Re: UPDATE with data at exec and CURRENT OF question

Tom Lane schrieb:
> "lothar(dot)behrens(at)lollisoft(dot)de" <lothar(dot)behrens(at)lollisoft(dot)de> writes:
> > UPDATE "Kontakte" set "Notiz" = ? WHERE CURRENT OF SQL_CUR0x1321f670
>
> > Does PostgreSQL not support this syntax ?
>
> No.
>
> 8.3 will, FWIW.

So then I tried the following code, but I get SQLSTATE=01001 and not
the expected retval=SQL_NEED_DATA.

I tried to use SQL_FETCH_ABSOLUTE to the current cursor position, but
that seems not to help.

What's wrong ?

Thanks, Lothar

#define LB_BLOCKSIZE 10 // Forcing usage of SQLPutData

// hstmt is initialized
SQLRETURN rc, retcode;
SQLCHAR BinaryPtr[LB_BLOCKSIZE];
void* tempBuffer;
long remainingsize;
SQLINTEGER BinaryLenOrIndCurrentOf;
SQLINTEGER BinaryLenOrInd;

retcode = SQLAllocStmt(hdbc, &hupdatestmt); /* Statement handle */
retcode = SQLSetStmtOption(hupdatestmt, SQL_ATTR_CONCURRENCY,
SQL_CONCUR_ROWVER);
retcode = SQLSetStmtOption(hupdatestmt, SQL_CURSOR_TYPE,
SQL_CURSOR_KEYSET_DRIVEN);

value = "Hallo duda."; // 12 characters including 0

remainingsize = 12;
BinaryLenOrInd = 12;

BinaryLenOrIndCurrentOf = strlen("SQL_CURS0x012345678")+1;

rc = SQLBindCol(hstmt, column, SQL_C_BINARY, (void *)BinaryPtr, 0,
&BinaryLenOrIndCurrentOf);
memcpy(BinaryPtr, cursorname, BinaryLenOrIndCurrentOf);

retcode = SQLSetPos(hstmt, 1, SQL_UPDATE, SQL_LOCK_NO_CHANGE);
retcode = SQLBindCol(hstmt, column, SQL_C_BINARY, NULL, 0, 0);

// Force to reread current cursor data
retcode = SQLExtendedFetch(hstmt, SQL_FETCH_ABSOLUTE, pos,
&RowsFetched, &RowStat[0]);

tempBuffer = value;
BinaryLenOrInd = 12;
remainingsize = 12;

if (value->getSize() <= LB_BLOCKSIZE) {
memcpy(BinaryPtr, tempBuffer, value->getSize());
} else {
memcpy(BinaryPtr, tempBuffer, LB_BLOCKSIZE);
}

char* update_query = "UPDATE \"Kontakte\" SET \"Note\" = ? WHERE
\"Note\" LIKE 'SQL_CURS0x012345678%'";

retcode = SQLPrepare(hupdatestmt, update_query, SQL_NTS);

retcode = SQLBindParameter(hupdatestmt, 1, SQL_PARAM_INPUT,
SQL_C_BINARY, SQL_LONGVARBINARY,
0, 0, (SQLPOINTER) &BinaryPtr, 0, &BinaryLenOrInd);

retcode = SQLExecute(hupdatestmt);

long iteration = 0;

if ((retcode != SQL_SUCCESS) && (retcode != SQL_NEED_DATA)) {
printf("Execute query failed.\n"); // <<== Happens (SQLSTATE=01001)
}

if (retcode == SQL_NEED_DATA)
{
retcode = SQLParamData(hupdatestmt, (void **) &BinaryPtr);
while(retcode == SQL_NEED_DATA)
{
tempBuffer += LB_BLOCKSIZE;
remainingsize -= LB_BLOCKSIZE;

if (remainingsize <= LB_BLOCKSIZE) memcpy(BinaryPtr, tempBuffer,
remainingsize);
else memcpy(BinaryPtr, tempBuffer, LB_BLOCKSIZE);

retcode = SQLPutData(hupdatestmt, BinaryPtr, SQL_NTS);
retcode = SQLParamData(hupdatestmt, (void **) &BinaryPtr);
}
}

SQLFreeStmt(hupdatestmt, SQL_DROP);