Mysqli data cacheing, of sorts

Not sure if relevant, but, just wondering...

Either way, busy with a largeish data capture webpage, and to try a bit of testing, am trying to wipe out any prior data entered higher up in page, using something like the following:
$mysqliObj->query("delete from tbl_table_name;");

and, then lower down, when I run something similar to the following, it does still seem to retrieve the prior data:
$res = $mysqliObj->query("select * from tbl_table_name;");

Do I need to set a specific mysqli/mysql option, or do something like close and re-open the connection to have my prior delete, or insert/update queries taken note of?

And, asking this since am pretty sure I remember something like this being necessary, but, can't remember enough details, or find anything obviously relevant via google searches, etc.?

TIA

Jacob Kruger
Blind Biker
Skype: BlindZA
'...fate had broken his body, but not his spirit...'