Database Connectivity

Question

How to connect to various databases with vb.net code.

Satyapriya Nayak · Answer

Hi Anil Procedure to connect to 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 as shown below Dim con As New SqlConnection SQLConnection class represents an open connection to a SQL Server database. 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 The connectionstring value usually contains the following : Data Source - physical server hostname Initial Catalog - your database name User ID - SQL username use to connect to the server Password - SQL username's password On this sample I am using an SQL Server 2005. For the connectionstring for other SQL version you can get it from here http://www.connectionstrings.com/. 5. Last step is to invoke the Open method of the connection object con.Open() The complete sample sourcecode: Imports System.Data.SqlClient Imports System.Data Private Sub ConnectToSQL() Dim con As New SqlConnection Dim cmd As New SqlCommand con.ConnectionString = Data Source=atisource;Initial Catalog=BillingSys;Persist Security Info=True;User ID=sa;Password=12345678 con.Open() End Sub To capture if the connection was successful or not just tweak the above code: Imports System.Data.SqlClient Imports System.Data Private Sub ConnectToSQL() 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() Catch ex As Exception MessageBox.Show(Error while connecting to SQL Server. & ex.Message) Finally con.Close() 'Whether there is error or not. Close the connection. End Try End Sub Thanks