所以我有这个架构，如image。
所示现在，虽然我一直想弄清楚如何做到这一点，但我得说我没有变得有点聪明......
我想知道的是，是否可以从一个查询中获得这样的结果？
{
"activitys": [
{
"activity_name": "Bicycling",
"attributes": [
{
"attribute_name": "Time"
},
{
"attribute_name": "city",
"options": [
{
"option_name": "Stockholm"
},
{
"option_name": "Vasteras"
}
]
}
]
},
{
"activity_name":"asdf"
...and so on
}
]
}
如果是这样，我该怎么办？
此外，我的架构看起来很愚蠢还是有一些逻辑呢？ 我现在还是新手，我觉得我可能有过于复杂或误解的东西......
先谢谢
编辑：经过多次填充后，我现在设法获取彼此相关的数据，如下所示：
{
"success": 1,
"activitys": [
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": "47",
"attribute_name": "City",
"option_id": "50",
"option_name": "Stockholm"
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": "47",
"attribute_name": "City",
"option_id": "51",
"option_name": "Vasteras"
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": null,
"attribute_name": "Duration",
"option_id": null,
"option_name": null
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": "49",
"attribute_name": "Bike",
"option_id": "52",
"option_name": "Grandmas old bike"
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": "49",
"attribute_name": "Bike",
"option_id": "53",
"option_name": "My superfast bike"
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": "49",
"attribute_name": "Bike",
"option_id": "54",
"option_name": "My childhood bike"
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": "49",
"attribute_name": "Bike",
"option_id": "55",
"option_name": "Pablos bike"
},
{
"activity_id": "16",
"activity_name": "Bicycling",
"attribute_id": null,
"attribute_name": "Distance",
"option_id": null,
"option_name": null
},
{
"activity_id": "17",
"activity_name": "Running",
"attribute_id": null,
"attribute_name": "Duration",
"option_id": null,
"option_name": null
}
]
}
但是正如您所看到的，由于某种原因，那些没有任何选项的属性的attribute_id没有出现.. 我想当我对其进行排序时，我只需要提出一些算法来按预期格式化我的响应（作为我原始帖子中的JSON字符串），因为使用mysqli返回的行似乎无法实现。
这是我的代码：
if (isset($_POST['get_activitys'])) {
$records = array();
$sql = "SELECT *
FROM activities a
LEFT JOIN activity_attributes aa ON a.activity_id = aa.activity_id
LEFT JOIN attributes at ON aa.attribute_id = at.attribute_id
LEFT JOIN attributes_options ao ON at.attribute_id = ao.attribute_id
LEFT JOIN options o ON ao.option_id = o.option_id";
if($results = $conn->query($sql)) {
if ($results->num_rows) {
while ($row = $results->fetch_object()) {
$records[] = $row;
}
$results->free();
if (!count($records)) {
$response['success'] = 0;
$response['message'] = "Hittade inga aktiviteter";
die(json_encode($response));
} else {
$response['success'] = 1;
$response['activitys'] = array();
foreach ($records as $r) {
array_push($response['activitys'], $r);
}
// Testing
echo "<pre>";
echo json_encode($response, JSON_PRETTY_PRINT);
echo "</pre>";
die();
die(json_encode($response));
}
} else {
$response['success'] = 0;
$response['message'] = "Hittade inga aktiviteter";
die(json_encode($response));
}
} else {
$response['success'] = 0;
$response['message'] = "Database query failed: (" . $conn->errno . ") " . $conn->error;
die(json_encode($response));
}
}
答案 0 :(得分：0)
您的查询没问题。您需要在嵌套数组中构造查询结果。这是未经测试的代码。
if (isset($_POST['get_activitys'])) {
$records = array();
$activity_names = array();
$attribute_names = array();
$sql = "SELECT *
FROM activities a
LEFT JOIN activity_attributes aa ON a.activity_id = aa.activity_id
LEFT JOIN attributes at ON aa.attribute_id = at.attribute_id
LEFT JOIN attributes_options ao ON at.attribute_id = ao.attribute_id
LEFT JOIN options o ON ao.option_id = o.option_id";
if($results = $conn->query($sql)) {
if ($results->num_rows) {
while ($row = $results->fetch_object()) {
$activity_names[$row->activity_id] = $row->activity_name;
$attribute_names[$row->attribute_id] = $row->attribute_name;
$records[$row->activity_id][$row->attribute_id][$row->option_id] = $row->option_name;
}
$results->free();
if (!count($records)) {
$response['success'] = 0;
$response['message'] = "Hittade inga aktiviteter";
die(json_encode($response));
} else {
$response['success'] = 1;
$response['activitys'] = array();
foreach ($records as $activity_id => $activity) {
$activity_obj = array('activity_name' => $activity_names[$activity_id], 'attributes' => array());
foreach ($activity as $attribute_id => $attributes) {
$attribute_obj = array('attribute_name' => attribute_names[$attribute_id], 'options' => array());
foreach ($attributes as $option_id => $option_name) {
$option_obj = array('option_name' => $option_name);
$attribute_obj['options'][] = $option_obj;
}
if (!count($attribute_obj['options'])) {
unset($attribute_obj['options']);
}
$activity_obj['attributes'][] = $attribute_obj;
}
if (!count($activity_obj['attributes'])) {
unset($activity_obj['attributes']);
}
$response['activitys'][] = $activity_obj;
}
// Testing
echo "<pre>";
echo json_encode($response, JSON_PRETTY_PRINT);
echo "</pre>";
die();
die(json_encode($response));
}
} else {
$response['success'] = 0;
$response['message'] = "Hittade inga aktiviteter";
die(json_encode($response));
}
} else {
$response['success'] = 0;
$response['message'] = "Database query failed: (" . $conn->errno . ") " . $conn->error;
die(json_encode($response));
}
}