Oracle8i Application Developer's Guide - Large Objects (LOBs) Release 2 (8.1.6) Part Number A76940-01 |
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Internal Persistent LOBs, 21 of 42
See: "Use Case Model: Internal Persistent LOBs Basic Operations", for all basic operations of Internal Persistent LOBs.: |
This procedure describes how to compare all or part of two LOBs.
Not applicable.
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:
The following examples compare two frames from the archival table VideoframesLib_tab
to see whether they are different and, depending on the result of the comparison, inserts the Frame
into the Multimedia_tab
.
Examples are provided in the following programmatic environments:
/* Note that the example procedure compareTwoLOBs_proc is not part of the DBMS_LOB package: */ CREATE OR REPLACE PROCEDURE compareTwoLOBs_proc IS Lob_loc1 BLOB; Lob_loc2 BLOB; Amount INTEGER := 32767; Retval INTEGER; BEGIN /* Select the LOB: */ SELECT Frame INTO Lob_loc1 FROM Multimedia_tab WHERE Clip_ID = 1; SELECT Frame INTO Lob_loc2 FROM Multimedia_tab WHERE Clip_ID = 2; /* Opening the LOB is optional: */ DBMS_LOB.OPEN (Lob_loc1, DBMS_LOB.LOB_READONLY); DBMS_LOB.OPEN (Lob_loc2, DBMS_LOB.LOB_READONLY); /* Compare the two frames: */ retval := DBMS_LOB.COMPARE(Lob_loc1, Lob_loc2, Amount, 1, 1); IF retval = 0 THEN DBMS_OUTPUT.PUT_LINE('Processing for equal frames'); ELSE DBMS_OUTPUT.PUT_LINE('Processing for non-equal frames'); END IF; /* Closing the LOB is mandatory if you have opened it: */ DBMS_LOB.CLOSE (Lob_loc1); DBMS_LOB.CLOSE (Lob_loc2); END;
IDENTIFICATION DIVISION. PROGRAM-ID. COMPARE. ENVIRONMENT DIVISION. DATA DIVISION. WORKING-STORAGE SECTION. 01 USERID PIC X(11) VALUES "SAMP/SAMP". 01 BLOB1 SQL-BLOB. 01 BLOB2 SQL-BLOB. 01 BUFFER2 PIC X(32767) VARYING. 01 RET PIC S9(9) COMP. 01 AMT PIC S9(9) COMP. 01 POS PIC S9(9) COMP VALUE 1024. 01 OFFSET PIC S9(9) COMP VALUE 1. EXEC SQL VAR BUFFER2 IS VARRAW(32767) END-EXEC. EXEC SQL INCLUDE SQLCA END-EXEC. PROCEDURE DIVISION. COMPARE-BLOB. EXEC SQL WHENEVER SQLERROR DO PERFORM SQL-ERROR END-EXEC. EXEC SQL CONNECT :USERID END-EXEC. * Allocate and initialize the BLOB locators: EXEC SQL ALLOCATE :BLOB1 END-EXEC. EXEC SQL ALLOCATE :BLOB2 END-EXEC. EXEC SQL WHENEVER NOT FOUND GOTO END-OF-BLOB END-EXEC. EXEC SQL SELECT FRAME INTO :BLOB1 FROM MULTIMEDIA_TAB M WHERE M.CLIP_ID = 1 END-EXEC. EXEC SQL SELECT FRAME INTO :BLOB2 FROM MULTIMEDIA_TAB M WHERE M.CLIP_ID = 2 END-EXEC. * Open the BLOBs for READ ONLY: EXEC SQL LOB OPEN :BLOB1 READ ONLY END-EXEC. EXEC SQL LOB OPEN :BLOB2 READ ONLY END-EXEC. * Execute PL/SQL to get COMPARE functionality: MOVE 4 TO AMT. EXEC SQL EXECUTE BEGIN :RET := DBMS_LOB.COMPARE(:BLOB1,:BLOB2,:AMT,1,1); END; END-EXEC. IF RET = 0 * Logic for equal BLOBs goes here DISPLAY "BLOBs are equal" ELSE * Logic for unequal BLOBs goes here DISPLAY "BLOBs are not equal" END-IF. EXEC SQL LOB CLOSE :BLOB1 END-EXEC. EXEC SQL LOB CLOSE :BLOB2 END-EXEC. END-OF-BLOB. EXEC SQL WHENEVER NOT FOUND CONTINUE END-EXEC. EXEC SQL FREE :BLOB1 END-EXEC. EXEC SQL FREE :BLOB2 END-EXEC. EXEC SQL ROLLBACK WORK RELEASE END-EXEC. STOP RUN. SQL-ERROR. EXEC SQL WHENEVER SQLERROR CONTINUE END-EXEC. DISPLAY " ". DISPLAY "ORACLE ERROR DETECTED:". DISPLAY " ". DISPLAY SQLERRMC. EXEC SQL ROLLBACK WORK RELEASE END-EXEC. STOP RUN.
