update unique letter number

internal/repository/letter_outgoing_repository.go

@@ -41,6 +41,25 @@ func (r *LetterOutgoingRepository) Get(ctx context.Context, id uuid.UUID) (*enti
 	return &e, nil
 }
 
+func (r *LetterOutgoingRepository) GetByReferenceNumber(ctx context.Context, refNumber *string) (*entities.LetterOutgoing, error) {
+	db := DBFromContext(ctx, r.db)
+	var e entities.LetterOutgoing
+	if err := db.WithContext(ctx).
+		Preload("Priority").
+		Preload("ReceiverInstitution").
+		Preload("Creator").
+		Preload("ApprovalFlow").
+		Preload("Recipients").
+		Preload("Attachments").
+		Preload("Approvals.Step").
+		Preload("Approvals.Approver").
+		Where("reference_number = ? AND deleted_at IS NULL", refNumber).
+		First(&e).Error; err != nil {
+		return nil, err
+	}
+	return &e, nil
+}
+
 func (r *LetterOutgoingRepository) Update(ctx context.Context, e *entities.LetterOutgoing) error {
 	db := DBFromContext(ctx, r.db)
 	return db.WithContext(ctx).Model(&entities.LetterOutgoing{}).Where("id = ? AND deleted_at IS NULL", e.ID).Updates(e).Error

internal/repository/letter_repository.go

@@ -29,6 +29,17 @@ func (r *LetterIncomingRepository) Get(ctx context.Context, id uuid.UUID) (*enti
 	return &e, nil
 }
 
+func (r *LetterIncomingRepository) GetByReferenceNumber(ctx context.Context, refNumber *string) (*entities.LetterIncoming, error) {
+	db := DBFromContext(ctx, r.db)
+	var e entities.LetterIncoming
+	if err := db.WithContext(ctx).
+		Where("reference_number = ? AND deleted_at IS NULL", refNumber).
+		First(&e).Error; err != nil {
+		return nil, err
+	}
+	return &e, nil
+}
+
 func (r *LetterIncomingRepository) GetByID(ctx context.Context, id uuid.UUID) (*entities.LetterIncoming, error) {
 	return r.Get(ctx, id)
 }