Oracle8i Application Developer's Guide - Large Objects (LOBs)
Release 2 (8.1.6)

Part Number A76940-01

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External LOBs (BFILEs), 39 of 41


Close a BFILE with CLOSE

Figure 11-35 Use Case Diagram: Close an Open BFILE with CLOSE


See Also:

"Use Case Model: External LOBs (BFILEs)" for all basic operations of External LOBs (BFILES). 

Purpose

This procedure describes how to close a BFILE with CLOSE.

Usage Notes

Not applicable.

Syntax

See Chapter 3, "LOB Programmatic Environments" for a list of available functions in each programmatic environment. Use the following syntax references for each programmatic environment:

Scenario

This example should be read in conjunction with the example of opening a BFILE -- in this case, closing the BFILE associated with Lincoln_photo.

Examples

PL/SQL (DBMS_LOB Package): Close a BFile with CLOSE

/* Note that the example procedure closeBFILE_procTwo is not part of the 
   DBMS_LOB package: */
CREATE OR REPLACE PROCEDURE closeBFILE_procTwo IS
   Lob_loc    BFILE := BFILENAME('PHOTO_DIR', 'Lincoln_photo');
BEGIN
   DBMS_LOB.OPEN(Lob_loc, DBMS_LOB.LOB_READONLY);
   /* ...Do some processing. */
   DBMS_LOB.CLOSE(Lob_loc);
END;

C (OCI): Close a BFile with CLOSE

void BfileClose(envhp, errhp, svchp, stmthp) 
OCIEnv       *envhp; 
OCIError     *errhp; 
OCISvcCtx    *svchp; 
OCIStmt      *stmthp; 
{ 

   OCILobLocator *bfile_loc; 
 
   /* Allocate the locator descriptors */ 
   (void) OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &bfile_loc,
                             (ub4) OCI_DTYPE_FILE,  
                             (size_t) 0, (dvoid **) 0);

   checkerr(errhp, OCILobFileSetName(envhp, errhp, &bfile_loc,
                        (OraText *) "PHOTO_DIR", (ub2) strlen("PHOTO_DIR"),
                        (OraText *) "Lincoln_photo",
                        (ub2) strlen("Lincoln_photo")));

   checkerr(errhp, OCILobOpen(svchp, errhp, bfile_loc,
                                          (ub1) OCI_LOB_READONLY));

   checkerr(errhp, OCILobClose(svchp, errhp, bfile_loc));

   /* Free the locator descriptor */ 
   OCIDescriptorFree((dvoid *)bfile_loc, (ub4)OCI_DTYPE_FILE); 
}

COBOL (Pro*COBOL): Close a BFile with CLOSE

       IDENTIFICATION DIVISION.
       PROGRAM-ID. BFILE-CLOSE.
       ENVIRONMENT DIVISION.
       DATA DIVISION.
       WORKING-STORAGE SECTION.

       01  USERID   PIC X(11) VALUES "SAMP/SAMP".
       01  BFILE1         SQL-BFILE.
       01  DIR-ALIAS      PIC X(30) VARYING.
       01  FNAME          PIC X(20) VARYING.
       01  ORASLNRD        PIC 9(4).

           EXEC SQL INCLUDE SQLCA END-EXEC.
           EXEC ORACLE OPTION (ORACA=YES) END-EXEC.
           EXEC SQL INCLUDE ORACA END-EXEC.

       PROCEDURE DIVISION.
       BFILE-CLOSE.

           EXEC SQL WHENEVER SQLERROR DO PERFORM SQL-ERROR END-EXEC.
           EXEC SQL CONNECT :USERID END-EXEC.

      * Allocate and initialize the BFILE locators: 
           EXEC SQL ALLOCATE :BFILE1 END-EXEC.

      * Set up the directory and file information: 
           MOVE "PHOTO_DIR" TO DIR-ALIAS-ARR.
           MOVE 9 TO DIR-ALIAS-LEN.
           MOVE "Lincoln_photo" TO FNAME-ARR.
           MOVE 13 TO FNAME-LEN.
 
           EXEC SQL 
                LOB FILE SET :BFILE1
                DIRECTORY = :DIR-ALIAS, FILENAME = :FNAME END-EXEC.

           EXEC SQL
                LOB OPEN :BFILE1 READ ONLY END-EXEC.

      * Close the LOB: 
           EXEC SQL LOB CLOSE :BFILE1 END-EXEC.

      * And free the LOB locator: 
           EXEC SQL FREE :BFILE1 END-EXEC.
           STOP RUN.

