我有一个音乐共享脚本，我正在尝试从我的 mysql 数据库创建 JSON，我正在尝试创建一个特定的结构，但似乎无法弄清楚
这是我的代码
<?php
//Create Database connection
$db = mysql_connect("localhost","UN","PW");
if (!$db) {
die('Could not connect to db: ' . mysql_error());
}
//Select the Database
mysql_select_db("DB",$db);
$result = mysql_query("SELECT * FROM users ORDER BY username ASC");
$json_response = array(); //Create an array
while ($row = mysql_fetch_array($result))
{
$row_array = array();
$row_array['idu'] = $row['idu'];
$row_array['username'] = $row['username'];
$row_array['first_name'] = $row['first_name'];
$row_array['last_name'] = $row['last_name'];
$row_array['country'] = $row['country'];
$row_array['image'] = $row['image'];
$row_array['cover'] = $row['cover'];
$row_array['description'] = $row['description'];
$row_array['playlists'] = array();
$row_array['tracks'] = array();
$plid = $row['idu'];
$option_qry = mysql_query("SELECT * FROM playlists where playlists.by=$plid");
while ($opt_fet = mysql_fetch_array($option_qry))
{
$row_array['playlists'][] = array(
'id' => $opt_fet['id'],
'name' => $opt_fet['name'],
'by' => $opt_fet['by'],
);
}
array_push($json_response, $row_array); //push the values in the array
//tracks
$option_qry = mysql_query("SELECT * FROM tracks where tracks.uid=$plid");
while ($opt_fet = mysql_fetch_array($option_qry))
{
$row_array['tracks'][] = array(
'id' => $opt_fet['id'],
'title' => $opt_fet['title'],
'name' => $opt_fet['name'],
'art' => $opt_fet['art'],
'likes' => $opt_fet['likes'],
'downloads' => $opt_fet['downloads'],
'plays' => $opt_fet['views'],
'uid' => $opt_fet['uid'],
);
}
array_push($json_response, $row_array); //push the values in the array
}
echo json_encode($json_response,JSON_PRETTY_PRINT);
?>
用户表:
id username last_name first_name country etc...
1 username1 Mynce George USA etc...
2 username2 Jenkins Fred USA etc...
3 username3 Walberg Mark USA etc...
4 username4 Smith Will USA etc...
播放列表表:
id by name
1 4 My playlists
2 3 Popular Songs
播放列表条目表:
id playlists track
12 1 13
13 1 23
14 1 3
15 1 17
16 1 9
12 2 14
13 2 24
14 2 4
15 2 18
16 2 10
轨道表:
id title name art likes downloads views
1 song_title song1.mp3 art1.png 13 8 55
2 song_title song2.mp3 art2.png 12 10 31
3 song_title song3.mp3 art3.png 7 32 50
4 song_title song4.mp3 art4.png 22 11 1
5 song_title song5.mp3 art5.png 1 28 2
下面的 JSON 是我想要获取的结构，我希望用户创建的每个播放列表都将与该播放列表关联的轨道嵌套在该播放列表 User>Playlists>Tracks 下的嵌套数组中( user>playlist1>t1,t2,t3,etc... & user>playlist2>t1,t2,t3,etc...)，(T 表示 Track fyi)
例如，我在这里输入了两个播放列表“We Give You Praise”和“We Give You Praise 2”
问题是这样的:我如何使用PLAYLISTENTRIES来排列/嵌套播放列表中的轨道？，我已经将 PLAYLISTS 嵌套在 USERS 下，但我不知道如何深入了解播放列表中的轨道
{
"idu": "2",
"username": "chicagochurch",
"first_name": "Chicago Christian Center",
"last_name": "",
"country": "United States",
"image": "839674815_146358938_1746691162.png",
"cover": "173157219_1187606488_302826016.jpg",
"description": "This is the official Chicago Church Music page.",
"playlists": [
{
"id": "4",
"name": "We Give You Praise",
"by": "2",
"tracks": [
{
"id": "29",
"title": "01 We Give You Praise",
"name": "1667450919_35711384_1898671201.mp3",
"art": "97020012_1272964020_1490042512.png",
"likes": "1",
"downloads": "1",
"plays": "4",
"uid": "2"
},
{
"id": "30",
"title": "02 Luvudees",
"name": "1361859314_884859216_209326964.mp3",
"art": "1591964284_1156840179_1721104535.png",
"likes": "0",
"downloads": "1",
"plays": "3",
"uid": "2"
},
{
"id": "31",
"title": "03 Mugo Del",
"name": "1366849477_130736941_1367659635.mp3",
"art": "1181156184_556035815_1698596436.png",
"likes": "0",
"downloads": "1",
"plays": "0",
"uid": "2"
},
{
"id": "32",
"title": "04 San Amensa",
"name": "40925819_971317614_1732715256.mp3",
"art": "837149755_251638008_1945445596.png",
"likes": "0",
"downloads": "0",
"plays": "1",
"uid": "2"
},
{
"id": "33",
"title": "05 One True God",
"name": "1201163785_1107025307_1077346045.mp3",
"art": "713651840_1636034922_1247445482.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "34",
"title": "06 Mugo Anav",
