Release 2 (8.1.6)
A76940-01
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| Oracle8i Application Developer's Guide - Large Objects (LOBs) Release 2 (8.1.6) A76940-01 |
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External LOBs (BFILEs), 29 of 41
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See Also:
"Use Case Model: External LOBs (BFILEs)" for all basic operations of External LOBs (BFILES). |
This procedure describes how to copy a LOB locator for a BFILE.
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:
This example assigns one BFILE locator to another related to Photo.
The examples are provided in the following five programmatic environments:
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Note: Assigning one BFILE to another using PL/SQL entails using the "=" sign. This is discussed in more detail with regard to "Read-Consistent Locators" in Chapter 5, "Advanced Topics". |
/* Note that the example procedure BFILEAssign_proc is not part of the DBMS_LOB package: */ CREATE OR REPLACE PROCEDURE BFILEAssign_proc IS Lob_loc1 BFILE; Lob_loc2 BFILE; BEGIN SELECT Photo INTO Lob_loc1 FROM Multimedia_tab WHERE Clip_ID = 3 FOR UPDATE; /* Assign Lob_loc1 to Lob_loc2 so that they both refer to the same operating system file: */ Lob_loc2 := Lob_loc1; /* Now you can read the bfile from either Lob_loc1 or Lob_loc2. */ END;
/* Select the lob/bfile from the Multimedia table */ void selectLob(Lob_loc, errhp, svchp, stmthp) OCILobLocator *Lob_loc; OCIError *errhp; OCISvcCtx *svchp; OCIStmt *stmthp; { OCIDefine *dfnhp; text *selstmt = (text *) "SELECT Photo FROM Multimedia_tab \ WHERE Clip_ID = 3"; /* Prepare the SQL select statement */ checkerr (errhp, OCIStmtPrepare(stmthp, errhp, selstmt, (ub4) strlen((char *) selstmt), (ub4) OCI_NTV_SYNTAX, (ub4)OCI_DEFAULT)); /* Call define for the bfile column */ checkerr (errhp, OCIDefineByPos(stmthp, &dfnhp, errhp, 1, (dvoid *)&Lob_loc, 0 , SQLT_BFILE, (dvoid *)0, (ub2 *)0, (ub2 *)0, OCI_DEFAULT)); /* Execute the SQL select statement */ checkerr (errhp, OCIStmtExecute(svchp, stmthp, errhp, (ub4) 1, (ub4) 0, (CONST OCISnapshot*) 0, (OCISnapshot*) 0, (ub4) OCI_DEFAULT)); } void BfileAssign(envhp, errhp, svchp, stmthp) OCIEnv *envhp; OCIError *errhp; OCISvcCtx *svchp; OCIStmt *stmthp; { OCILobLocator *src_loc; OCILobLocator *dest_loc; /* Allocate the locator descriptors */ (void) OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &src_loc, (ub4) OCI_DTYPE_FILE, (size_t) 0, (dvoid **) 0); (void) OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &dest_loc, (ub4) OCI_DTYPE_FILE, (size_t) 0, (dvoid **) 0); /* Select the bfile */ selectLob(src_loc, errhp, svchp, stmthp); checkerr(errhp, OCILobLocatorAssign(svchp, errhp, src_loc, &dest_loc)); /* Free the locator descriptor */ OCIDescriptorFree((dvoid *)src_loc, (ub4)OCI_DTYPE_FILE); OCIDescriptorFree((dvoid *)dest_loc, (ub4)OCI_DTYPE_FILE); }
IDENTIFICATION DIVISION. PROGRAM-ID. BFILE-COPY-LOCATOR. ENVIRONMENT DIVISION. DATA DIVISION. WORKING-STORAGE SECTION. 01 USERID PIC X(11) VALUES "SAMP/SAMP". 01 BFILE1 SQL-BFILE. 01 BFILE2 SQL-BFILE. 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. BILFE-COPY-LOCATOR. EXEC SQL WHENEVER SQLERROR DO PERFORM SQL-ERROR END-EXEC. EXEC SQL CONNECT :USERID END-EXEC. * Allocate and initialize the BFILE locator: EXEC SQL ALLOCATE :BFILE1 END-EXEC. EXEC SQL ALLOCATE :BFILE2 END-EXEC. EXEC SQL WHENEVER NOT FOUND GOTO END-OF-BFILE END-EXEC. EXEC SQL SELECT PHOTO INTO :BFILE1 FROM MULTIMEDIA_TAB WHERE CLIP_ID = 3 END-EXEC. EXEC SQLLOB ASSIGN :BFILE1 TO :BFILE2 END-EXEC. END-OF-BFILE. EXEC SQL WHENEVER NOT FOUND CONTINUE END-EXEC. EXEC SQL FREE :BFILE1 END-EXEC. EXEC SQL FREE :BFILE2 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.
#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 BFILEAssign_proc() { OCIBFileLocator *Lob_loc1, *Lob_loc2; EXEC SQL WHENEVER SQLERROR DO Sample_Error(); EXEC SQL ALLOCATE :Lob_loc1; EXEC SQL ALLOCATE :Lob_loc2; EXEC SQL SELECT Photo INTO :Lob_loc1 FROM Multimedia_tab WHERE Clip_ID = 3; /* Assign Lob_loc1 to Lob_loc2 so that they both refer to the same operating system file: */ EXEC SQL LOB ASSIGN :Lob_loc1 TO :Lob_loc2; /* Now you can read the BFILE from either Lob_loc1 or Lob_loc2 */ } void main() { char *samp = "samp/samp"; EXEC SQL CONNECT :samp; BFILEAssign_proc(); EXEC SQL ROLLBACK WORK RELEASE;}
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 Ex4_81 { 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 { BFILE lob_loc1 = null; BFILE lob_loc2 = null; ResultSet rset = stmt.executeQuery ( "SELECT photo FROM multimedia_tab WHERE clip_id = 3"); if (rset.next()) { lob_loc1 = ((OracleResultSet)rset).getBFILE (1); } // Assign lob_loc1 to lob_loc2 so that they both refer // to the same operating system file. // Now the BFILE can be read through either of the locators: lob_loc2 = lob_loc1; stmt.close(); conn.commit(); conn.close(); } //catch (SQLException e) catch (Exception e) { e.printStackTrace(); } } }
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