Re: Newbie question regarding LOB

From: Dave Hau <davehau-no-spam-123_at_no-spam.netscape.net>
Date: Tue, 11 Nov 2003 09:48:32 GMT
Message-ID: <Qf2sb.14$2G4.10@newssvr22.news.prodigy.com>

First you do a "select for update" to get the lob locator and lock the row. Then you open the lob using OCILobOpen(), write into the lob using OCILobWrite(), and then close the lob using OCILobClose(). Here's some sample code:

void writeDataToLob(envhp, errhp, svchp, stmthp)

OCIEnv    *envhp;
OCIError  *errhp;
OCISvcCtx *svchp;
OCIStmt   *stmthp;

{
  OCILobLocator *lob_ptr;
  unsigned int amt = MAXSIZE; /* assume you want to write all MAXSIZE bytes */
  char buff[MAXSIZE];
  sb4 err;

  (void) OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &lob_ptr,

                            (ub4)OCI_DTYPE_LOB, (size_t) 0, (dvoid **) 0);

  text *sqlstmt =
    (text *) "SELECT lob_column FROM mytable \

                WHERE id = 1 FOR UPDATE";

  OCIDefine *defnp1;
  checkerr (errhp, OCIStmtPrepare(stmthp, errhp, sqlstmt,

(ub4)strlen((char *)sqlstmt),
(ub4) OCI_NTV_SYNTAX, (ub4) OCI_DEFAULT));
  checkerr (errhp, OCIDefineByPos(stmthp, &defnp1, errhp, (ub4) 1,

(dvoid *) &lob_ptr, (sb4)0,
(ub2) SQLT_CLOB,(dvoid *) 0,
(ub2 *) 0, (ub2 *) 0, (ub4) OCI_DEFAULT));
 /* Execute the select and fetch one row */   checkerr(errhp, OCIStmtExecute(svchp, stmthp, errhp, (ub4) 1, (ub4) 0,

                                 (CONST OCISnapshot*) 0, (OCISnapshot*) 0,
                                 (ub4) OCI_DEFAULT));

  checkerr (errhp, (OCILobOpen(svchp, errhp, lob_ptr, OCI_LOB_READWRITE)));

  checkerr (errhp, OCILobWrite (svchp, errhp, lob_ptr, &amt,

(ub4) 1, buff, MAXSIZE,

                                  OCI_ONE_PIECE, (dvoid *)0,


                                  (sb4 (*)(dvoid*,dvoid*,ub4*,ub1 *))0,

                                  0, SQLCS_IMPLICIT));

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

  (void) OCIDescriptorFree((dvoid *) lob_ptr, (ub4) OCI_DTYPE_LOB);

  return;
}

For more details, see

http://download-west.oracle.com/docs/cd/B10501_01/appdev.920/a96591/adl10pst.htm#1759678

HTH,
Dave

"Shankar" <shanky191_at_rediffmail.com> wrote in message news:24707dc9.0311101903.3ded3065_at_posting.google.com...

> I intend to write a BLOB to database by binding a variable of type
> OCILobLocator through OCIBindByName and then OCIExecuteStmt....I get
> this data from another module as a character array. How do i copy the
> contents of the array into my OCILobLocator?
>
> char buff[MAXSIZE]; ---> contains the data i wish to write (MAXSIZE is
> HUGE!)
> OCILobLocator *lob_ptr;
>
> Now to copy buff to lob_ptr????

Received on Tue Nov 11 2003 - 03:48:32 CST