SqlCommand 和 ExecuteReader 返回非公共成员

Question

I execute a scripted query from a .sql file with SqlCommand.

I get the result with an ExecuteReader.

But values are as non-public member and I can't access it.

Any idea why and how resolve that?

Code

string root = AppDomain.CurrentDomain.BaseDirectory;
string script = File.ReadAllText(root + @"..\SGBD\select_user_from_all_bases.sql");
string connectionString = @"Data Source=(local);Integrated Security=SSPI";
var conn = new SqlConnection(connectionString);

conn.Open();

var users = new SqlCommand(script, conn).ExecuteReader();

foreach (var user in users)
{

}

conn.Close();

Answer 1

This because ExecuteReader() returns a SqlDataReader, not the entries.

Look at the documentation of the SqlDataReader to see how you should do :

private static void ReadOrderData(string connectionString)
{
    string queryString =
        "SELECT OrderID, CustomerID FROM dbo.Orders;";

    using (SqlConnection connection =
               new SqlConnection(connectionString))
    {
        SqlCommand command =
            new SqlCommand(queryString, connection);
        connection.Open();

        SqlDataReader reader = command.ExecuteReader();

        // Call Read before accessing data.
        while (reader.Read())
        {
            Console.WriteLine(String.Format("{0}, {1}", reader[0], reader[1]));
        }

        // Call Close when done reading.
        reader.Close();
    }
}

Answer 2

As mentioned already, you probably shouldn't be using foreach . For compatibility reasons, it needs to be implemented, but a while (reader.Read()) loop is simpler here. That said, you can use foreach anyway if you want. The user values implement IDataRecord , and you can use that interface to access the values.

foreach (IDataRecord user in reader)
{
    // access user[0], user["field"], etc. here
}