下载Oracle数据库中的Blob二进制文件，实例！

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将Oracle数据库中HR方案下的TESTFILEUPLOAD表中的文件下载至系统临时目录。

void downloadFile()
{
OracleConnection objOcon = new OracleConnection("user id=system;Data Source=tsems;password=system");

OracleCommand objOcmd = new OracleCommand();

objOcmd.Connection = objOcon;

objOcmd.CommandText = "SELECT * FROM HR.TESTFILEUPLOAD WHERE PKID='2006'";

FileStream objFs;

BinaryWriter objBw;

int bufferSize = 260;

byte [] outByte = new byte[bufferSize];

long retval;

long startIndex = 0;

string fileName = "";

objOcon.Open();

OracleDataReader objDr = objOcmd.ExecuteReader(CommandBehavior.SequentialAccess);
objDr.Read();

fileName = objDr["FILENAME"].ToString();

objFs = new FileStream(Path.GetTempPath()+fileName, FileMode.OpenOrCreate,FileAccess.Write);

objBw = new BinaryWriter(objFs);

startIndex = 0;

retval = objDr.GetBytes(8, startIndex, outByte, 0, bufferSize);

   while ( retval == bufferSize)
   {
    objBw.Write(outByte);

objBw.Flush();

startIndex += bufferSize;

retval = objDr.GetBytes(8, startIndex, outByte, 0, bufferSize);
}

objBw.Write(outByte, 0, (int)retval -1);

objBw.Flush();

objBw.Close();

objFs.Close();

bjDr.Close();

objOcon.Close();
}