c# - 检查有效的 ADO.NET / OLEDB 连接

Question

在大家的大力帮助下，我管理了以下仅适用于 ADO.NET 连接的代码。但是，当我更改与 OLEDB 的连接时，这似乎失败了。我不确定它为什么会发生，但想在您的帮助下解决这个问题。

此代码的目的是检查 ADO.NET 或 OLEDB 连接是否存在。如果它们都不存在，则会引发错误。如果其中任何一个存在，则使用该连接类型将变量值插入到表中。

欢迎任何建议，改进！

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using Microsoft.SqlServer.Dts.Runtime;
using System.Data.OleDb;
using System.Data.Common;

namespace AOC.SqlServer.Dts.Tasks

{

[DtsTask(
    DisplayName = "Custom Logging Task",
    Description = "Writes logging info into a table")]
public class CustomLoggingTask : Task
{

    private string _packageName;
    private string _taskName;
    private string _errorCode;
    private string _errorDescription;
    private string _machineName;
    private double _packageDuration;

    private string _connectionName;
    private string _eventType;
    private string _executionid;
    private DateTime _handlerdatetime;
    public string ConnectionName
    {
        set
        {
            _connectionName = value;
        }
        get
        {
            return _connectionName;
        }
    }


    public string Event
    {
        set
        {
            _eventType = value;
        }
        get
        {
            return _eventType;
        }
    }


    public override DTSExecResult Validate(Connections connections, VariableDispenser variableDispenser, IDTSComponentEvents componentEvents, IDTSLogging log)
    {
        const string METHOD_NAME = "CustomLoggingTask-Validate";

        try
        {

            if (string.IsNullOrEmpty(_eventType))
            {
                componentEvents.FireError(0, METHOD_NAME, "The event property must be specified", "", -1);
                return DTSExecResult.Failure;
            }


            if (string.IsNullOrEmpty(_connectionName))
            {
                componentEvents.FireError(0, METHOD_NAME, "No connection has been specified", "", -1);
                return DTSExecResult.Failure;
            }

            DbConnection connection = connections[_connectionName].AcquireConnection(null) as DbConnection;
            if (connection == null)
            {
                componentEvents.FireError(0, METHOD_NAME, "The connection is not a valid ADO.NET connection", "", -1);
                return DTSExecResult.Failure;
            }

            if (!variableDispenser.Contains("System::SourceID"))
            {
                componentEvents.FireError(0, METHOD_NAME, "No System::SourceID variable available. This task can only be used in an Event Handler", "", -1);
                return DTSExecResult.Failure;
            }

            return DTSExecResult.Success;
        }
        catch (Exception exc)
        {
            componentEvents.FireError(0, METHOD_NAME, "Validation Failed: " + exc.ToString(), "", -1);
            return DTSExecResult.Failure;
        }
    }


    public override DTSExecResult Execute(Connections connections, VariableDispenser variableDispenser, IDTSComponentEvents componentEvents, IDTSLogging log, object transaction)
    {
        try
        {
            string commandText =
@"INSERT INTO SSISLog (EventType, PackageName, TaskName, EventCode, EventDescription, PackageDuration, Host, ExecutionID, EventHandlerDateTime)
VALUES (@EventType, @PackageName, @TaskName, @EventCode, @EventDescription, @PackageDuration, @Host, @Executionid, @handlerdatetime)";

            ReadVariables(variableDispenser);
            DbConnection connection = connections[_connectionName].AcquireConnection(transaction) as DbConnection;
            //SqlConnection connection = (SqlConnection)connections[_connectionName].AcquireConnection(transaction);
            DbCommand command = null;
            //using (SqlCommand command = new SqlCommand())
            if (connection is SqlConnection)
                command = new SqlCommand();
            else if (connection is OleDbConnection)
                command = new OleDbCommand();

            {
                command.CommandText = commandText;
                command.CommandType = CommandType.Text;
                command.Connection = connection;

                command.Parameters.Add(new SqlParameter("@EventType", _eventType));
                command.Parameters.Add(new SqlParameter("@PackageName", _packageName));
                command.Parameters.Add(new SqlParameter("@TaskName", _taskName));
                command.Parameters.Add(new SqlParameter("@EventCode", _errorCode ?? string.Empty));
                command.Parameters.Add(new SqlParameter("@EventDescription", _errorDescription ?? string.Empty));
                command.Parameters.Add(new SqlParameter("@PackageDuration", _packageDuration));
                command.Parameters.Add(new SqlParameter("@Host", _machineName));
                command.Parameters.Add(new SqlParameter("@ExecutionID", _executionid));
                command.Parameters.Add(new SqlParameter("@handlerdatetime", _handlerdatetime));
                command.ExecuteNonQuery();
            }

            return DTSExecResult.Success;
        }
        catch (Exception exc)
        {
            componentEvents.FireError(0, "CustomLoggingTask-Execute", "Task Errored: " + exc.ToString(), "", -1);
            return DTSExecResult.Failure;
        }
    }


    private void ReadVariables(VariableDispenser variableDispenser)
    {
        variableDispenser.LockForRead("System::StartTime");
        variableDispenser.LockForRead("System::PackageName");
        variableDispenser.LockForRead("System::SourceName");
        variableDispenser.LockForRead("System::MachineName");
        variableDispenser.LockForRead("System::ExecutionInstanceGUID");
        variableDispenser.LockForRead("System::EventHandlerStartTime");
        bool includesError = variableDispenser.Contains("System::ErrorCode");
        if (includesError)
        {
            variableDispenser.LockForRead("System::ErrorCode");
            variableDispenser.LockForRead("System::ErrorDescription");
        }

        Variables vars = null;
        variableDispenser.GetVariables(ref vars);

        DateTime startTime = (DateTime)vars["System::StartTime"].Value;
        _packageDuration = DateTime.Now.Subtract(startTime).TotalSeconds;
        _packageName = vars["System::PackageName"].Value.ToString();
        _taskName = vars["System::SourceName"].Value.ToString();
        _machineName = vars["System::MachineName"].Value.ToString();
        _executionid = vars["System::ExecutionInstanceGUID"].Value.ToString();
        _handlerdatetime = (DateTime)vars["System::EventHandlerStartTime"].Value;
        if (includesError)
        {
            _errorCode = vars["System::ErrorCode"].Value.ToString();
            _errorDescription = vars["System::ErrorDescription"].Value.ToString();
        }

        // release the variable locks.
        vars.Unlock();

        // reset the dispenser
        variableDispenser.Reset();
    }
}