ADO.NET SQL Server Connection in VB.NET | GuruTech
You can connect your VB.Net application to data in a SQL Server database using the Microsoft .NET Framework Data Provider for SQL Server. The first step in a VB.Net application is to create an instance of the Server object and to establish its connection to an instance of SQL Server.
ADO.NET SQL Server Connection
The SqlConnection Object is Handling the part of physical communication between the application and the SQL Server Database. An instance of the SqlConnection class in .NET Framework is supported the Data Provider for SQL Server Database. The SqlConnection instance takes Connection String as argument and pass the value to the Constructor statement. When the connection is established , SQL Commands may be executed, with the help of the Connection Object, to retrieve or manipulate data in the database. Once the Database activities over , Connection should be closed and release the database resources .
Sql Server connection string
connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;
User ID=UserName;Password=Password"
connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;
User ID=UserName;Password=Password"
"Server=localhost\sqlexpress"
The Close() method in SqlConnection class is used to close the Database Connection. The Close method rolls back any pending transactions and releases the Connection from the SQL Server Database.
A Sample VB.Net Program that connect SQL Server using connection string.
Imports System.Data.SqlClient
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim connetionString As String
Dim cnn As SqlConnection
connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password"
cnn = New SqlConnection(connetionString)
Try
cnn.Open()
MsgBox("Connection Open ! ")
cnn.Close()
Catch ex As Exception
MsgBox("Can not open connection ! ")
End Try
End Sub
End Class
Connecting to SQL Server using windows authentication
"Server= localhost; Database= employeedetails;
Integrated Security=SSPI;"
Trusted Connection from a CE device
connetionString="Data Source=ServerName;
Initial Catalog=DatabaseName;Integrated Security=SSPI;
User ID=myDomain\UserName;Password=Password;
This will only work on a CE device
Connect via an IP address
connetionString="Data Source=IP_ADDRESS,PORT;
Network Library=DBMSSOCN; Initial Catalog=DatabaseName;
User ID=UserName;Password=Password"
1433 is the default port for SQL Server.
A sample VB.Net program that demonstrate how to execute sql statement and read data from SQL server.
Imports System.Data.SqlClient
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim connetionString As String
Dim connection As SqlConnection
Dim command As SqlCommand
Dim sql As String
connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password"
sql = "Your SQL Statement Here , like Select * from product"
connection = New SqlConnection(connetionString)
Try
connection.Open()
command = New SqlCommand(sql, connection)
Dim sqlReader As SqlDataReader = command.ExecuteReader()
While sqlReader.Read()
MsgBox(sqlReader.Item(0) & " - " & sqlReader.Item(1) & " - " & sqlReader.Item(2))
End While
sqlReader.Close()
command.Dispose()
connection.Close()
Catch ex As Exception
MsgBox("Can not open connection ! ")
End Try
End Sub
End Class