Php MySQLi查询以使用纯关系表连接多个表

所以我有这个模式，如图所示

现在，当我一整天都在想如何做到这一点的时候，我得说我一点也没变聪明

我想知道的是，是否有可能从一个查询中得到这样的结果

    {
      "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，我该怎么做

此外，我的模式看起来愚蠢吗，还是有一些逻辑？ 我在这方面还是个新手，我觉得我可能把事情搞得过于复杂或是曲解了

提前谢谢

编辑：在进行了更多的FIDDELL操作之后，我现在已经成功地获得了相互关联的数据，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，由于某些原因，那些没有任何选项的属性的属性_id没有出现。。 我想，当我整理好这些之后，我只需要想出一些算法，以便按照预期格式化我的响应（如我的原始帖子中的JSON字符串），因为这似乎不可能用mysqli返回的行实现

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));
        }
    }

if（isset（$\u POST['get\u activitys']））{
$records=array（）；
$sql=“选择*
来自活动a
左连接a.activity\u id=aa.activity\u id上的活动属性aa
aa.attribute\u id=at.attribute\u id上的左连接属性
at.attribute\u id=ao.attribute\u id上的左连接属性\u选项ao
ao上的左连接选项o.option_id=o.option_id”；
如果（$results=$conn->query（$sql））{
如果（$results->num\u行）{
而（$row=$results->fetch_object（））{
$records[]=$row；
}
$results->free（）；
如果（！计数（$records））{
$response['success']=0；
$response['message']=“Hittade inga Aktiviter”；
die（json_编码（$response））；
}否则{
$response['success']=1；
$response['activitys']=array（）；
foreach（$记录为$r）{
数组推送（$response['activitys'，$r）；
}
//测试
回声“；
if (isset($_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));
    }
}

echo json_encode（$response，json_PRETTY_PRINT）；
if (isset($_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));
    }
}

回声“；
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));
    }
}

模具（）；
die（json_编码（$response））；
}           
}否则{
$response['success']=0；
$response['message']=“Hittade inga Aktiviter”；
die（json_编码（$response））；
}
}否则{
$response['success']=0；
$response['message']=“数据库查询失败：（“$conn->errno.””）“$conn->error；
die（json_编码（$response））；
}
}

您的查询没有问题。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（$\u POST['get\u activitys']））{
$records=array（）；
$activity_names=array（）；
$attribute_names=array（）；
$sql=“选择*
来自活动a
左连接a.activity\u id=aa.activity\u id上的活动属性aa
aa.attribute\u id=at.attribute\u id上的左连接属性
at.attribute\u id=ao.attribute\u id上的左连接属性\u选项ao
ao上的左连接选项o.option_id=o.option_id”；
如果（$results=$conn->query（$sql））{
如果（$results->num\u行）{
而（$row=$results->fetch_object（））{
$activity\u name[$row->activity\u id]=$row->activity\u name；
$attribute\u names[$row->attribute\u id]=$row->attribute\u name；
$records[$row->activity\u id][$row->attribute\u id][$row->option\u id]=$row->option\u name；
}
$results->free（）；
如果（！计数（$records））{
$response['success']=0；
$response['message']=“Hittade inga Aktiviter”；
die（json_编码（$response））；
}否则{
$response['success']=1；
$response['activitys']=array（）；
foreach（$activity\u id=>$activity记录）{
$activity\u obj=array（'activity\u name'=>$activity\u names[$activity\u id]，'attributes'=>array（））；
foreach（$activity作为$attribute\u id=>$attributes）{
$attribute\u obj=array（'attribute\u name'=>attribute\u names[$attribute\u id]，'options'=>array（））；
foreach（$option\u id=>$option\u name的属性）{
$option\u obj=array（'option\u name'=>$option\u name）；
$attribute_obj['options'][=$option_obj；
}
如果（！count（$attribute_obj['options']））{
未设置（$attribute_obj['options']）；
}
$activity_obj['attributes'][=$attribute_obj；
}
如果（！count（$activity_obj['attributes']））{
未设置（$activity_obj['attributes'）；
}
$response['activitys'][]=$activity\u obj；
}
//测试
回声“；
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));
    }
}

echo json_encode（$response，json_PRETTY_PRINT）；
if (isset($_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));
    }
}

回声“；
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));
    }
}

模具（）；
die（json_编码（$response））；
}           
}否则{
$response['success']=0；
$response['message']=“Hittade inga Aktiviter”；
die（json_编码（$response））；
}
}否则{
$response['success']=0；
$response['message']=“数据库查询失败：（“$conn->errno.””）“$conn->error；
die（json_编码（$response））；
}
}

关键问题：你尝试了什么？@tadman我尝试了基于