Updated the category creation to include optional subcategories. First iteration of working with Go's SQL transaction setup.

category.go

@@ -1,5 +1,10 @@
 package main
 
+import (
+	"context"
+	"fmt"
+)
+
 type Category struct {
 	ID            int64         `json:"id"`
 	Name          string        `json:"name"`
@@ -46,20 +51,66 @@ func getAllCategories() (categories []Category, ok bool) {
 	return categories, true
 }
 
-func insertNewCategory(name string) (recordID int32, ok bool) {
+func insertNewCategory(name string, subcategories []Subcategory) (recordID int64, ok bool) {
 	db := getSQLConnection()
 
 	defer db.Close()
 
-	err := db.QueryRow("INSERT INTO category (category_name) VALUES ($1) RETURNING category_id;", name).Scan(&recordID)
+	context := context.Background()
+	transaction, err := db.BeginTx(context, nil)
 
 	if err != nil {
-		//TODO: log this error
 		println(err.Error())
 		return 0, false
-		//panic(err)
 	}
 
+	{
+		statement, err := transaction.Prepare("INSERT INTO category (category_name) VALUES ($1) RETURNING category_id;")
+
+		if err != nil {
+			println(err.Error())
+			return 0, false
+		}
+
+		defer statement.Close()
+
+		statement.QueryRow(name).Scan(&recordID)
+
+		if recordID == 0 {
+			transaction.Rollback()
+			println("Failed to get the last record ID")
+			return 0, false
+		}
+	}
+
+	if len(subcategories) == 0 {
+		return recordID, true
+	}
+
+	{
+		statement, err := transaction.Prepare("INSERT INTO subcategory(subcategory_name, category_id) VALUES($1, $2);")
+
+		if err != nil {
+			println(err.Error())
+			return 0, false
+		}
+
+		defer statement.Close()
+
+		for _, subcategory := range subcategories {
+			println(fmt.Sprintf("For cat %d, add sub '%s'.", recordID, subcategory.Name))
+			_, err := statement.Exec(subcategory.Name, recordID)
+
+			if err != nil {
+				transaction.Rollback()
+				println(err.Error())
+				return 0, false
+			}
+		}
+	}
+
+	transaction.Commit()
+
 	return recordID, true
 }
 

main.go

@@ -164,7 +164,7 @@ func insertCategoryHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	id, ok := insertNewCategory(category.Name)
+	id, ok := insertNewCategory(category.Name, category.Subcategories)
 
 	if !ok {
 		w.WriteHeader(http.StatusInternalServerError)