"name": "173569477_686122962_117960391.mp3",
"art": "1432749408_578109445_1094716795.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "35",
"title": "07 Hallelujah",
"name": "133051077_70993845_552471086.mp3",
"art": "2040610215_1811023913_383444282.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "36",
"title": "08 Sheppard",
"name": "984429058_1532916377_1375134853.mp3",
"art": "1153269141_143559426_997684622.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "37",
"title": "09 I Love you Lord",
"name": "794115968_1411878888_673035094.mp3",
"art": "1692460167_1433248811_682631716.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "38",
"title": "10 Jesus In The Center",
"name": "202390322_461558278_1271927584.mp3",
"art": "1048499380_362527600_4599069.png",
"likes": "0",
"downloads": "1",
"plays": "0",
"uid": "2"
},
{
"id": "39",
"title": "11 Mugo Luvudeemos",
"name": "274506373_302381815_356651583.mp3",
"art": "1229728795_739090349_686501748.png",
"likes": "0",
"downloads": "1",
"plays": "0",
"uid": "2"
},
{
"id": "40",
"title": "12 Onday Chedo Kud",
"name": "378498031_1470949688_1199351944.mp3",
"art": "308978665_1074723934_419931699.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "41",
"title": "13 The Word",
"name": "956461611_287666310_43661088.mp3",
"art": "1584112229_240532531_977129308.png",
"likes": "1",
"downloads": "4",
"plays": "0",
"uid": "2"
}
]
},
{
"id": "5",
"name": "We Give You Praise 2",
"by": "2",
"tracks": [
{
"id": "29",
"title": "01 We Give You Praise 2",
"name": "1667450919_35711384_1898671201.mp3",
"art": "97020012_1272964020_1490042512.png",
"likes": "1",
"downloads": "1",
"plays": "4",
"uid": "2"
},
{
"id": "30",
"title": "02 Luvudees 2",
"name": "1361859314_884859216_209326964.mp3",
"art": "1591964284_1156840179_1721104535.png",
"likes": "0",
"downloads": "1",
"plays": "3",
"uid": "2"
},
{
"id": "31",
"title": "03 Mugo Del 2",
"name": "1366849477_130736941_1367659635.mp3",
"art": "1181156184_556035815_1698596436.png",
"likes": "0",
"downloads": "1",
"plays": "0",
"uid": "2"
},
{
"id": "32",
"title": "04 San Amensa 2",
"name": "40925819_971317614_1732715256.mp3",
"art": "837149755_251638008_1945445596.png",
"likes": "0",
"downloads": "0",
"plays": "1",
"uid": "2"
},
{
"id": "33",
"title": "05 One True God",
"name": "1201163785_1107025307_1077346045.mp3",
"art": "713651840_1636034922_1247445482.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "34",
"title": "06 Mugo Anav 2",
"name": "173569477_686122962_117960391.mp3",
"art": "1432749408_578109445_1094716795.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "35",
"title": "07 Hallelujah 2",
"name": "133051077_70993845_552471086.mp3",
"art": "2040610215_1811023913_383444282.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "36",
"title": "08 Sheppard 2",
"name": "984429058_1532916377_1375134853.mp3",
"art": "1153269141_143559426_997684622.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "37",
"title": "09 I Love you Lord 2",
"name": "794115968_1411878888_673035094.mp3",
"art": "1692460167_1433248811_682631716.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "38",
"title": "10 Jesus In The Center 2",
"name": "202390322_461558278_1271927584.mp3",
"art": "1048499380_362527600_4599069.png",
"likes": "0",
"downloads": "1",
"plays": "0",
"uid": "2"
},
{
"id": "39",
"title": "11 Mugo Luvudeemos 2",
"name": "274506373_302381815_356651583.mp3",
"art": "1229728795_739090349_686501748.png",
"likes": "0",
"downloads": "1",
"plays": "0",
"uid": "2"
},
{
"id": "40",
"title": "12 Onday Chedo Kud 2",
"name": "378498031_1470949688_1199351944.mp3",
"art": "308978665_1074723934_419931699.png",
"likes": "0",
"downloads": "0",
"plays": "0",
"uid": "2"
},
{
"id": "41",
"title": "13 The Word 2",
"name": "956461611_287666310_43661088.mp3",
"art": "1584112229_240532531_977129308.png",
"likes": "1",
"downloads": "4",
"plays": "0",
"uid": "2"
}
]
}
]
}
正如您在上面的结构中看到的，播放列表在其自己的嵌套数组中列出了与其关联的轨道，我确信需要使用 playlistentries 表来实现此目的，但我不知道如何实现它，抱歉所有代码...但感谢您的帮助!
