SSIS脚本任务，SqlException处理问题

Question

我要做的是在SSIS中创建一个框架，以动态生成制表符分隔的UTF8文本文件。数据源是SQL Server，要输出的查询存储在物理数据库表中，SQL查询和一些其他参数（例如文件输出位置）通过变量传递给SSIS脚本任务。然后执行查询，然后将结果流式传输到指定位置。

这部分工作正常 - 但是当我尝试引入异常处理时，我开始遇到一些问题。如果源SQL中存在错误，我希望抛出异常并将SQL Server错误消息插回到源表中。再次，我使用SqlException类使这个工作。但是，根据SQL错误，可能生成也可能不生成空白的0字节文本文件。例如，源SQL中的语法错误将直接抛出到catch块，但除以0错误会创建一个空白的0字节文本文件。在这两种情况下，源表都会更新错误。我怎么能避免这个？无论错误是什么，我都不希望生成文件。

这就是我拼凑在一起的...我是C＃的菜鸟，这是我第一次尝试C＃编码，所以如果这里有明显的男生错误，或者我有办法改善这一点，我如果你能指出这些，我将不胜感激！

由于

/*
   Microsoft SQL Server Integration Services Script Task
   Write scripts using Microsoft Visual C# 2008.
   The ScriptMain is the entry point class of the script.
*/

using System;
using System.Data;
using Microsoft.SqlServer.Dts.Runtime;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;
using System.Text;
//using System.Data.SqlClient;


namespace ST_5f2e36fd61064ad8ae13e81d97fe899e.csproj
{
    [System.AddIn.AddIn("ScriptMain", Version = "1.0", Publisher = "", Description = "")]
    public partial class ScriptMain : Microsoft.SqlServer.Dts.Tasks.ScriptTask.VSTARTScriptObjectModelBase
    {

        #region VSTA generated code
        enum ScriptResults
        {
            Success = Microsoft.SqlServer.Dts.Runtime.DTSExecResult.Success,
            Failure = Microsoft.SqlServer.Dts.Runtime.DTSExecResult.Failure
        };
        #endregion

        public void Main()
        {
            //establish connection to data source using ADONET connection manager
            SqlConnection myADONETConnection = new SqlConnection();
            myADONETConnection = (SqlConnection)(Dts.Connections["ADONET"].AcquireConnection(Dts.Transaction) as SqlConnection);


            //variable declarations
            int ReportId = (int)Dts.Variables["ReportId"].Value;
            bool ExportColumnNames =(bool) Dts.Variables["ExportColumnNames"].Value;
            string SQLQuery = Dts.Variables["Query"].Value.ToString();
            string strFilePath = "\\\\" + Path.Combine(Path.Combine(Dts.Variables["OutputServerName"].Value.ToString(), Dts.Variables["OutputFilepath"].Value.ToString()), Dts.Variables["OutputFilename"].Value.ToString());
            string strColumnNames = "";

            SqlDataReader reader;


            using (myADONETConnection)
            {
                try
                {
                    using (reader = new SqlCommand(SQLQuery, myADONETConnection).ExecuteReader())
                    {
                        //get the column names from the query into a string variable
                        //or use DataTable instead?  which is better?

                            for (int col = 0; col < reader.FieldCount; col++)
                            {
                                strColumnNames += reader.GetName(col).ToString() + "\t";
                            }
                            // remove final \t from strColumnName string
                            strColumnNames = strColumnNames.Remove(strColumnNames.Length - 1);



                        using (StreamWriter writer = new StreamWriter(strFilePath)) //creates file; also creates 0 byte file on divide by 0 SQL error...
                        {
                            //insert column names (only if flag on table is set to true)
                            if (ExportColumnNames == true)
                            {
                                writer.WriteLine(strColumnNames);
                            }

                            //insert data
                            while (reader.Read())
                            {
                                //if (reader.HasRows)
                                //{

                                StringBuilder sb = new StringBuilder(reader[0].ToString());

                                for (int i = 1; i < reader.FieldCount; i++)
                                {
                                    sb.AppendFormat("\t{0}", reader[i]);
                                } //end for
                                writer.WriteLine(sb.ToString());

                                //} //end if

                            } //end while

                        } //end (using streamwriter)

                        //reader.Close();
                    } //end (using reader) (closes the reader)

                    //update source table as success
                    var command = new SqlCommand("UPDATE tblAnalyticsFrameworkControlTable SET ExportDate = GETDATE(), ExportSuccessful = 1 WHERE ID = @ID", myADONETConnection);

                    SqlParameter ID = new SqlParameter();
                    ID.ParameterName = "@ID";
                    ID.Value = ReportId;
                    command.Parameters.Add(ID);

                    command.ExecuteNonQuery();

                    myADONETConnection.Close();

                } //end try

                catch (SqlException ex)
                {
                    //insert error message back to table
                    var command = new SqlCommand("UPDATE tblAnalyticsFrameworkControlTable SET ExportDate = GETDATE(), ExportSuccessful = 0, ExportErrorMessage = @ErrorMessage WHERE ID = @ID", myADONETConnection);

                    SqlParameter ErrorMessage = new SqlParameter();
                    ErrorMessage.ParameterName = "@ErrorMessage";
                    ErrorMessage.Value = ex.Message;
                    command.Parameters.Add(ErrorMessage);

                    SqlParameter ID = new SqlParameter();
                    ID.ParameterName = "@ID";
                    ID.Value = ReportId;
                    command.Parameters.Add(ID);

                    command.ExecuteNonQuery();

                    //remove blank file created by StreamWriter method (preferably without removing pre-existing valid files if possible!)
                    File.Delete(strFilePath);

                } //end catch

                Dts.TaskResult = (int)ScriptResults.Success;
            }
        }
    }
}