MySQL in a Nutshell, 2nd Edition

Name

mysql_unbuffered_query()

Synopsis

resource mysql_unbuffered_query(sql_statement[, connection])

Use this function to execute an SQL statement given without buffering the results so that you can retrieve the data without having to wait for the results set to be completed. You may give an identifier as a second argument to interface with a different connection. The function returns false if the query is unsuccessful. For SQL statements that do not return a results set based on their nature (e.g., INSERT), the function returns true when successful. Use this function with care because an enormous results set could overwhelm the program’s allocated memory. Here is an example:

...
$sql_stmnt = "SELECT wrid, client_name, description
              FROM workreq, clients
              WHERE workreq.clientid = clients.clientid";
$results = mysql_unbuffered_query($sql_stmnt, $connection);
while($row = mysql_fetch_row($results)) {
  print "WR-$row[0]: $row[1] - $row[2] \n";
}
...

There’s no difference in the syntax of mysql_unbuffered_query() and mysql_query(), nor in the handling of the results. The only differences in this function are the speed for large databases and the fact that functions such as mysql_num_row() and mysql_data_seek() cannot be used, because the results set is not buffered and therefore cannot be analyzed by these functions.