       for (final taskData in tasksWithIds) {
         final taskModel = taskData.task;
         final rewardsJson = taskModel.rewards.map((r) => r.toJson()).toList();
         
-        await _db.into(_db.userTasks).insert(
-          UserTasksCompanion.insert(
-            id: Value(taskData.id), // Предопределенный UUID для идемпотентности seeder'а
-            title: taskModel.title,
-            description: taskModel.description,
-            type: taskModel.type,
-            difficulty: taskModel.difficulty,
-            status: taskModel.status,
-            rewards: Value(rewardsJson),
-            createdAt: Value(PgDateTime(taskModel.createdAt)),
-            expiresAt: PgDateTime(taskModel.expiresAt),
-            completedAt: Value(taskModel.completedAt?.let(PgDateTime.new)),
-            proofUrl: Value(taskModel.proofUrl),
-            instructions: Value(taskModel.instructions),
-            tags: Value(taskModel.tags),
-            imageUrl: Value(taskModel.imageUrl),
-          ),
-          mode: InsertMode.insertOrIgnore, // ON CONFLICT DO NOTHING
+        final companion = UserTasksCompanion.insert(
+          id: Value(taskData.id), // Предопределенный UUID для идемпотентности seeder'а
+          title: taskModel.title,
+          description: taskModel.description,
+          type: taskModel.type,
+          difficulty: taskModel.difficulty,
+          status: taskModel.status,
+          rewards: Value(rewardsJson),
+          createdAt: Value(PgDateTime(taskModel.createdAt)),
+          expiresAt: PgDateTime(taskModel.expiresAt),
+          completedAt: Value(taskModel.completedAt?.let(PgDateTime.new)),
+          proofUrl: Value(taskModel.proofUrl),
+          instructions: Value(taskModel.instructions),
+          tags: Value(taskModel.tags),
+          imageUrl: Value(taskModel.imageUrl),
         );
+        
+        final wasCreated = await _db.taskDao.createUserTaskOrIgnore(companion);
+        if (wasCreated) {
+          insertedCount++;
+        } else {
+          skippedCount++;
+        }
       }
 
-      print('Successfully seeded ${tasksWithIds.length} user tasks (duplicates ignored)');
+      print('Successfully seeded user tasks: $insertedCount inserted, $skippedCount skipped (already exist)');
     } catch (e) {
       print('Error seeding tasks: $e');
       rethrow;
diff --git a/mnemo_cards_backend/lib/database/daos/task_dao.dart b/mnemo_cards_backend/lib/database/daos/task_dao.dart
index e5f679d..3087ff5 100644
--- a/mnemo_cards_backend/lib/database/daos/task_dao.dart
+++ b/mnemo_cards_backend/lib/database/daos/task_dao.dart
@@ -82,6 +82,39 @@ class TaskDao extends DatabaseAccessor<AppDatabase> with _$TaskDaoMixin {
     final inserted = await into(db.userTasks).insertReturning(task);
     return inserted.id;
   }
+
+  /// Создать задачу пользователя или игнорировать, если уже существует
+  /// Возвращает true, если задача была создана, false если уже существовала
+  /// 
+  /// Если task.id.present == true, проверяет существование перед вставкой
+  Future<bool> createUserTaskOrIgnore(UserTasksCompanion task) async {
+    // Если ID указан, проверяем существование перед вставкой
+    if (task.id.present) {
+      final existing = await getUserTaskById(task.id.value);
+      if (existing != null) {
+        return false; // Задача уже существует
+      }
+    }
+    
+    try {
+      await into(db.userTasks).insert(
+        task,
+        mode: InsertMode.insertOrIgnore,
+      );
+      return true; // Задача была создана
+    } catch (e) {
+      // PostgreSQL error code 23505 = unique_violation (duplicate key)
+      // Это может произойти в редких случаях race condition
+      final errorString = e.toString();
+      if (errorString.contains('23505') || 
+          errorString.contains('duplicate key') ||
+          errorString.contains('unique constraint')) {
+        return false; // Задача уже существует
+      }
+      // Пробрасываем другие ошибки
+      rethrow;
+    }
+  }
   
   /// Обновить задачу пользователя
   Future<bool> updateUserTask(UserTask task) {
diff --git a/mnemo_cards_backend/lib/database/database.dart b/mnemo_cards_backend/lib/database/database.dart
index db964da..c387660 100644
--- a/mnemo_cards_backend/lib/database/database.dart
+++ b/mnemo_cards_backend/lib/database/database.dart
@@ -179,14 +179,6 @@ class AppDatabase extends _$AppDatabase {
       final result = await customSelect('SELECT 1 as test').getSingle();
       print('Database connection successful: ${result.data}');
       
-      // Удалить constraint valid_email если он существует
-      try {
-        await customStatement('ALTER TABLE users DROP CONSTRAINT IF EXISTS valid_email');
-        print('Removed valid_email constraint if it existed');
-      } catch (e) {
-        print('Warning: Could not remove valid_email constraint: $e');
-      }
-      
       // Включить foreign key constraints
       await customStatement('SET CONSTRAINTS ALL IMMEDIATE');
     },
diff --git a/mnemo_cards_backend/lib/user/user_manager.dart b/mnemo_cards_backend/lib/user/user_manager.dart
index 6a0ecbb..702b4a4 100644
--- a/mnemo_cards_backend/lib/user/user_manager.dart
+++ b/mnemo_cards_backend/lib/user/user_manager.dart
@@ -125,21 +125,28 @@ class UserManager {
 
     print('Creating new user $name $email');
 
-    // Create new user
+    // Create new user with user data in transaction
+    final now = DateTime.now();
     final userCompanion = UsersCompanion.insert(
       externalUserId: externalId,
       name: drift.Value(name),
       email: drift.Value(email),
+      // Explicitly set fields with default values to ensure they're returned by insertReturning
+      admin: drift.Value(false),
+      purchases: drift.Value([]),
+      createdAt: drift.Value(PgDateTime(now)),
+      updatedAt: drift.Value(PgDateTime(now)),
+      isDeleted: drift.Value(false),
     );
 
-    final userId = await _db.userDao.createUser(userCompanion);
+    final userDataCompanion = UserDatasCompanion.insert(
+      userId: '', // Will be set by createUserWithData via copyWith
+      registrationDate: drift.Value(PgDateTime(now)),
+    );
 
-    // Create user data
-    await _db.userDao.createUserData(
-      UserDatasCompanion.insert(
-        userId: userId,
-        registrationDate: drift.Value(PgDateTime(DateTime.now())),
-      ),
+    final userId = await _db.userDao.createUserWithData(
+      user: userCompanion,
+      userData: userDataCompanion,
     );
 
     final user = await _db.userDao.getUserById(userId);