php - 使用用户函数从 mysql 返回结果

Question

请告诉，为什么这个代码是错误的？

function myres () {
   $db = new mysqli("localhost","userrr","pass","mvc");
   $res = $db->query("SELECT * FROM news ");
   return $res;
}


while ($row = myres()->fetch_row()) {
    echo  $row[0];
}

PS此代码正在运行：

$db = new mysqli("localhost","userrr","pass","mvc");
$res = $db->query("SELECT * FROM news ");
while ($row = $res->fetch_row()) {
    echo  $row[0];
}

Answer 1

你myres()每次都来这里，我想：

while ($row = myres()->fetch_row()) {
  echo  $row[0];
}

所以每次都$row包含结果的第一行，并且不会停止。我认为它会很好地工作：

$res = myres();

while ($row = $res->fetch_row()) {
  echo  $row[0];
}