SQL_CONCUR_LOCK not supported ?

Hi again !

I am sorry that I have to bother you all with my porting problems
again.

In our backend we create special cursors for row locks like this
(works fine with MSSQL):

SQLAllocStmt(); // Create the cursor

SQLSetStmtAttr(SQL_ATTR_MAX_ROWS, 1); // The lock cursor only
delivers one row

SQLSetStmtAttr(SQL_ATTR_CURSOR_TYPE, SQL_CURSOR_FORWARD_ONLY);

SQLSetStmtAttr(SQL_ATTR_CONCURRENCY, SQL_CONCUR_LOCK); // Lock mode
that other cursor of this type will fail

// !!! Postgres changes this to SQL_CONCUR_ROWVER with "01S02
Requested value changed" !!!

SQLSetStmtAttr(SQL_ATTR_QUERY_TIMEOUT, 1); // Timeout to return when
a lock occours

SQLPrepare("SELECT col FROM table WHERE col = ? FOR UPDATE");

SQLBindCol();

SQLBindParameter();

SQLExecute(); // Lock the specified row and prevent that SELECT FOR
UPDATE from other users succeeds

// !!! Postgre brings here "01S02: cursor updatability changed"

Do I have to change the way to lock rows ?

I tested it with the actual PostgreSQL 9.2 and ODBC.

Big thanks in advance.

Regards

Johann