connection string problem in winforms

venkata kumar

hi
can any one help me
how to change connections string at run time
current is working with first connection string. run time i need to change second connetion when first connection not found

4 Replies

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Bryian Tan13y ago
hi,

I'm not sure how your application using the setting and I assumed that you only have two connection in the app.config. If that the case, you can try something like

if (System.Configuration.ConfigurationManager.AppSettings["ConnectionString1"] != null)
        {
            //use ConnectionString1
        }
        else
        {
            //use ConnectionString2
        }
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Rohit Sharma13y ago
Step 1: Add a text File in your Project named 'ServerName' (ie.txt) Step 2: Add a class named DynamicConString and add the following code Public Class DynamicConString Private dUserName As String = "sa" Private dPassword As String = "lock" Private dServer As String 'public SqlConnection Cn() Public Function getConnString() As String Dim objReader As System.IO.StreamReader = Nothing objReader = New System.IO.StreamReader(Application.StartupPath & "\ServerName.txt") dServer = objReader.ReadToEnd() objReader.Close() 'return new System.Data.SqlClient.SqlConnection("Data Source=" + dServer + ";User ID=" + dUserName + ";Password=" + dPassword); dServer = "Server=" & dServer & ";Database=VoucherDB;Integrated Security=false;User Id=" & dUserName & ";Password=" & dPassword Return dServer End Function End Class Step 3: Call the class DynamicConnection String Add the Code in the form which starts first during project load like splash screen or Login Dim server As String = getConString.getConnString Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None) config.AppSettings.Settings.Remove("connection") config.AppSettings.Settings.Add("connection", server) config.Save(ConfigurationSaveMode.Modified) ConfigurationManager.RefreshSection("appSettings")
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venkata kumar13y ago
hi
thanks for reply
but this is finding connections from app.config
first connection not found need to open with second connection
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Dorababu Meka13y ago
foreach(ConnectionStringSettings con in ConfigurationManager.ConnectionStrings)
{
string name = con.Name;
string connString = con.ConnectionString;
string provider = con.ProviderName;
}

Select the required as per your code
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