php - MySQL Table Lock Issue -

i think might deadlock issue, i'm reading table data. or simple can't see.

my $msqli obj fine db access

but i'm bit stumped error.. being told clients table not being locked lock tables

any suggestions welcome.. here php code

$mysqli = $globals['mysqli']; $mysqli->query("lock tables clients read, invoices read, estimates read");  $mysqli->query("set @inv='invoice'"); $mysqli->query("set @est='estimate'");  $sql = " (select @inv, name client, invoices.id, invoices.ref ref, invoices.addts ts \n"         . "from `clients` , `invoices` \n"         . "where invoices.user_id =  " . $_session['user_id'] . " \n"         . "and clients.id = invoices.client_id)\n"         . "union all\n"         . "(select @est, name client, estimates.id, estimates.ref ref, estimates.addts ts \n"         . "from `clients` ,`estimates` \n"         . "where estimates.user_id =  " . $_session['user_id'] . " \n"         . "and clients.id = estimates.client_id) \n"         . "order ts desc limit 5";  if ($result = $mysqli->query($sql) or die(mysqli_error($mysqli))) { //do stuff here } 

when run $sql query in phpmyadmin successful... help..

********************solved (?) ******************

fixed (or seems be):

quote http://bugs.mysql.com/bug.php?id=6588

"you cannot use locked table multiple times in 1 query - use aliases that."

so query updated

    $mysqli->query("lock tables clients_t read,clients read ,                                 invoices read, estimates read"); $mysqli->query("set @inv='invoice'"); $mysqli->query("set @est='estimate'");  $sql = " " .         "(select @inv, name client, invoices.id,                    invoices.ref ref, invoices.addts ts "          . "from `clients` clients_t , `invoices`\n"         . "where invoices.user_id =  " . $_session['user_id'] . " \n"         . "and clients_t.id = invoices.client_id)\n"         . "union \n"         . "(select @est , name client, estimates.id,                     estimates.ref ref, estimates.addts ts\n"         . "from `clients` ,`estimates` \n"         . "where estimates.user_id =  " . $_session['user_id'] . "  \n"         . "and clients.id = estimates.client_id)\n"         . "order ts desc limit 5"; 

i needed lock alias table clients_t. anyway future users hope helps.

a little nit picky wise such addslashes or mysql_real_escape_string $_session['user_id'] input avoid injection issues.