php mysqli 受影响的行

Question

我只是在做一些测试，我不知道我这样做是否正确。查询会更新行。但是affected_rows总是返回0。为什么？

<?php 

$connection = new mysqli('localhost', 'user', 'pass', 'db');
if (mysqli_connect_errno()) {
   printf("Can't connect to MySQL Server. Errorcode: %s\n", mysqli_connect_error());
   exit;
}

$email      = $connection->real_escape_string($_GET['email']);
$activation = $connection->real_escape_string($_GET['hash']);

//$query =  $connection->query("SELECT email, activationCode, active FROM users WHERE email='".$email."' AND hash='".$activation."' AND active='0'");
$select = $connection->query("UPDATE users SET active = '1' WHERE email='".$email."' AND activationCode='".$activation."' AND active='0'");


printf("Affected rows (UPDATE): %d\n", $select->affected_rows);



$connection->close();
?>

Answer 1

上面写着$select->affected_rows，而不是$connection->affected_rows。

$select->affected_rows 包含有关有多少行受上次查询影响的信息（可能成功或不成功），而 connection 保存包含有关查询结果的数据的数据库管理器对象。