爲什麼循環只執行一次？

Question

我有以下處理推文數據的小代碼。我期望我的循環迭代10次。但是，什麼情況是，它迭代一次，然後退出，沒有涉及到MySQL或其他任何錯誤的跡象。

$query = "select data from tweets where `screen_name` = 'username' limit 10"; 
$tweetsq = mysqli_query($mysqli, $query) or die(mysqli_error($mysqli)); 
$tweets = mysqli_fetch_assoc($tweetsq); 
$tweets_count = mysqli_num_rows($tweetsq); 
echo $tweets_count . '<br />'; //See output 

$count = 0; 
foreach ($tweets as $raw_tweet) { 
    $tweet = json_decode($raw_tweet); 
    $tweet_id = $tweet->id_str; 
    $is_reply = (isset($tweet->in_reply_to_screen_name) && strlen($tweet->in_reply_to_screen_name) > 0) ? 1 : 0; 
    $is_retweet = (isset($tweet->retweeted_status) && $tweet->retweeted_status != '') ? 1 : 0; 
    $entity_holder = array(); 
    $has_hashtag = $has_url = $has_mention = $has_media = 0; 
    foreach ($tweet->entities as $type => $entity) { 
     if (is_array($entity) && count($entity) < 1) { 
      //continue; 
     } else { 
      $entity = array_pop($entity); 
      switch ($type) { 
       case 'hashtags' : $has_hashtag = 1; break; 
       case 'urls' : $has_url = 1; break; 
       case 'user_mentions' : $has_mention = 1; break; 
       case 'media' : $has_media = 1; break; 
       default : 

      } 
     } 
    } 
    echo 'Updating recorde... <br />'; 
    $query = "UPDATE tweets SET is_reply='" . $is_reply . "' , is_retweet='" . $is_retweet . "', has_hashtag='" . $has_hashtag . "', has_url='" . $has_url . "', has_mention='" . $has_mention . "', has_media='" . $has_media . "' WHERE tweet_id='" . $tweet_id . "'"; 
    $result = mysqli_query($mysqli, $query) or die(mysqli_error($mysqli)); 
    var_dump($result); //See output 
    $count++; 
    echo '<br />'; 
} 
echo $count; 

輸出：

10 //This is the value of $tweets_count 
Updating recorde... 
bool(true) //The result of the UPDATE query 
1 //The value of $count at the end of script. It SHOULD be 10 

Answer 1

mysqli_fetch_assoc取單行作爲關聯數組，其中鍵是列名，值是該列的值。使用它的正確方法是遍歷結果集，直到獲取回報NULL，表明有沒有更多的行獲取：

while ($row = mysqli_fetch_assoc($tweetsq)) { 
    $raw_tweet = $row["data"]; 
    $tweet = json_decode($raw_tweet); 
    $tweet_id = $tweet->id_str; 
    # etc...