如何避免每次更改Windows工作流时重建数据库

我也面临着类似的问题,每当工作流设计发生变化时,数据库中的所有旧工作流实例都会使用抛出错误。

为了克服这个问题,我为每种类型的工作流创建了跟踪配置文件。如果我更改了任何工作流,我将更新配置文件的版本。这对我很有用……这是示例代码-

为此,您需要将跟踪服务添加到工作流运行时。

trackingprofile profile=createprofile();

storeprofiletodb(profile,connstring,typeof(exceptionwf.parametereexceptionwf),“2.0.0.0”);

专用静态跟踪配置文件createprofile() { trackingprofile myprofile=new trackingprofile();

        ActivityTrackingLocation stateActivityLocation = CreateActivityLocation(typeof(StateActivity));
        AddActivityExecutionStatus(stateActivityLocation);

        ActivityTrackingLocation eventDrivenActLoc = CreateActivityLocation(typeof(EventDrivenActivity));
        AddActivityExecutionStatus(eventDrivenActLoc);

        ActivityTrackPoint actPt = new ActivityTrackPoint();

        actPt.MatchingLocations.Add(stateActivityLocation);
        actPt.MatchingLocations.Add(eventDrivenActLoc);
        myProfile.ActivityTrackPoints.Add(actPt);

        WorkflowTrackPoint workflowTrack = CreateWorkflowTrackPoint();
        myProfile.WorkflowTrackPoints.Add(workflowTrack);

        UserTrackPoint utp = new UserTrackPoint();
        UserTrackingLocation ul = new UserTrackingLocation();
        ul.ActivityType = typeof(HandleExternalEventActivity);
        ul.ArgumentType = typeof(object);
        ul.MatchDerivedArgumentTypes = true;
        ul.MatchDerivedActivityTypes = true;
        utp.MatchingLocations.Add(ul);

        myProfile.UserTrackPoints.Add(utp);
        myProfile.Version = new Version("1.0.0.0");
        return myProfile;
    }

    private static void StoreProfileToDB(TrackingProfile profile, string connString, Type wfType,string version)
    {
        TrackingProfileSerializer serializer = new TrackingProfileSerializer();
        System.IO.StringWriter writer = new System.IO.StringWriter(new StringBuilder());
        serializer.Serialize(writer, profile);
        SqlConnection conn = null;
        try
        {
            if (!String.IsNullOrEmpty(connString))
            {
                conn = new SqlConnection(connString);


                string storedProc = "dbo.UpdateTrackingProfile";
                SqlCommand cmd = new SqlCommand(storedProc, conn);
                cmd.CommandType = System.Data.CommandType.StoredProcedure;

                SqlParameter param = new SqlParameter("@TypeFullName", SqlDbType.NVarChar, 128);
                param.Direction = ParameterDirection.Input;
                param.Value = wfType.FullName;
                cmd.Parameters.Add(param);


                param = new SqlParameter("@AssemblyFullName", SqlDbType.NVarChar, 256);
                param.Direction = ParameterDirection.Input;
                param.Value = wfType.Assembly.FullName;
                cmd.Parameters.Add(param);


                param = new SqlParameter("@Version", SqlDbType.VarChar, 32);
                param.Direction = ParameterDirection.Input;
                //Note that you should increment version number for your
                //TrackingProfile to be able to use new TrackingProfile.
                //Default version is "1.0.0.0, It uses the default profile if not increamented.
                param.Value = version;
                cmd.Parameters.Add(param);

                param = new SqlParameter("@TrackingProfileXml", SqlDbType.NText);
                param.Direction = ParameterDirection.Input;
                param.Value = writer.ToString();
                cmd.Parameters.Add(param);

                conn.Open();
                cmd.ExecuteNonQuery();

            }//if
        }// try
        catch (Exception ex)
        {
            if (ex is SqlException)
            {
                //Check to see if it's a version error
                if (ex.Message.Substring(0, 24) == "A version already exists")
                {
                    EventLogger.Log("A profile with the same version already exists in database");
                }//if
                else
                {
                    EventLogger.Log("Error writing profile to database : " + ex.ToString());
                }
            }
            else
            {
                EventLogger.Log("Error writing profile to database : " + ex.ToString());
            }
        }
        finally
        {
            if (conn != null) { conn.Close(); }
        }
    }