Handle circular required keys

Use a dummy-value at first and update it later.
Deferrable doesn't seem to work for NOT NULL - only
for FOREIGN KEYs.

postgres/budgets.sql.go

@@ -12,13 +12,18 @@ import (
 
 const createBudget = `-- name: CreateBudget :one
 INSERT INTO budgets
-(name, last_modification)
-VALUES ($1, NOW())
+(name, income_category_id, last_modification)
+VALUES ($1, $2, NOW())
 RETURNING id, name, last_modification, income_category_id
 `
 
-func (q *Queries) CreateBudget(ctx context.Context, name string) (Budget, error) {
-	row := q.db.QueryRowContext(ctx, createBudget, name)
+type CreateBudgetParams struct {
+	Name             string
+	IncomeCategoryID uuid.UUID
+}
+
+func (q *Queries) CreateBudget(ctx context.Context, arg CreateBudgetParams) (Budget, error) {
+	row := q.db.QueryRowContext(ctx, createBudget, arg.Name, arg.IncomeCategoryID)
 	var i Budget
 	err := row.Scan(
 		&i.ID,

postgres/budgetservice.go

@@ -3,6 +3,7 @@ package postgres
 import (
 	"context"
 	"database/sql"
+	"fmt"
 
 	"github.com/google/uuid"
 )
@@ -11,15 +12,18 @@ import (
 func (s *Database) NewBudget(context context.Context, name string, userID uuid.UUID) (*Budget, error) {
 	tx, err := s.BeginTx(context, &sql.TxOptions{})
 	q := s.WithTx(tx)
-	budget, err := q.CreateBudget(context, name)
+	budget, err := q.CreateBudget(context, CreateBudgetParams{
+		Name:             name,
+		IncomeCategoryID: uuid.New(),
+	})
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("create budget: %w", err)
 	}
 
 	ub := LinkBudgetToUserParams{UserID: userID, BudgetID: budget.ID}
 	_, err = q.LinkBudgetToUser(context, ub)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("link budget to user: %w", err)
 	}
 
 	group, err := q.CreateCategoryGroup(context, CreateCategoryGroupParams{
@@ -27,18 +31,25 @@ func (s *Database) NewBudget(context context.Context, name string, userID uuid.U
 		BudgetID: budget.ID,
 	})
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("create inflow category_group: %w", err)
 	}
 
 	cat, err := q.CreateCategory(context, CreateCategoryParams{
-		Name:            "Ready to assign",
+		Name:            "Ready to Assign",
 		CategoryGroupID: group.ID,
 	})
+	if err != nil {
+		return nil, fmt.Errorf("create ready to assign category: %w", err)
+	}
 
-	q.SetInflowCategory(context, SetInflowCategoryParams{
+	err = q.SetInflowCategory(context, SetInflowCategoryParams{
 		IncomeCategoryID: cat.ID,
 		ID:               budget.ID,
 	})
+	if err != nil {
+		return nil, fmt.Errorf("set inflow category: %w", err)
+	}
+
 	tx.Commit()
 
 	return &budget, nil

postgres/queries/budgets.sql

@@ -1,7 +1,7 @@
 -- name: CreateBudget :one
 INSERT INTO budgets
-(name, last_modification)
-VALUES ($1, NOW())
+(name, income_category_id, last_modification)
+VALUES ($1, $2, NOW())
 RETURNING *;
 
 -- name: SetInflowCategory :exec

postgres/schema/0008_categories.sql

@@ -4,7 +4,8 @@ CREATE TABLE categories (
     category_group_id uuid NOT NULL REFERENCES category_groups (id) ON DELETE CASCADE,
     name varchar(50) NOT NULL
 );
-ALTER TABLE budgets ADD COLUMN income_category_id uuid NOT NULL REFERENCES categories (id) DEFERRABLE;
+ALTER TABLE budgets ADD COLUMN
+    income_category_id uuid NOT NULL REFERENCES categories (id) DEFERRABLE INITIALLY DEFERRED;
 
 -- +goose Down
 ALTER TABLE budgets DROP COLUMN income_category_id;