       SQL-ERROR.
           EXEC SQL WHENEVER SQLERROR CONTINUE END-EXEC.
           MOVE ORASLNR TO ORASLNRD.
           DISPLAY " ".
           DISPLAY "ORACLE ERROR DETECTED ON LINE ", ORASLNRD, ":".
           DISPLAY " ".
           DISPLAY SQLERRMC.
           EXEC SQL ROLLBACK WORK RELEASE END-EXEC.
           STOP RUN.

C/C++ (Pro*C/C++): Close a BFile with CLOSE

/* Pro*C/C++ has only one form of CLOSE for BFILEs.  Pro*C/C++ has no
   FILE CLOSE statement.  A simple CLOSE statement is used instead: */

#include <oci.h>
#include <stdio.h>
#include <sqlca.h>

void Sample_Error()
{
  EXEC SQL WHENEVER SQLERROR CONTINUE;
  printf("%.*s\n", sqlca.sqlerrm.sqlerrml, sqlca.sqlerrm.sqlerrmc);
  EXEC SQL ROLLBACK WORK RELEASE;
  exit(1);
}

void closeBFILE_proc()
{
  OCIBFileLocator *Lob_loc;
  char *Dir = "PHOTO_DIR", *Name = "Lincoln_photo";

  EXEC SQL WHENEVER SQLERROR DO Sample_Error();
  EXEC SQL ALLOCATE :Lob_loc;
  EXEC SQL LOB FILE SET :Lob_loc DIRECTORY = :Dir, FILENAME = :Name;
  EXEC SQL LOB OPEN :Lob_loc READ ONLY;
  /* ... Do some processing */
  EXEC SQL LOB CLOSE :Lob_loc;
  EXEC SQL FREE :Lob_loc;
}

void main()
{
  char *samp = "samp/samp";
  EXEC SQL CONNECT :samp;
  closeBFILE_proc();
  EXEC SQL ROLLBACK WORK RELEASE;
}

Visual Basic (OO4O): Close a BFile with CLOSE

Dim MySession As OraSession
Dim OraDb As OraDatabase

Dim OraDyn As OraDynaset, OraMusic As OraBfile, amount_read%, chunksize%, chunk

Set MySession = CreateObject("OracleInProcServer.XOraSession")
Set OraDb = MySession.OpenDatabase("exampledb", "scott/tiger", 0&)

chunksize = 32767
Set OraDyn = OraDb.CreateDynaset("select * from Multimedia_tab", ORADYN_DEFAULT)
Set OraMusic = OraDyn.Fields("Music").Value
 
If OraMusic.IsOpen Then
   'Processing given that the file is already open
   OraMusic.Close
End If
 

Java (JDBC): Close a BFile with CLOSE

import java.io.InputStream;
import java.io.OutputStream;

// Core JDBC classes: 
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

// Oracle Specific JDBC classes: 
import oracle.sql.*;
import oracle.jdbc.driver.*;

public class Ex4_48
{
  public static void main (String args [])
       throws Exception
  {
    // Load the Oracle JDBC driver: 
    DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());

    // Connect to the database: 
    Connection conn =
      DriverManager.getConnection ("jdbc:oracle:oci8:@", "samp", "samp");

    conn.setAutoCommit (false);

    // Create a Statement: 
    Statement stmt = conn.createStatement ();
    try
    {
     BFILE src_lob = null;
       ResultSet rset = null;

       rset = stmt.executeQuery (
       "SELECT BFILENAME('PHOTO_DIR', 'Lincoln_photo') FROM DUAL");
       OracleCallableStatement cstmt = null;
       if (rset.next())
       {
          src_lob = ((OracleResultSet)rset).getBFILE (1);
	  cstmt = (OracleCallableStatement)conn.prepareCall 
	       ("begin dbms_lob.open (?,dbms_lob.lob_readonly); end;");
          cstmt.registerOutParameter(1,OracleTypes.BFILE);
          cstmt.setBFILE (1, src_lob);
          cstmt.execute();
          src_lob = cstmt.getBFILE(1);
          System.out.println ("the file is now open");
       }

       // Close the BFILE, statement and connection: 
       cstmt = (OracleCallableStatement)
       conn.prepareCall ("begin dbms_lob.close(?); end;");
       cstmt.setBFILE(1,src_lob);
       cstmt.execute();
       stmt.close();
       conn.commit();
       conn.close();
    }
    catch (SQLException e)
    {
       e.printStackTrace();
    }
  }
}

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