mod_dbd and prepared statements (httpd-2.2.9)

[Andrej van der Zee]

Hi,

I am trying to use prepared INSERT statements for mod_dbd with the
mysql driver, but somehow always a 0 is written to the database
instead of a string. This is what I do:

// In configuration directives stage
ap_dbd_prepare(s, "INSERT INTO request_type (name) VALUES (%s) "
    "ON DUPLICATE KEY UPDATE frequency = frequency + 1", "insert_request_type");

// In hook post_read_request
apr_dbd_prepared_t *prep_stmt;
if (NULL == (prep_stmt = apr_hash_get(req_cfg->dbd->prepared,
"insert_request_type", APR_HASH_KEY_STRING))) {
  ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                 "DBD Log: Could not get prepared statement with label: 
insert_request_type");
  return DECLINED;
}

int nrows, rv;
if (rv = apr_dbd_pvquery(req_cfg->dbd->driver, r->pool,
req_cfg->dbd->handle, &nrows, prep_stmt, req_cfg->request_type, NULL))
{
   ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
                 "DBD Log: Failed to execute prepared statement with label:
insert_request_type");
   return DECLINED;
}

Then this is what ends up in my MySQL log:

Prepare INSERT INTO request_type (name) VALUES (?) ON DUPLICATE KEY
UPDATE frequency = frequency + 1
Execute INSERT INTO request_type (name) VALUES (0) ON DUPLICATE KEY
UPDATE frequency = frequency + 1

So it seems that the statement is prepared correctly, but somehow the
string I want to write is replaced by a 0. Am I doing something
terribly wrong here? I don't get it.

Cheers,
Andrej