(PECL mysqlnd-uh >= 1.0.0-alpha)
MysqlndUhConnection::getFieldCount — Returns the number of columns for the most recent query
$connection
) : intReturns the number of columns for the most recent query.
connectionMysqlnd connection handle. Do not modify!
Number of columns.
MysqlndUhConnection::getFieldCount() is not only executed after the invocation of a user space API call which maps directly to it but also called internally.
Example #1 MysqlndUhConnection::getFieldCount() example
<?php
class proxy extends MysqlndUhConnection {
public function getFieldCount($res) {
printf("%s(%s)\n", __METHOD__, var_export(func_get_args(), true));
$ret = parent::getFieldCount($res);
printf("%s returns %s\n", __METHOD__, var_export($ret, true));
return $ret;
}
}
mysqlnd_uh_set_connection_proxy(new proxy());
$mysqli = new mysqli("localhost", "root", "", "test");
$mysqli->query("WILL_I_EVER_LEARN_SQL?");
var_dump($mysqli->field_count);
$mysqli->query("SELECT 1, 2, 3 FROM DUAL");
var_dump($mysqli->field_count);
?>
以上例程会输出：
proxy::getFieldCount(array ( 0 => NULL, )) proxy::getFieldCount returns 0 int(0) proxy::getFieldCount(array ( 0 => NULL, )) proxy::getFieldCount returns 3 proxy::getFieldCount(array ( 0 => NULL, )) proxy::getFieldCount returns 3 int(3)