ArcEngine,C#数据删除几种方法和性能比较

       ArcEngine,C#数据删除几种方法和性能比较

       By Yanleigis  Landgis@126.com

       一、  几种删除方法代码

       1.  查询结果中删除

  private void Delete1(IFeatureClass PFeatureclass)

        {

            IQueryFilter pQueryFilter = new QueryFilterClass();

            pQueryFilter.WhereClause = "objectID<=" + DeleteNum;

            IFeatureCursor pFeatureCursor = PFeatureclass.Search(pQueryFilter, false);            IFeature pFeature = pFeatureCursor.NextFeature();

            while (pFeature != null)

            {

                pFeature.Delete();

                pFeature = pFeatureCursor.NextFeature();

            }

            System.Runtime.InteropServices.Marshal.ReleaseComObject(pQueryFilter);

        }

       2.  更新游标删除

private void Delete2(IFeatureClass PFeatureclass)

        {

            IQueryFilter pQueryFilter = new QueryFilterClass();

            pQueryFilter.WhereClause = "objectID<=" + DeleteNum;

            IFeatureCursor pFeatureCursor = PFeatureclass.Update(pQueryFilter, false);

            IFeature pFeature = pFeatureCursor.NextFeature();

            while (pFeature != null)

            {

                pFeatureCursor.DeleteFeature();

                pFeature = pFeatureCursor.NextFeature();

            }

            System.Runtime.InteropServices.Marshal.ReleaseComObject(pQueryFilter);

        }

       3.  使用DeleteSearchedRows删除

private void Delete4(IFeatureClass PFeatureclass)

        {

            IQueryFilter pQueryFilter = new QueryFilterClass();

            pQueryFilter.WhereClause = "objectID<=" + DeleteNum;

            ITable pTable = PFeatureclass as ITable;

            pTable.DeleteSearchedRows(pQueryFilter);

            System.Runtime.InteropServices.Marshal.ReleaseComObject(pQueryFilter);

        }

       4.  ExecuteSQL删除

private void Delete4(IFeatureClass PFeatureclass)

        {

            IDataset pDataset = PFeatureclass as IDataset;

            pDataset.Workspace.ExecuteSQL("delete from " + PFeatureclass.AliasName + " where objectid<=" + DeleteNum);

        }

       二、  测试性能和比较

       1、       相同的数据条件，删除2000条记录

       2、       测试代码

IFeatureLayer pFeatureLayer = axMapControl1.Map.get_Layer(0) as IFeatureLayer;

            IFeatureClass PFeatureClass = pFeatureLayer.FeatureClass;

            System.Diagnostics.Stopwatch MyWatch = new System.Diagnostics.Stopwatch();

            MyWatch.Start();

            Delete1(PFeatureClass)

            //Delete2(PFeatureClass);

            //Delete3(PFeatureClass);

            //Delete4(PFeatureClass);

            //Delete5(PFeatureClass);

            MyWatch.Stop();

            MessageBox.Show("删除时间:" + MyWatch.ElapsedMilliseconds.ToString() + "毫秒");

       3、       测试情况

       测试方法

       第一次时间（单位ms）

       第一次时间（单位ms）

       1

       5214ms

       5735ms

       2

       299ms

       290Ms

       3

       59ms

       28ms

       4

       26ms

       26ms

       三、  结论

       1、         使用ExecuteSQL删除最快，数据库的效率最高。

       2、         DeleteSearchedRows和ExecuteSQL属于批量删除，性能较优。

       3、         查询结果中删除，速度最慢，如果你使用这种方法，建立你马上修改你的程序，因为你在浪费时间。

       4、       小数据量记录数小于500000条，请使用DeleteSearchedRows或ExecuteSQL，否则使用更新游标删除(方法2)，加上进度条，这样界面很友好。