Implement new budget with transaction to be able to satisfy not null columns

postgres/budgetservice.go

@@ -22,5 +22,24 @@ func (s *Database) NewBudget(context context.Context, name string, userID uuid.U
 		return nil, err
 	}
 
+	group, err := q.CreateCategoryGroup(context, CreateCategoryGroupParams{
+		Name:     "Inflow",
+		BudgetID: budget.ID,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	cat, err := q.CreateCategory(context, CreateCategoryParams{
+		Name:            "Ready to assign",
+		CategoryGroupID: group.ID,
+	})
+
+	q.SetInflowCategory(context, SetInflowCategoryParams{
+		IncomeCategoryID: cat.ID,
+		ID:               budget.ID,
+	})
+	tx.Commit()
+
 	return &budget, nil
 }