无法从C#中获取FoxPro SQL语句以正确执行

我希望这里有人能帮我解决C#和FoxPro database的问题。

以下是从FoxPro（SQL server）数据库中读取的完整方法
我遇到的问题在语句SqlDataReader FP_Reader = FoxProSQLCmd.ExecuteReader();
中当我遍历代码并点击这一行时，它总是跳到catch例程。我假设它是SQL语句中未格式化或无效的内容。Visual Studio不会向我提供除此消息以外的任何错误

"System.InvalidOperationException"类型的首次机会异常发生在System.Data.dll".中

此消息显示在"调试"输出窗口中。

此外，在SQL语句字符串FoxProSQLCommand = "SELECT dfree FROM dbo.gph_description_master WHERE dfree = 'CALIFORNIA BRANDS'";
中我无法使用SELECT *语句，因为我没有访问数据库中所有字段的权限。

下面的SQL语句从SQL Server management studio 中正确运行和执行

SELECT TOP 100000 [dfree]
      FROM [INTRANET].[dbo].[gph_description_master]
      WHERE dfree = 'California brands'

代码为：

private string GetFilenameFromFoxPro(string TemplateNum)
    {
        string TemplateFileNameInFoxPro = TemplateNum.Substring(8); 
        // string FoxProCommand = "SELECT dfree FROM dbo.gph_description_master WHERE tempno='" +                   TemplateFileNameInFoxPro + "'";  // use this command once access has been granted to column 'tempno' in database table.
        string FoxProSQLCommand = "SELECT dfree FROM dbo.gph_description_master WHERE dfree =     'CALIFORNIA BRANDS'";  // This is basically test code at the moment.
        //  string FoxProCommand = "SELECT [dfree] FROM [INTRANET].[dbo.gph_description_master]  WHERE dfree = 'CALIFORNIA BRANDS'";
        string DatabaseCommentField = "";
        SqlConnection FoxProDB = new SqlConnection();

        try 
           {
           FoxProDB.ConnectionString = ("User id=FoxProTemps;" +  
                                        "password=TemplatesRule!;" +          
                                        "Data Source=SQLPROD01;" +        // This is the server
                                        "Initial Catalog=INTRANET;"       // This is the database     
                                        ); 
           FoxProDB.Open();
           MessageBox.Show("FoxPro OPENED!");
           }
        catch
          {
            MessageBox.Show("FoxPro did not open!");
            return("Cannot Connect to TemplatesDatabase");
          }
        try
          {
            SqlCommand FoxProSQLCmd = new SqlCommand(FoxProCommand);              
            SqlDataReader FP_Reader = FoxProSQLCmd.ExecuteReader();  // This is the line that is giving me grief.
            while (FP_Reader.Read())
              {
                DatabaseCommentField = FP_Reader.ToString();
              }
          }
        catch
          {
            MessageBox.Show("SQL Command or SQL Reader did not work!");
            return (TemplateFileNameInFoxPro);
          }
            // ToDo:
            // Add code to parse Database comment fields so Template filename can be extracted
            // TemplateFileNameInFoxPro = DatabaseCommentField          
        FoxProDB.Close();
        return TemplateFileNameInFoxPro;
    }

请分享你的想法、建议或批评
我已尽力提供尽可能多的信息。

谢谢，MTH