Handling DB query errors

I am not sure about how to properly handle DB Query errors.  Here is a
typical query where the possible is NOT handled.  Any suggestions are
welcomed e.g. how to code the query; how to have an error page; how to
handle errors produced by the Interbase server.

/* Get member data */
function db_get_member_data($dbh, $member_id) {
$stmnt = "SELECT * FROM Member WHERE MEM_MEM_ID='" . $member_id . "'";
$sthdl = ibase_query($stmnt,$dbh);
return $sthdl;
}

Todd
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