Connection error

Question

I am creating a Windows Forms application using C# and am having a problem connecting to SQL Server CE 4.0.

The application database is in the folder AppData of the logged-in user. To get the folder path AppData I use the Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) that in my case returns "C:/Users/Richard.days/Appdata/Roaming/".

Inside this folder I have the following structure: Company name/ Application name. This results in the path C:/Users/richard.dias/AppData/Roaming/Nome da empresa/Nome do aplicativo/.

In the application folder the database is inside the folder App_Data.

To make the connection I am passing the absolute path to the file .SDF database and password for connection.

Final result of connection string: Data Source=C:/Users/richard.dias/AppData/Roaming/Nome da empresa/Nome do aplicativo/App_Data/bd.sdf;Password=123456;

Code for connection opening:

using (var conexao = new SqlConnection(STR_CON))
using (var comando = new SqlCommand())
{
    comando.CommandText = sql;
    comando.Parameters.AddWithValue("@p1", p1);
    comando.Parameters.AddWithValue("@p2", p2);
    comando.Parameters.AddWithValue("@p3", p3);

    conexao.Open();

    comando.Connection = conexao;
    obteveSucesso = comando.ExecuteNonQuery() == 3;

    conexao.Close();
}

Upon entering open connection the following error occurs:

Instance-specific or network error when connecting to SQL Server. The server was not found or not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (Preview: Named Pipes Provider, error: 40 - Unable to open connection to SQL Server)

or in English:

A network-Related or instance-specific error occurred while establishing a Connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote Connections. (Preview: Named Pipes Provider, error: 40 - Could not open a Connection to SQL Server)

Answer 1

You must use SqlCeConnection, SqlCeCommand and similar instead of SqlConnection. Add a reference to System.Data.SqlServerCe.dll.

_[Original]

You must use SqlCeConnection, SqlCeCommand etc Instead of SqlConnection. Add a Reference to System.Data.SqlServerCe.dll.