如何合并两个表的数据并将其行扩展为数组？

Question

我想将两个表的数据合并 return 为 json，但我似乎做不对。我尝试了 INNER/LEFT 加入和嵌套查询，但都没有有效结果。

下面是我的表的结构：

事件：

----------------------------------
id |  title   | extra1 | extra2
----------------------------------
 1 | EventNo1 |  ...   |  ...
 2 | EventNo2 |  ...   |  ...
 3 | EventNo3 |  ...   |  ...
 4 | EventNo4 |  ...   |  ...
 5 | EventNo5 |  ...   |  ...

图片：

----------------------------------
id | event | val | height | width
----------------------------------
 2 |   5   | xxx |  xxx   |  xxx
 3 |   2   | xxy |  xxx   |  xxx
 6 |   5   | xyx |  xxx   |  xxx

所以基本上我想要的是从 events 获取数据，对于每个 images.event 匹配 events.id 的事件，我想用 images 的数据进行扩展.

这是我想要达到的 json 结果：

[
  {
    "id": "1",
    "title": "EventNo1",
    "extra1": "...",
    "extra2": "...",
    "images": []
  },
  {
    "id": "2",
    "title": "EventNo2",
    "extra1": "...",
    "extra2": "...",
    "images": [
      {
        "id": 3,
        "val": "xxy",
        "height": "xxx",
        "width": "xxx"
      }
    ]
  },
  {
    "id": "3",
    "title": "EventNo3",
    "extra1": "...",
    "extra2": "...",
    "images": []
  },
  {
    "id": "4",
    "title": "EventNo4",
    "images": []
  },
  {
    "id": "5",
    "title": "EventNo5",
    "extra1": "...",
    "extra2": "...",
    "images": [
      {
        "id": 2,
        "val": "xxx",
        "height": "xxx",
        "width": "xxx"
      },
      {
        "id": 6,
        "val": "xyx",
        "height": "xxx",
        "width": "xxx"
      }
    ]
  }
]

如何在 php + mysqli 中完成此操作？

Answer 1

伪代码，因为我不知道你用什么library/wrapper访问你的数据库：

$query = "select * from events";
$rows = $db->query($query);

foreach($rows as $k => $row) {
  $query = "select * from images where event = ".$row['id'];
  $rows[$k]['images'] = $db->query($query);
}

echo json_encode($rows);

这是假设 $db->query() returns 数组形式的结果集，如果找不到行则包括一个空数组。

Answer 2

$q = "select * from events";
$res = mysql_query($q);
while($row = mysql_fetch_assoc($res)){
 $image_data= array();
 $q2 = "select * from images where event = ".$row['id'];
 $res2 = mysql_query($q2);
 while($row2 = mysql_fetch_assoc($res2)){
 $image_data[] = $row2;
 }
 $row['images'] = $image_data;
 $event_data[] = $row;
}
echo json_encode($event_data);

如何合并两个表的数据并将其行扩展为数组？

How do I combine data of two tables and extend in it's row as array?

php

arrays

mysqli

inner-join

left-join