Saving a transaction must be atomic. If updating inventory stock fails mid-process, the entire invoice sequence must roll back immediately via an explicit SqlTransaction .
Replace the code in your Form1.vb file with the complete production implementation below: vbnet+billing+software+source+code
or external libraries to generate a physical or PDF receipt. 2. Core Source Code Snippet Saving a transaction must be atomic
| Module | Purpose | Typical Code Elements | |---|---|---| | | Add, edit, delete, and view products. | DataGridView for listing products, TextBoxes for product details (name, price, stock), Buttons for CRUD operations (Create, Read, Update, Delete), ADO.NET code to interact with the database (e.g., SQL INSERT, UPDATE, DELETE statements). | | Billing / POS Module | Create new bills, add items to cart, calculate totals, apply discounts, and process payments. | ListView or DataGridView for the shopping cart, TextBoxes for item code/barcode input, buttons to add items to cart, calculate total, apply tax/discount, and complete the sale. Includes business logic for price calculations and inventory updates. | | Customer Management | Manage customer information, view purchase history, and track balances. | Forms for adding/editing customer details, a DataGridView to list customers, and search functionality. | | Reporting | Generate invoices, sales reports, stock reports, and other business intelligence. | Use of Crystal Reports or built-in .NET reporting tools. Code to fetch data from the database and bind it to the report viewer control. | | Database Connection | Establish and manage the connection between the application and the database. | A module or class containing shared functions for opening and closing database connections. Typical ADO.NET objects include SqlConnection , SqlCommand , SqlDataAdapter , and DataSet (for SQL Server) or OleDbConnection , OleDbCommand , etc. (for MS Access). | | | Billing / POS Module | Create
' Update the grand total UpdateTotal(itemTotal) End If End Sub
: Double-check that all component identifier properties match the naming conventions listed in the UI section (such as dgvInvoiceItems , btnSaveInvoice ).