Represents LOB data type stored on an Oracle server.
In this example two functions are presented. First can upload a file onto a server, and second can retrieve a LOB field and paste it into a file. Notice that two classes used here (BinaryWriter and BinaryReader) to provide more flexible stream manipulation are actually redundant for simple data transfer operations.
The following table is used for the sample:
CREATE TABLE Pictures (
ID NUMBER(4) NOT NULL PRIMARY KEY,
PicName VARCHAR2(50),
Picture BLOB
)
public void DownloadBlob(OracleConnection myConnection)
{
OracleCommand myCommand = new OracleCommand("SELECT * FROM Pictures", myConnection);
myConnection.Open();
OracleDataReader myReader = myCommand.ExecuteReader(System.Data.CommandBehavior.Default);
try
{
while (myReader.Read())
{
OracleLob myLob = myReader.GetOracleLob(myReader.GetOrdinal("Picture"));
if (!myLob.IsNull)
{
string FN = myReader.GetString(myReader.GetOrdinal("PicName"));
FileStream fs = new FileStream("D:\\Tmp\\" + FN + ".bmp", FileMode.Create);
BinaryWriter w = new BinaryWriter(fs);
w.Write((byte[])myLob.Value);
w.Close();
fs.Close();
Console.WriteLine(FN + " downloaded.");
}
}
}
finally
{
myReader.Close();
myConnection.Close();
}
}
public void UploadBlob(OracleConnection myConnection)
{
FileStream fs = new FileStream("D:\\Tmp\\_Water.bmp", FileMode.Open, FileAccess.Read);
BinaryReader r = new BinaryReader(fs);
myConnection.Open();
OracleLob myLob = new OracleLob(myConnection,OracleDbType.Blob);
int streamLength = (int)fs.Length;
myLob.Write(r.ReadBytes(streamLength), 0, streamLength);
OracleCommand myCommand = new OracleCommand("INSERT INTO Pictures (ID, PicName, Picture) VALUES(1,'Water',:Pictures)", myConnection);
OracleParameter myParam = myCommand.Parameters.Add("Pictures", OracleDbType.Blob);
myParam.OracleValue = myLob;
try
{
Console.WriteLine(myCommand.ExecuteNonQuery() + " rows affected.");
}
finally
{
myConnection.Close();
r.Close();
fs.Close();
}
}
Public Sub DownloadBlob(ByVal myConnection As OracleConnection)
Dim myCommand As New OracleCommand("SELECT * FROM Pictures", myConnection)
myConnection.Open()
Dim myReader As OracleDataReader = myCommand.ExecuteReader(System.Data.CommandBehavior.Default)
Try
While myReader.Read()
Dim myLob As OracleLob = myReader.GetOracleLob(myReader.GetOrdinal("Picture"))
If Not myLob.IsNull Then
Dim FN As String = myReader.GetString(myReader.GetOrdinal("PicName"))
Dim fs As FileStream = New FileStream("D:\Tmp\" + FN + ".bmp", FileMode.Create)
Dim w As BinaryWriter = New BinaryWriter(fs)
w.Write(myLob.Value)
w.Close()
fs.Close()
Console.WriteLine(String.Concat(FN, " downloaded."))
End If
End While
Finally
myReader.Close()
myConnection.Close()
End Try
End Sub
Public Sub UploadBlob(ByVal myConnection As OracleConnection)
Dim fs As FileStream = New FileStream("D:\Tmp\_Water.bmp", FileMode.Open, FileAccess.Read)
Dim r As BinaryReader = New BinaryReader(fs)
myConnection.Open()
Dim myLob As OracleLob = New OracleLob(myConnection, OracleDbType.Blob)
Dim streamLength As Int32 = fs.Length
myLob.Write(r.ReadBytes(streamLength), 0, streamLength)
Dim myCommand As OracleCommand = New OracleCommand("INSERT INTO Pictures (ID, PicName, Picture) VALUES(1,'Water',:Pictures)", myConnection)
Dim myParam As OracleParameter = myCommand.Parameters.Add("Pictures", OracleDbType.Blob)
myParam.OracleValue = myLob
Try
Console.WriteLine(myCommand.ExecuteNonQuery() & " rows affected.")
Finally
myConnection.Close()
r.Close()
fs.Close()
End Try
End Sub
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2