删除feature的几种方法，性能

1、IFeatureCursor 游标查询后，遍历删除

2、更新游标删除IFeatureCursor.DeleteFeature()

3、ITable.DeleteSearchedRows删除

4、 IDataset.Workspace.ExecuteSQL

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。