#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 compareTwoLobs_proc() { OCIBlobLocator *Lob_loc1, *Lob_loc2; int Amount = 32767; int Retval; EXEC SQL WHENEVER SQLERROR DO Sample_Error(); /* Allocate the LOB locators: */ EXEC SQL ALLOCATE :Lob_loc1; EXEC SQL ALLOCATE :Lob_loc2; /* Select the LOBs: */ EXEC SQL SELECT Frame INTO :Lob_loc1 FROM Multimedia_tab WHERE Clip_ID = 1; EXEC SQL SELECT Frame INTO :Lob_loc2 FROM Multimedia_tab WHERE Clip_ID = 2; /* Opening the LOBs is Optional: */ EXEC SQL LOB OPEN :Lob_loc1 READ ONLY; EXEC SQL LOB OPEN :Lob_loc2 READ ONLY; /* Compare the two Frames using DBMS_LOB.COMPARE() from within PL/SQL: */ EXEC SQL EXECUTE BEGIN :Retval := DBMS_LOB.COMPARE(:Lob_loc1, :Lob_loc2, :Amount, 1, 1); END; END-EXEC; if (0 == Retval) printf("The frames are equal\n"); else printf("The frames are not equal\n"); /* Closing the LOBs is mandatory if you have opened them: */ EXEC SQL LOB CLOSE :Lob_loc1; EXEC SQL LOB CLOSE :Lob_loc2; /* Release resources held by the locators: */ EXEC SQL FREE :Lob_loc1; EXEC SQL FREE :Lob_loc2; } void main() { char *samp = "samp/samp"; EXEC SQL CONNECT :samp; compareTwoLobs_proc(); EXEC SQL ROLLBACK WORK RELEASE; }
Dim MySession As OraSession Dim OraDb As OraDatabase Set MySession = CreateObject("OracleInProcServer.XOraSession") Set OraDb = MySession.OpenDatabase("exampledb", "samp/samp", 0&) Dim OraDyn as OraDynaset, OraSound1 as OraBLOB, OraSoundClone as OraBLOB Set OraDyn = OraDb.CreateDynaset( "SELECT * FROM Multimedia_tab ORDER BY clip_id", ORADYN_DEFAULT) Set OraSound1 = OraDyn.Fields("Sound").Value 'Clone it for future reference Set OraSoundClone = OraSound1.Clone 'Lets go to the next row and compare LOBs OraDyn.MoveNext MsgBox CBool(OraSound1.Compare(OraSoundClone, OraSoundClone.size, 1, 1))
import java.io.InputStream; import java.io.OutputStream; // Core JDBC classes: import java.sql.DriverManager; import java.sql.Connection; import java.sql.Types; 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 Ex2_87 { static final int MAXBUFSIZE = 32767; 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"); // It's faster when auto commit is off: conn.setAutoCommit (false); // Create a Statement: Statement stmt = conn.createStatement (); try { BLOB lob_loc1 = null; BLOB lob_loc2 = null; ResultSet rset = stmt.executeQuery ( "SELECT frame FROM multimedia_tab WHERE clip_id = 1"); if (rset.next()) { lob_loc1 = ((OracleResultSet)rset).getBLOB (1); } rset = stmt.executeQuery ( "SELECT frame FROM multimedia_tab WHERE clip_id = 99"); if (rset.next()) { lob_loc2 = ((OracleResultSet)rset).getBLOB (1); } if (lob_loc1.length() > lob_loc2.length()) System.out.println ("Looking for LOB2 inside LOB1. result = " + Long.toString(lob_loc1.position(lob_loc2, 1))); else System.out.println("Looking for LOB1 inside LOB2. result = " + Long.toString(lob_loc2.position(lob_loc1, 1))); stmt.close(); conn.commit(); conn.close(); } catch (SQLException e) { e.printStackTrace(); } } }
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