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1、数据流处理1. 从数据库读取数据二进制流创建文件 publicstaticstring LoadFile(string filePath, string fileName) try if(CreateFolder(System.Environment .CurrentDirectory + filePath) if (!System.IO.File .Exists(System.Environment .CurrentDirectory + filePath + “ + fileName) / 创建文件对象以创建文件的形式打开文件System.IO.FileStream fs = new Sy
2、stem.IO. FileStream (System. Environment .CurrentDirectory + filePath + “ + fileName, System.IO.FileMode.Create); byte Data = new byte 0; object cell = AppServer.YsServiceBaseClient.DN_YS_SelectDATACELL( “YS“, fileName); Data = (byte )cell; / 将数组的内容写进文件fs.Write(Data, 0, Data.Length); / 关闭文件fs.Close(
3、); catch /return System.IO.Path.GetFullPath(filePath + “ + fileName); return System. Environment .CurrentDirectory + filePath + “ + fileName; 2. 把文件以二进制流的方式写进数据库 publicstaticvoid SaveFilecell() OpenFileDialog openFileDialog = new OpenFileDialog (); /openFileDialog.InitialDirectory = Environment.GetF
4、olderPath(Environment.SpecialFolder.Personal); openFileDialog.InitialDirectory = System.Environment .CurrentDirectory + “data“ ; openFileDialog.Filter = “CELL文件(*.cll)|*.cll|XML文件 (*.xml)|*.xml|所有文件 (*.*)|*.*“; if (openFileDialog.ShowDialog() = DialogResult .OK) string FileName = openFileDialog.File
5、Name; System.IO.FileInfo myFile = new System.IO. FileInfo(FileName); System.IO.FileStream fs = new System.IO. FileStream (FileName, System.IO.FileMode.Open); int length = (int )fs.Length; byte fileData = new byte length; try fs.Read(fileData, 0, length); AppServer.YsServiceBaseClient.DN_YS_InsertDAT
6、ACELL( “YS“, myFile.Name, fileData); MessageBox .Show(“ 文件保存成功 “ , “ 系统信息 “ , MessageBoxButtons.OK, MessageBoxIcon.Information); catch ( Exception ex) throw new Exception ( “文件保存失败，原因： “ + ex.Message); finally fs.Close(); 3.数据流在数据库内部的使用表结构表数据转移数据库数据时Select data=data from dbo.a.DN_GY_DA TAINSERT INTO
7、 dbo.b.dn_gy_data(data) values data 这种方法不正确正确方法如下：ALTERPROCEDURE dbo. P_DN_GY_SelectSJJB ( Module VARCHAR( 20 ),- 模块Where VARCHAR( 1000 )- 条件/* EXEC P_DN_GY_SelectSJJB ZW, */ ) AS BEGIN SET NOCOUNT ON createtable #Temp ( ID INTIDENTITY( 1, 1)PRIMARYKEY, Module VARCHAR( 20 )NULL, Number VARCHAR( 100
8、)NULL, Data varbinary( max)NULL ) if Where = begin insertinto#Temp ( Module, Number , Data )selectModule, Number , Data from DN_GY_DATA where Module = Module end else begin exec ( insert into #Temp(Module,Number,Data) select Module,Number,Data from DN_GY_DATA where Module = Module and + Where) end d
9、eclare i int, j int, number varchar( 100 ), data varbinary( max) select i =1, j=count( 1)from #temp while i =j begin select number=number , data =data from #temp where id=i printinsert into DN_GY_DATA(Module,Number,Data) values(+Module +,+number +, print data print) set i =i+1 end droptable #Temp SET NOCOUNT OFF END
