Determining if a LOB Locator for a Temporary LOB Is Initialized

Figure 11-17 Use Case Diagram: Determining If a LOB Locator for a Temporary LOB Is Initialized

Text description of the illustration adl11tm5.gif

See: "Use Case Model: Internal Temporary LOBs", for all basic operations of Internal Temporary LOBs.

Purpose

This procedure describes how to see if a LOB locator for a temporary LOB is initialized.

Usage Notes

Not applicable.

Syntax

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

• PL/SQL (DBMS_LOB): There is no applicable syntax reference for this use case.

• C (OCI): Oracle Call Interface Programmer's Guide Chapter 15, "Relational Functions" -- LOB Functions, OCILobLocatorIsInit

• COBOL: A syntax reference is not applicable in this release.

• C/C++ (Pro*C/C++): Pro*C/C++ Precompiler Programmer's Guide Appendix F, "Embedded SQL Statements and Directives" -- LOB CREATE TEMPORARY. See also C(OCI) function, OCILobLocatorIsInit

• Visual Basic (OO4O): There is no applicable syntax reference for this use case.

• Java (JDBC): See Chapter 10, "Internal Persistent LOBs", "C (OCI): Checking If a LOB Locator Is Initialized" .

• Scenario

This generic function takes a LOB locator and checks if it is initialized. If it is initialized, then it prints out a message saying "LOB is initialized". Otherwise, it reports "LOB is not initialized".

Examples

Examples are provided in the following programmatic environments:

• PL/SQL (DBMS_LOB Package). No example is provided with this release.

• C (OCI): Determining If a LOB Locator for a Temporary LOB Is Initialized

• COBOL (Pro*Cobol): No example is provided with this release.

• C/C++ (Pro*C/C++): Determining If a LOB Locator for a Temporary LOB Is Initialized

• Visual Basic (OO4O): No example is provided with this release.

• Java (JDBC): No example is provided with this release.

C (OCI): Determining If a LOB Locator for a Temporary LOB Is Initialized

/* This function takes a LOB locator and checks if it is initialized. If it is

   initialized, then it prints out a message saying "LOB is initialized". 
   Otherwise, it says "LOB is not initialized". This function returns 
   0 if it completes successfully, and -1 if it doesn't. */

sb4 ck_isinit (OCILobLocator *lob_loc, 
               OCIError      *errhp,
               OCISvcCtx     *svchp,
               OCIStmt       *stmthp,
               OCIEnv        *envhp)
{
  boolean is_init;
  is_init= FALSE;
  if (OCILobLocatorIsInit(envhp,errhp, lob_loc, &is_init))
  {
    printf ("FAILED: OCILobLocatorIsInit call\n");
    return -1;
  }
  if(is_init)
  {
      printf ("LOB is initialized\n");
  }else
  {
      printf("LOB is not initialized\n");
   }
   return 0;
   }

C/C++ (Pro*C/C++): Determining If a LOB Locator for a Temporary LOB Is Initialized

This script is also located at $ORACLE_HOME/rdbms/demo/lobs/oci/tinitial

#include <sql2oci.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 tempLobLocatorIsInit_proc()
{
  OCIBlobLocator *Temp_loc;
  OCIEnv *oeh;
  OCIError *err;
  boolean isInitialized = 0;

  EXEC SQL WHENEVER SQLERROR DO Sample_Error();
  EXEC SQL ALLOCATE :Temp_loc;
  EXEC SQL LOB CREATE TEMPORARY :Temp_loc;
  /* Get the OCI Environment Handle using a SQLLIB Routine: */
  (void) SQLEnvGet(SQL_SINGLE_RCTX, &oeh);
  /* Allocate the OCI Error Handle: */
  (void) OCIHandleAlloc((dvoid *)oeh, (dvoid **)&err,
                        (ub4)OCI_HTYPE_ERROR, (ub4)0, (dvoid **)0);
  /* Use the OCI to determine if the locator is Initialized */
  (void) OCILobLocatorIsInit(oeh, err, Temp_loc, &isInitialized);
  if (isInitialized)
    printf("Locator is initialized\n");
  else
    printf("Locator is not initialized\n");
  /* Note that in this example, the locator is initialized. */
  /* Deallocate the OCI Error Handle: */
  (void) OCIHandleFree(err, OCI_HTYPE_ERROR);
  /* Free the Temporary LOB */
  EXEC SQL LOB FREE TEMPORARY :Temp_loc;
  /* Release resources held by the locator: */
  EXEC SQL FREE :Temp_loc;
}

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