OracleBFile Class

In This Topic

Represents a managed OracleBFile object to work with the Oracle BFILE data type.

Syntax

Visual Basic
C#

'Declaration
 
Public NotInheritable Class OracleBFile 
   Inherits OracleLob
   Implements System.Data.SqlTypes.INullable, System.ICloneable, System.IComparable, System.IDisposable

public sealed class OracleBFile : OracleLob, System.Data.SqlTypes.INullable, System.ICloneable, System.IComparable, System.IDisposable

Remarks

The Oracle BFILE data type represents a reference to the physical file in the operating system where Oracle is installed. Maximum size of the file is 4 gigabytes. The OracleDbType.BFile data type cannot be modified and provides read-only access to data. So write-oriented methods of OracleBFile class are not supported.

To read data use Read and OracleLob.Seek methods.

Example

The following sample shows how the OracleBFile class can be used. We insert a BFile object to the database and then print the content of the corresponding file on the physical drive. To run the sample, you need to create the BFileTable table first:

CREATE TABLE BFileTable (
  id NUMBER,
  bf BFILE)

csharp

// Open a connection
OracleConnection con = new OracleConnection("Server = Ora; User Id = Scott; Password = tiger;");
con.Open();

OracleCommand com = new OracleCommand();
com.Connection = con;

// Create an Oracle directory corresponding to the folder containing the file.
com.CommandText = "CREATE OR REPLACE DIRECTORY Images as 'D:\\images\\'";
com.ExecuteNonQuery();

// Create an OracleBFile object.
// Note that the directory name should be in upper case. 
// Otherwise, it will be case-sensitive and may cause errors.
OracleBFile bFile = new OracleBFile(con, "IMAGES", "image001.jpg");

// Insert the OracleBFile object to the database.
com.CommandText = "INSERT INTO BFileTable VALUES (1, :bfile)";
com.Parameters.Add(new OracleParameter("bfile", bFile));
com.ExecuteNonQuery();

// Retrieve data from the table.
com.Parameters.Clear();
com.CommandText = "SELECT * FROM BFileTable";
OracleDataReader reader = com.ExecuteReader();

while (reader.Read()) {

        // Get BFiles from the reader and print a part of their content.
        bFile = reader.GetOracleBFile(1);
        bFile.OpenFile();

        byte[] buffer = new byte[100];
        bFile.Read(buffer, 0, 100);
        foreach(byte bt in buffer)
                   Console.Write(bt + " ");

         Console.WriteLine();

        bFile.Close();
}

Visual Basic

' Open a connection
Dim con = New OracleConnection("Server = Ora; User Id = Scott; Password = tiger;")
con.Open()

Dim com = New OracleCommand()
com.Connection = con

' Create an Oracle directory corresponding to the folder containing the file.
com.CommandText = "CREATE OR REPLACE DIRECTORY Images as 'D:\\Images\\'"
com.ExecuteNonQuery()

' Create an OracleBFile object.
' Note that the directory name should be in upper case. 
' Otherwise, it will be case-sensitive and may cause errors.
Dim bFile As OracleBFile = New OracleBFile(con, "IMAGES", "image001.jpg")

' Insert the OracleBFile object to the database.
com.CommandText = "INSERT INTO BFileTable VALUES (1, :bfile)"
com.Parameters.Add(New OracleParameter("bfile", bFile))
com.ExecuteNonQuery()

' Retrieve data from the table.
com.Parameters.Clear()
com.CommandText = "SELECT * FROM BFileTable"
Dim reader = com.ExecuteReader()

While reader.Read()

    ' Get BFiles from the reader and print a part of their content.
    bFile = reader.GetOracleBFile(1)
    bFile.OpenFile()

    Dim buffer As Byte() = New Byte(100) {}
    bFile.Read(buffer, 0, 100)
    For Each bt As Byte In buffer
        Console.Write(bt & " ")
    Next

    Console.WriteLine()

    bFile.Close()

End While

Inheritance Hierarchy

System.Object
   System.MarshalByRefObject
      System.IO.Stream
         Devart.Data.Oracle.OracleLob
            Devart.Data.Oracle.OracleBFile

Reference

OracleBFile Members
Devart.Data.Oracle Namespace

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