如何在ASP.NET中连接到SQL Server Compact 4.0？

Question

I want connect to SQL Server Compact 4.0 in my ASP.NET application.

Here is example of code:

protected void Page_Load(object sender, EventArgs e)
{
    string connStr = "Data Source=D:\\MyDB.sdf;";
    string sqlStr = "select * from tblMyTable";

    var sqlDataSrc = new SqlDataSource(connStr, sqlStr);

    GridWithUrls.DataSource = sqlDataSrc;
    GridWithUrls.DataBind();
}

But I have the next error: "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. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)"

The SqlDataSource has constructor with three parameters, one of them is 'providerName' so, how to specify that I want definitely use Sql Server Compact provider ? Also I have added System.Data.SqlServerCe reference..

Answer 1

尝试：

providerName = "System.Data.SqlServerCe.4.0"

Answer 2

Place the single database file (eg MySite.sdf ) in the App_Data folder.

Add a connectionStrings entry to web.config to allow connection to the database:

web.config :

<configuration>
   <connectionStrings>
      <add name="db" 
           connectionString="Data Source=|DataDirectory|\MySite.sdf"
           providerName="System.Data.SqlServerCe.4.0" />
   </connectionStrings>
   ...
</configuration> 

And then you can create a connection as desired through the connection string name db :

public static DbConnection CreateConnection()
{
   //Get connection string named "db"
   String csName = "db";
   ConnectionStringSettings cs = ConfigurationManager.ConnectionStrings[csName];
   if (cs == null)
      throw new ConfigurationErrorsException("Could not find connection string \"" + csName + "\"");

   //Get a factory based on the "ProviderName" in the connection string
   DbProviderFactory factory = DbProviderFactories.GetFactory(cs.ProviderName);
   if (factory == null)
      throw new Exception("Unable to locate factory for " + cs.ProviderName);

   //Have the factory create us a connection object
   DbConnection conn = factory.CreateConnection();

   //Open the connection with the connection string from web.config
   conn.ConnectionString = cs.ConnectionString;
   conn.Open();

   //Give the ready connection to the user
   return conn;
}

Note : Any code is released into the public domain. No attribution required.

Answer 3

Have a look at the example here:

http://connectionstrings.com/sql-server-2005-ce

If you want to specify the location explicitly try:

Data Source=" + (System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase) + "\\MyDB.sdf;Persist Security Info=False;

Answer 4

You could pull the data into a datatable first:

        using (SqlCeConnection c = new SqlCeConnection(
            Properties.Settings.Default.DataConnectionString))
        {
            c.Open();

            // Create new DataAdapter
            using (SqlCeDataAdapter a = new SqlCeDataAdapter(
                "SELECT * FROM tblMyTable", c))
            {

                // Use DataAdapter to fill DataTable
                DataTable t = new DataTable();
                a.Fill(t);

                // Render data onto the screen
                dataGridView1.DataSource = t;
            }
        }