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SqlConnection Constructor (String)

Initializes a new instance of the SqlConnection class when given a string that contains the connection string.

Namespace:  System.Data.SqlClient
Assembly:  System.Data (in System.Data.dll)

Public Sub New ( _
	connectionString As String _


Type: System.String
The connection used to open the SQL Server database.

When a new instance of SqlConnection is created, the read/write properties are set to the following initial values unless they are specifically set using their associated keywords in the ConnectionString property.


Initial value






empty string ("")


empty string ("")

You can change the value for these properties only by using the ConnectionString property. The SqlConnection class provides functionality for creating and managing the contents of connection strings.

The following example creates and opens a SqlConnection.

Private Sub OpenSqlConnection()
    Dim connectionString As String = GetConnectionString()

    Using connection As New SqlConnection(connectionString)


        Console.WriteLine("State: {0}", connection.State)
        Console.WriteLine("ConnectionString: {0}", _
    End Using
End Sub

Private Function GetConnectionString() As String
    ' To avoid storing the connection string in your code,  
    ' you can retrieve it from a configuration file, using the
    ' System.Configuration.ConfigurationSettings.AppSettings property
    Return "Data Source=(local);Database=AdventureWorks;" _
      & "Integrated Security=SSPI;"
End Function

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.