将php数组转换为单个JSON对象

Question

在如何将php数组转换为JSON对象时，我遇到了问题。无论我如何尝试，我要么将所有内容打印为多个对象，要么将其作为null.Wrapping在pre tags中显示出来，下面是我得到的最接近的结果：

我的代码：

$content = mysqli_query($dbcon, 
  "SELECT title, last_name AS lastname
   FROM revision, field_last_name
   WHERE vid = entity_id;"
);

echo "<pre>";
while($row = mysqli_fetch_array($content))
{
  print json_encode($row);
  print '<br/>';
}
echo "</pre>";

我的产出：

{"0":"John Apple","title":"John Apple","1":"Apple","lastname":"Apple"}
{"0":"Kumar Patel","title":"Kumar Patel","1":"Patel","lastname":"Patel"}
{"0":"Michaela Quinn","title":"Michaela Quinn","1":"Quinn","lastname":"Quinn"}
{"0":"Peyton Manning","title":"Peyton Manning, MD","1":"Manning","lastname":"Manning"}
{"0":"John Doe","title":"John Doe","1":"Doe","lastname":"Doe"}
{"0":"Jane Lee","title":"Jane Lee","1":"Lee","lastname":"Lee"}
{"0":"Dan McMan","title":"Dan McMan","1":"McMan","lastname":"McMan"}
{"0":"Yu Win","title":"Yu Win","1":"Win","lastname":"Win"}

我的两个问题是：

1)为什么有一个"0":"John Apple"和一个"1":"Apple"，而我只想要对象中的"title":"John Apple"和"lastname":"Apple"？

2)为什么所有东西都以多个对象的形式显示？

谢谢!

--编辑--

$arr = array()

echo "<pre>";   

while($row = mysqli_fetch_assoc($content))
{     
  $arr[] = $row;
}

print $arr;
echo "</pre>";

Answer 1

field_last_name是您的表名吗？您能否根据查询中的revision.title这样的表名来区分每个列名前缀，然后在一个数组中获取所有数据，然后json_encode它呢？

   $content = mysqli_query($dbcon, 
      "SELECT title, last_name AS lastname
       FROM revision, field_last_name
       WHERE vid = entity_id;"
    );
    $arr = array();

    echo "<pre>";
    while($row = mysqli_fetch_assoc($content))
    {
      $arr[] = $row;
    }
      print_r(json_encode($arr));


    echo "</pre>";

Answer 2

改变这一点：

while($row = mysqli_fetch_array($content))
{
  print json_encode($row);
  print '<br/>';
}

对此：

$row = mysqli_fetch_assoc($content);
json_encode($row);

Answer 3

...because，您正在打印多个对象。如果您想要一个单独的对象，即数组，则需要将mysql_fetch_assoc的结果(请参阅涵盖字段名和位置的其他答案)附加到数组中，然后一次性地将数组添加到json_encode。示例：

$myarray = array();
while($row = mysqli_fetch_assoc($content))
{
  $myarray[] = $row;
  print '<br/>';
}
print json_encode($myarray);