add get budgets method

internal/services/budget/budget_service.go

@@ -64,3 +64,31 @@ func (s *BudgetService) AddBudget(ctx context.Context, budget *BudgetEntity) (*B
 	}
 	return budget, nil
 }
+
+func (s *BudgetService) GetBudgets(ctx context.Context) ([]*BudgetEntity, error) {
+	userId, err := context_utils.GetUserId(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	query := `SELECT b.id, b.name, b.start_day, b.monthly_limit FROM budgets b JOIN users_budgets ub ON ub.budget_id = b.id WHERE ub.user_id = @user_id`
+	args := pgx.NamedArgs{
+		"user_id": userId,
+	}
+	rows, err := s.db.Query(ctx, query, args)
+	if err != nil {
+		return nil, err
+	}
+	budgets := []*BudgetEntity{}
+	defer rows.Close()
+	for rows.Next() {
+		budget := &BudgetEntity{}
+		err = rows.Scan(&budget.Id, &budget.Name, &budget.StartDay, &budget.MonthlyLimit)
+		if err != nil {
+			return nil, err
+		}
+		budgets = append(budgets, budget)
+	}
+
+	return budgets, nil
+}