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

postgres/queries/budgets.sql

@@ -4,6 +4,11 @@ INSERT INTO budgets
 VALUES ($1, NOW())
 RETURNING *;
 
+-- name: SetInflowCategory :exec
+UPDATE budgets
+        SET income_category_id = $1
+        WHERE budgets.id = $2;
+
 -- name: GetBudgetsForUser :many
 SELECT budgets.* FROM budgets 
 LEFT JOIN user_budgets ON budgets.id = user_budgets.budget_id