VB.NET: How to DELETE record on SQL Database

This topic is part of VB.NET SQL Database Basics Tutorial series. On this article, you will learn how to incorporate SQL DELETE statements on your VB.NET application. An SQL DELETE statement removes one or more records from a table. A subset may be defined for deletion using a condition, otherwise all records are removed. For this article, we will focus particularly on updating records in Microsoft SQL Server.



Note: I assumed that you already installed your SQL Server and Visual Studio .NET.

Here is the step-by-step procedure to UPDATE record on SQL server:
1. Create your VB.NET project.
2. Include the following namespaces.

Imports System.Data
Imports System.Data.SqlClient

The System.Data namespace provides access to classes that represent the ADO.NET architecture while the System.Data.SqlClient namespace is the.NET Framework Data Provider for SQL Server.

3. Declare and instantiate your SQLConnection object and Command object as shown below

Dim con As New SqlConnection
Dim cmd As New SqlCommand

4. Pass the SQL connection string to ConnectionString property of your SqlConnection object.

con.ConnectionString = "Data Source=atisource;Initial 
Catalog=BillingSys;Persist Security Info=True;User ID=sa;Password=12345678"

5. Invoke the Open Method to connect to SQL Server.

con.Open()

6. Set the connection of the command object.

cmd.Connection = con

7. Pass the DELETE SQL statement to the command object commandtext as shown below

cmd.CommandText = "DELETE FROM table_name [WHERE condition]"
'For Example:
'DELETE FROM customer WHERE firstname='Fryan0911'

8. Use the ExecuteNonQuery() method to run the DELETE SQL statement.

cmd.ExecuteNonQuery()

The full sample source code of deleting records on SQL Database:

Dim con As New SqlConnection
Dim cmd As New SqlCommand
Try
con.ConnectionString = "Data Source=atisource;Initial Catalog=BillingSys;Persist Security Info=True;User ID=sa;Password=12345678"
con.Open()
cmd.Connection = con
cmd.CommandText = "DELETE FROM table_name WHERE field1='Test'"
cmd.ExecuteNonQuery()

Catch ex As Exception
MessageBox.Show("Error while deleting record on table..." & ex.Message, "Delete Records")
Finally
con.Close()
End Try

Related Topic: VB.NET Tutorial: SQL Database Basics