I want to insert a BLOB into MySQL via MyODBC.

The statement is like this:
UPDATE blob_table SET blob_col = ? WHERE blob_id = ?;
i bind the 1st column with indicator SQL_DATA_AT EXEC, the 2nd parameter (restriction) directly to a program variable.

i execute the statement (return value is as expected SQL_NEED_DATA).

i call SQLParamData to access the 1st parameter (return value is again SQL_NEED_DATA, as expected).

then i call several times SQLPutData, to insert the blob data (each with SQL_SUCCESS).

for finishing, i call again SQLParamData, but then the return value is not SQL_SUCCESS, as expected, but SQL_NEED_DATA.
the driver indicates, that it needs data also for the second parameter (restriction), which i bound directly to a program variable!

does anyone have an idea, how to solve this?