Question

I want to change the app.setting connection string at the run time. I have some code to change it but i can’t do this. there is no error appear during the run time. But there is no change during execution.

This is my partial code :

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <configSections>
    </configSections>
    <connectionStrings>
        <add name="Punch_Uploader.Properties.Settings.testConnectionString"
            connectionString="server=localhost;User Id=root;password=test123;database=test"
            providerName="MySql.Data.MySqlClient" />
        <add name="Punch_Uploader.Properties.Settings.testConnectionString1"
            connectionString="server=172.23.2.52;User Id=root;password=test123;database=test"
            providerName="MySql.Data.MySqlClient" />
    </connectionStrings>
</configuration>

And:

Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.ConnectionStrings.ConnectionStrings.Add(
    new ConnectionStringSettings("Punch_Uploader.Properties.Settings.testConnectionString2", 
        String.Format(
            "server={0};Port={1}; database={2};User Id={3};password={4};providerName={5}", 
            "172.23.2.32", "3306", "test", "root", "test123", "MySql.Data.MySqlClient")
        )
);
config.Save(ConfigurationSaveMode.Modified, true);
ConfigurationManager.RefreshSection("connectionStrings"); 

MessageBox.Show(ConfigurationManager
    .ConnectionStrings["Punch_Uploader.Properties.Settings.testConnectionString2"]
    .ConnectionString);

The above code is not working for me….

Please help me to fix this.

Answer 1

ConnectionStringSettings settings =
    ConfigurationManager.ConnectionStrings["Punch_Uploader.Properties.Settings.testConnectionString"];

string connectString = settings.ConnectionString;    

SqlConnectionStringBuilder builder =
        new SqlConnectionStringBuilder(connectString);

builder.DataSource = "172.23.2.52:3306";
builder.InitialCatalog = "test";
builder.UserID = "root";
builder.Password = "test123";

As mentioned in the comment to the previous answered I can confirm this method works as I’ve used it before to switch between different database environments.