An OracleBlob object is an object that has a reference to BLOB data. It provides methods for performing operations on BLOBs.

Class Inheritance

System.Object

  System.MarshalByRefObject

    System.IO.Stream

      Oracle.DataAccess.Types.OracleBlob

Declaration

// C#
public sealed class OracleBlob : Stream, ICloneable, INullable

Requirements

Thread Safety

All public static methods are thread-safe, although instance methods do not guarantee thread safety.

Example

// C#
 
using System;
using Oracle.DataAccess.Client;
using Oracle.DataAccess.Types;
 
class OracleBlobSample
{
  static void Main()
  {
    string constr = "User Id=scott;Password=tiger;Data Source=oracle";
    OracleConnection con = new OracleConnection(constr);
    con.Open();
 
    OracleBlob blob = new OracleBlob(con);
      
    // Write 4 bytes from writeBuffer, starting at buffer offset 0
    byte[] writeBuffer = new byte[4] {1, 2, 3, 4};
    blob.Write(writeBuffer, 0, 4);    
 
    // Append first 2 bytes from writeBuffer {1, 2} to the oracleBlob
    blob.Append(writeBuffer, 0, 2);
 
    // Prints "blob.Length  = 6"
    Console.WriteLine("blob.Length  = " + blob.Length);
 
    // Reset the Position for the Read
    blob.Position = 0;
 
    // Read 6 bytes into readBuffer, starting at buffer offset 0
    byte[] readBuffer = new byte[6];       
    int bytesRead = blob.Read(readBuffer, 0, 6);
    
    // Prints "bytesRead    = 6"
    Console.WriteLine("bytesRead    = " + bytesRead);    
 
    // Prints "readBuffer   = 123412"
    Console.Write("readBuffer   = ");
    for(int index = 0; index <  readBuffer.Length; index++)
    {
      Console.Write(readBuffer[index]);
    }
    Console.WriteLine();
        
    // Search for the 2nd occurrence of a byte pattern '12'
    // starting from byte offset 0 in the OracleBlob
    byte[] pattern = new byte[2] {1, 2};
    long posFound = blob.Search(pattern, 0, 2);
 
    // Prints "posFound     = 5" 
    Console.WriteLine("posFound     = " + posFound);
 
    // Erase 4 bytes of data starting at byte offset 1
    // Sets bytes to zero
    blob.Erase(1, 4);
 
    byte[] erasedBuffer = blob.Value;    
 
    //Prints "erasedBuffer = 100002"
    Console.Write("erasedBuffer = ");
    for(int index = 0; index < erasedBuffer.Length; index++)
    {
      Console.Write(erasedBuffer[index]);
    }
    Console.WriteLine();
 
    blob.Close();
    blob.Dispose();
 
    con.Close();
    con.Dispose();
  }
}