mysqli结果的数量取决于内部的提取

时间:2013-08-26 19:47:53

标签: php mysql mysqli

我从mysql表(作业)中获取行。在该获取内部,我也从另一个表(帐户)获取[接收帐户api密钥全部取决于ID_ASSOC对作业的影响]:下面是代码

$sql = "SELECT * FROM jobs";
$query = mysqli_query($db_conx, $sql);
while($row = mysqli_fetch_assoc($query)){
   echo $row['action'];
   echo "<br/>";
   $job_poster_id = $row['id_assoc'];

        $sql = "SELECT * FROM accounts WHERE id_assoc='$job_poster_id'";
        $query = mysqli_query($db_conx, $sql);
        while($rows = mysqli_fetch_assoc($query)){
        $username = $rows['twitter_username'];
            $consumer_key = $rows['consumer_key'];
            $consumer_secret = $rows['consumer_secret'];
            $access_token = $rows['access_token'];
            $access_token_secret = $rows['access_token_secret'];
        }

  echo $job_poster_id ;
  echo "<br/>";
  echo $twitter_username;
  echo "<br/>";
  echo "----------------------------------";
  echo "<br/>";
}

输出:

specific-message 
4 
admin
----------------------------------

当我这样做时,我只得到一行输出......我似乎无法找出原因。我希望上面的内容重复次数与行数相同,并且它只执行一行(在代码中使用帐户获取)。但是当我没有内部提取(帐户提取)时,它会根据需要返回多行。为什么是这样? (以下是没有提取帐户的示例代码):

$sql = "SELECT * FROM jobs";
$query = mysqli_query($db_conx, $sql);
while($row = mysqli_fetch_assoc($query)){
  echo $row['action'];
  echo "<br/>";
  $job_poster_id = $row['id_assoc'];

  echo $job_poster_id ;
  echo "<br/>";
  echo "----------------------------------";
  echo "<br/>";
} 

输出:

specific-message
4
----------------------------------
specific-message
1
----------------------------------
specific-message
2
----------------------------------

1 个答案:

答案 0 :(得分:1)

$query = mysqli_query($db_conx, $sql);
while($row = mysqli_fetch_assoc($query)){
    echo $row['action'];
    echo "<br/>";
    $job_poster_id = $row['id_assoc'];

    $sql = "SELECT * FROM accounts WHERE id_assoc='$job_poster_id'";
    $query = mysqli_query($db_conx, $sql);

问题在于您使用$query作为内部和外部查询。

当内部查询运行并且它遍历循环时,它会迭代到结果集的末尾;当外部while循环运行时,mysqli_fetch_assoc($query)返回false,因为您已经在结果集的末尾 - 而不是您期望的结果集。

您可以通过重命名其中一个$query变量来解决此问题。