怎样把任意一个文件读到oracle的blob里，急啊！！

to saucer(思归, MS .NET MVP) 有没有c＃的例子？

要把sr转成byte[]byte[] bytes = new byte[(int)sr.Length];
sr.Read(bytes, 0, bytes.Length);
sr.Close();//
myCommand.Parameters["@stream"].Value=bytes;

to panyee(快乐王子)
好像没有StreamReader.Length的方法吧？

用FileStream fs = new FileStream("c:\\1.dat", FileMode.Open, FileAccess.Read);

用FileSteam fs = new FileStream("c:\\1.dat", FileMode.Open, FileAccess.Read);fs.Length;

to  panyee(快乐王子) 谢了！
向oracle添加成功了，但从oracle读出来的时候出错：
未指定的错误发生了一个 Oracle 错误，但无法从 Oracle 中检索错误信息。数据类型不被支持。
表是test（id number ，stream blob）
写入stream的代码：
                           FileStream fs = File.OpenRead("c:\\1.txt");
string   strConnectDb;
byte[] bytes = new byte[(int)fs.Length];
fs.Read(bytes, 0, bytes.Length);
fs.Close();
System.Data.OleDb.OleDbConnection  oleConnect = null;
strConnectDb = "Provider=MSDAORA;Password=manager;User ID=system;Data Source=zengting";
oleConnect=new OleDbConnection(strConnectDb);
oleConnect.Open();
string str="insert into test values(stream.nextval,?)";
OleDbCommand myCommand=new OleDbCommand(str,oleConnect);
myCommand.Parameters.Add(new OleDbParameter("@blob",OleDbType.Binary,bytes.Length,"blob"));
myCommand.Parameters["@blob"].Value=bytes;
myCommand.ExecuteNonQuery();
读出stream的代码：
                           string   strConnectDb;
System.Data.OleDb.OleDbConnection  oleConnect = null;
strConnectDb  = "Provider=MSDAORA;Password=manager;User ID=system;Data Source=zen";
oleConnect=new OleDbConnection(strConnectDb);
oleConnect.Open();
string str="select stream from test where ID=2";
OleDbCommand myCommand=new OleDbCommand (str,oleConnect);
OleDbDataReader myReader=myCommand.ExecuteReader();//出错
请问，怎样读出来写到一个新的文件里？

读的时候这样就出错？不太可能吧？
如果读出正确的话，用下列语句保存byte[] bytes = (byte[])myReader["stream"];然后FileStream fs = new FileStream("c:\\456.txt",
FileMode.OpenOrCreate, FileAccess.Write);
fs.Write(bytes, 0, bytes.Length);
fs.Flush();
fs.Close();

你的代码中：
test（id number ，stream blob）
myCommand.Parameters.Add(new OleDbParameter("@blob",OleDbType.Binary,bytes.Length,"blob"));你的参数应该要写成
("@blob",OleDbType.Binary,bytes.Length,"stream"));

to panyee(快乐王子) ( )
OleDbDataReader myReader=myCommand.ExecuteReader();
这句已经出错了。出错信息：未指定的错误发生了一个 Oracle 错误，但无法从 Oracle 中检索错误信息。数据类型不被支持。

我把select语句改成：select id from test where ID=2
OleDbDataReader myReader=myCommand.ExecuteReader();就不出错了，这说明是转换的问题。
我用byte[] bytes=(byte[])myCommand.ExecuteReader();编译不过，提示不能转换成byte[]

如果直接在sql plus里执行是什么结果？

可以啊!我用toad，select语句没有问题
select stream from test;
STREAM
-----------
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
<BLOB>
32 rows selected

但不知道stream字段里是否有数据？

看来这个字段非得请Oracle Provider for .Net出马了，OleDb无法胜任

oledb不能读oracle的blob字段？
还有其他方法吗？Oracle Provider for .Net我没有用过，行吗？

Oracle.net组件里的例子   ///////////////////////////////////////////////////////////////
   // ReadLobExample
   //
   ///////////////////////////////////////////////////////////////
   public static void ReadLobExample(OracleCommand cmd)
   {
      int actual = 0;      //Select some data.
      //   Table Schema:
      //      "CREATE TABLE tablewithlobs (a int, b BLOB, c CLOB, d NCLOB)";
      //      "INSERT INTO tablewithlobs values (1, 'AA', 'AAA', N'AAAA')";
      cmd.CommandText   = "SELECT * FROM tablewithlobs";
      OracleDataReader reader = cmd.ExecuteReader();
      using(reader)
      {
         //Obtain the first row of data.
         reader.Read();

         //Obtain the LOBs (all 3 varieties).
         OracleLob BLOB   = reader.GetOracleLob(1/*0:based ordinal*/);
         OracleLob CLOB  = reader.GetOracleLob(2/*0:based ordinal*/);
         OracleLob NCLOB = reader.GetOracleLob(3/*0:based ordinal*/);         //Example - Reading binary data (in chunks).
         byte[] buffer = new byte[100];
         while((actual = blob.Read(buffer, 0/*buffer offset*/, buffer.Length/*count*/)) >0)
            Console.WriteLine(blob.LobType + ".Read(" + buffer + ", " + buffer.Length + ") => " + actual);         //Example - Reading CLOB/NCLOB data (in chunks).
         //Note: You can read character data as raw Unicode bytes (using OracleLob.Read as in the above example).
         //However, because the OracleLob object inherits directly from the .Net stream object,
         //all the existing classes that manipluate streams can also be used. For example, the
         //.Net StreamReader makes converting the raw bytes into actual characters easier.
         StreamReader streamreader = new StreamReader(clob, Encoding.Unicode);
         char[] cbuffer = new char[100];
         while((actual = streamreader.Read(cbuffer, 0/*buffer offset*/, cbuffer.Length/*count*/)) >0)
            Console.WriteLine(CLOB.LobType + ".Read(" + new string(cbuffer, 0, actual) + ", " + cbuffer.Length + ") => " + actual);         //Example - Reading data (all at once).
         //You could use StreamReader.ReadToEnd to obtain all the string data,or simply
         //call OracleLob.Value to obtain a contiguous allocation of all the data.
         Console.WriteLine(NCLOB.LobType + ".Value => " + NCLOB.Value);
      }
   }

在.NET 1.0 里System.Data.OracleClient不支持远程访问,建议你用LongRaw类型

i come!useing:
system.io.filestream f = new filestream(filepath,filmode.open)
if
{
  bye[] bt = new byte[f.length];
  int d = f.length;
  f.read(bt,0,d);
  oracleConnection conn = new oracleconnection("string");
  conn.open()
  oraclecommand commd = new oraclecommand;
  commd.connection = conn;
  sql = "insert tba value(:O_blob)";
  system.data.oracleclient.oracleparameter op = new oracleparameter();
  op.oracletype = oracletype.blob;
  op.parametername = ":o_blob";
  op.value = bt;
  commd.parameters.add(op);
  commd.exectenoquery();
  conn.clsoe();
}
need:
system.data.oracleclient.dll

this in .net framework1.1

调试易

怎样把任意一个文件读到oracle的blob里，急啊！！

解决方案 »