我已经使一个自定义类继承IDataReader并且已经成功
实现了一个使用C#对象而不是DataTable的自定义类的自定义ServerWriter sqlBulkCopy.
实现了一个使用C#对象而不是DataTable的自定义类的自定义ServerWriter sqlBulkCopy.
这被证明是一个更有效的方法,我怀疑.
现在我想读,我有一些问题
这是IDataReader:
// get Server Data Table Object IDataReader public class GetSDTOIDataReaderM : IDataReader { //private IEnumerator<MyTestObject> enumerator = null; public MysqLDbTableObject.Raw.sqlDbTableM propsqlTbl { get; set; } // implementing relevant GetValue(),filedCount() and Read() // this is how I did with WriteToServer public bool Read() { return ++this.ReaderRowsCount < this.propsqlTbl.Table.ElementAt(0).Row.Count; } }
该对象与其相应的sqlTable精确映射.
在我的自定义IDataReader中设置一个sqlCommand到ExecuteReader()没有工作,所以我试过
IDbCommand然后它编译,但仍然在尝试阅读
我收到一个错误:
Unable to cast object of type ‘System.Data.sqlClient.sqlDataReader’ to
type ‘GetSDTOIDataReaderM’
this.propComunicator.AsGetSDTOCom().sqlCmd.Connection.Open(); //this is the line of the error using (this.propComunicator.AsGetSDTOCom().SDTOIDataReader = (Raw.Comunicator.Raw.GetSDTOIDataReaderM)this.propComunicator.AsGetSDTOCom().sqlCmd.ExecuteReader()) { }
写入服务器它的工作,我怎么能正确实现与读?
UPDATE
更多关于我的模块
public class TransManSF { public enum CommunicatorTypeS { Reader,Adapter,GetSDTOReaderA,sqlBcpyIDataReaderM }; public enum DbIntreactorTypeS { TableObject,TableRowObject,Sproc,sqlCmd }; public enum sqlCmdActionS { NotSet,SELECT,INSERT,UPDATE,DROP }; public enum sqlCmdStrSelModeS { Single,RecentEfected,count,All,Top10,Top100,Top1000 }; public enum sqlCmdStrSelOrderByS { NotSet = 0,Asc = 1,Desc = 2 }; public enum sqlCmdStrSetterModeS { Single,Multi}; public enum STDOTypeS { NotSet,ServerWriter,ServerTableGetter,ServerBiDerctional } public enum SprocTypeS { Sproc,TvPSrpoc } public enum TransExecActionTypeS { WriteToServer,GetTable } } public static TransMan.Raw.ComunicatorCLF.BulkCopyComSCL AsBulkCopyCom(this TransMan.Raw.ComunicatorCLF.ComunicatorM SelfCom) { return (TransMan.Raw.ComunicatorCLF.BulkCopyComSCL)SelfCom; } virtual public void ExecuteTransaction(AppMods.DataBase.TransManSF.TransExecActionTypeS parSelectedTransType,TransManSF.sqlCmdStrSelOrderByS parExecOrderByS,int OrderByOrdinal = 0) { if (parSelectedTransType == AppMods.DataBase.TransManSF.TransExecActionTypeS.WriteToServer) using (this.propComunicator.AsBulkCopyCom().Conn) { this.propComunicator.AsBulkCopyCom().Conn.Open(); using (var IDRdrServerWriter = this.propComunicator.AsBulkCopyCom().ServerWriter) { var Eng = this.propExecuter.AsBulkCopyExec().Engine; Eng.BulkCopyTimeout = 240; Eng.WriteToServer(IDRdrServerWriter); } this.propComunicator.AsBulkCopyCom().Conn.Close(); } else if (parSelectedTransType == AppMods.DataBase.TransManSF.TransExecActionTypeS.GetTable) { var DreaderCom = this.propComunicator.AsDReaderCom(); using (DreaderCom.sqlCmd.Connection) { DreaderCom.sqlCmd.Connection.Open(); using (DreaderCom.Driver = DreaderCom.sqlCmd.ExecuteReader()) { if (DreaderCom.Driver.HasRows) while (DreaderCom.Driver.Read()) { for (int i = 0; i < DreaderCom.Driver.FieldCount; i++) { var CurRdrColumn = DreaderCom.Driver.GetValue(i); this.Table[i,0] = CurRdrColumn; } } } DreaderCom.sqlCmd.Connection.Close(); } } } public struct customComConfgBulkCopyA { public TransManSF.CommunicatorTypeS ComType; public customComConfgBulkCopyA(TransManSF.CommunicatorTypeS ctrComType = TransManSF.CommunicatorTypeS.sqlBcpyIDataReaderM) { this.ComType = ctrComType; } } public sealed class BulkCopyComSCL :CustomComA { public new Configurations.comunicator.customComConfgBulkCopyA Meta; public sqlConnection Conn { get; set; } public Raw.sqlBcpyIDataReaderM ServerWriter { get; set; } } public class sqlDbTableM : sqlDB1stTransA { virtual public DbSchema.Raw.TableDictionaryA TableDict { get; set; } public virtual new TransMan.Raw.Configurations.SDB1stTransConfgF.SDTOMetaA Meta { get; set; } virtual public Raw.ColumnSetsCollM Table { get; set; } public override TransMan.Raw.ComunicatorCLF.ComunicatorM propComunicator { get { return base.propComunicator; } set { base.propComunicator = value; } } public override TransMan.Raw.Executers.ExecuterM propExecuter { get { return base.propExecuter; } set { base.propExecuter = value; } } public sqlDbTableM(TransManSF.STDOTypeS ctrTransType) : base(TransManSF.DbIntreactorTypeS.TableObject) { } } public sealed class GetSDTOComSCL : CustomComA { public new Configurations.comunicator.customComConfgGetSDTOReaderA Meta; public new IDbCommand sqlCmd; public Raw.GetSDTOIDataReaderM SDTOIDataReader { get; set; } }
解决方法
简短的答案:您不能更改sqlCommand.ExecuteReader()返回的类型.
它将始终是sqlDataReader的一个实例.
各种解决方案
1把你所了解的东西包裹起来.
如果你去极端,写自己的IDbProviderFactory,它包装一个sqlConnection与自己的连接,命令和datareader类.
例如,这就是Miniprofiler对所有sql请求进行测试,并收集执行时间,行数等
或者您可以使用某种扩展方法来包装读取器,如:sqlCmd.ExecuteReader().AsMyReader().什么AsMyReader()会做的是返回一个自定义IDataReader,它的东西和委托到实际的sqlDataReader.
2使用现有的助手库
我不太清楚你在阅读内容时想要实现什么,但是在这个空间中存在着很好的图书馆.没有必要提出自己的解决方案.
FastMember(Nuget)允许在任何IEnumerable< T>之间创建IDataReader接口.或DataTable.它被轻易地用作sqlBulkCopy的种子,以便最大程度地插入数据.性能进入sql Server表.