是否可以使用表“playlistsentries”执行此操作
播放列表 1(并列出播放列表的名称和信息)有轨道 1、2、3、4、5 等。并列出每个轨道的信息？并制作我想要实现的数据结构？
因为 playlistentries 似乎是将播放列表和轨道之间建立联系的表格...
我完全不知道该做什么......感谢您的帮助
最佳答案
一切都从您的查询开始。几乎任何时候您看到自己运行这样的嵌套查询，您都应该重新考虑您的方法。我建议使用联接在单个查询中查询所有数据，然后将该结果集读取到可以轻松序列化为 JSON 的数据结构中。
这是我将使用的查询:
SELECT
u.`idu` AS `user_id`,
u.`username` AS `user_name`,
u.`first_name` AS `first_name`,
u.`last_name` AS `last_name`,
u.`country` AS `user_country`,
u.`image` AS `user_image`,
u.`cover` AS `user_cover`,
u.`description` AS `user_description`,
pl.`id` AS `playlist_id`,
pl.`name` AS `playlist_name`,
t.`id` AS `track_id`,
t.`title` AS `track_title`,
t.`name` AS `track_name`,
t.`art` AS `track_art`,
t.`likes` AS `track_likes`,
t.`downloads` AS `track_downloads`,
t.`views` AS `track_plays`
FROM users AS u
INNER JOIN playlists AS pl
ON i.idu = pl.by
INNER JOIN playlistsentries AS ple
ON pl.id = ple.playlists
INNER JOIN tracks AS t
ON ple.track = t.id
ORDER BY `user_id` ASC, `playlist_id` ASC, `track_id` ASC
请注意，我使用别名字段来消除歧义，因此我们现在可以清楚地了解我们是否正在使用用户、播放列表或轨道级别字段。
获取结果集时，您一次迭代一个轨道。我们对结果集进行了排序，以便所有用户、播放列表和轨道都排序(分组)在一起，以便您可以查找当前行值的更改，以确定是否需要为用户和播放列表构建新的更高级别的数据容器。
实现编写所需数据结构并编码为 JSON 的示例代码如下所示:
// variable in which to store your results to be serialize
$result_array = array();
// some index and temp variables we will use to build the data structure
$current_user_id = 0;
$user_idx = -1;
$current_playlist_id = 0;
$playlist_idx = -1;
// Your database fetch logic here.
// I have not shown where actual query would be made.
// The query would obviously need to succeed before getting to this code.
// Note that you REALLY should be considering mysqli or PDO here
// instead of deprecated mysql extension.
while($row = /* your DB line fetch here - Consider using mysqli or PDO */) {
// is this a new user?
$user_id = (integer)$row['user_id'];
if($user_id !== $current_user_id) {
// manage our indexes
$current_user_id = $user_id;
$user_idx++;
$playlist_idx = -1;
// start a new object to store data for this user
$user_obj = new stdClass();
// set properties on user from current row
// name these properties whatever you want for final JSON structure
$user_obj->idu = $current_user_id;
$user_obj->username = $row['user_name'];
$user_obj->first_name = $row['first_name'];
$user_obj->last_name = $row['last_name'];
$user_obj->country = $row['user_country'];
$user_obj->image = $row['user_image'];
$user_obj->cover = $row['user_cover'];
$user_obj->description = $row['user_description'];
$user_obj->playlists = array();
// set object in overall result array
$result_array[$user_idx] = $user_obj;
}
// does this playlist already exist for this user?
$playlist_id = (int)$row['playlist_id'];
if($playlist_idx === -1 || $playlist_id !== $current_playlist_id ) {
// manage our indexes
$current_playlist_id = $playlist_id;
$playlist_idx++;
// start a new object to store data for this user
$playlist_obj = new stdClass();
// set properties on playlist from current row
// name these properties whatever you want for final JSON structure
$playlist_obj->id = $current_playlist_id;
$playlist_obj->name = $row['playlist_name'];
$playlist_obj->by = $current_user_id;
$playlist_obj->tracks = array();
// set object in overall result array
$result_array[$user_idx]->playlists[$playlist_idx] = $playlist_obj;
}
// create track object
// we do this for every row
$track_obj = new stdClass();
$track_obj->id = $row['track_id'];
$track_obj->title = $row['track_title'];
$track_obj->name = $row['track_name'];
$track_obj->art = $row['track_art'];
$track_obj->likes = $row['track_likes'];
$track_obj->downloads = $row['track_downloads'];
$track_obj->plays = $row['track_plays'];
$track_obj->uid = $current_user_id;
// set track object in result set
$result_array[$user_idx]->playlists[$playlist_idx]->tracks[] = $track_obj;
}
// serialize to JSON
$result_json = json_encode($result_array);
注意:我不太确定您为每个嵌套级别显示的各种用户 ID 值之间是否存在差异(如果有)。例如，如果轨道和/或播放列表的用户 ID 表示与当前用户不同的用户，则可能需要修改上面的代码。如果是这种情况，您需要将这些字段添加到查询中并将属性添加到对象中。
关于php - 如何从 MySql 将轨道排列到 PHP 中的播放列表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32319493/