Problem copying cusor, please check code.

Question

The function below is supposed to accept a database and a read cursor, and create a write cursor pointing to the the same record. It is supposed to work for databases with duplicate keys allowed (a requirement - although the combination of key and data is guaranteed to be unique.)
It doesnt work. the write cursor get function always returns DB_NOTFOUND and I cant figure out why.
thanks for any help you can give.
Steve
int DBUtil::createWriteCursor(Db* database, Dbc* readCursor, Dbc** writeCursor)
int result;
*writeCursor = NULL;
Dbt key;
Dbt data;
memset((void*) &key, 0, sizeof(Dbt));
memset((void*) &data, 0, sizeof(Dbt));
// first get the key and data from the current cursor, which represents a unique combination
result = readCursor->get(&key, &data, DB_CURRENT);
if (result != 0)
return result;
try
// open the writecursor
database->cursor(NULL, writeCursor, DB_WRITECURSOR);
catch(DbException ex)
return -1;
// move the cursor to the position in the database that matches the combo
result = (*writeCursor)->get(&key, &data, DB_GET_BOTH);
if (result != 0)
(*writeCursor)->close();
// will return 0 on success, or DB_NOTFOUND if some other error
return result;
p.s. if you have a better way to copy a cursor, that would be great!

Answer 1

Hello,
What platform and version is this? Are you using concurrent data store? You don't show how the readCursor was set up. Is it possible it does not refer to the same database as the writeCursor does? If you walk through the database and print out the key/data pairs, using DB_NEXT do you find the pair you are looking for? If you have a small stand-alone program that illustrates the behavior, you can also post that.
Thanks,
Sandra
Edited by: Oracle, Sandra Whitman on Feb 5, 2010 7:56 AM