我目前有一个名为beacon_logs的文档,每当我走进一个信标范围时它就会记录。数据看起来类似于:
{
"_id": "00198cd8f0fc510dbad06bf24e93f55b",
"_rev": "1-e90f025935847b0412923e4ba472cf2a",
"device": "gwen",
"beaconUUID": "123",
"distance": "0.0",
"timestamp": 1487443924
},
{
"_id": "00198cd8f0fc510dbad06bf24e93f55c",
"_rev": "1-e90f025935847b0412923e4ba472cf2a",
"device": "gwen",
"beaconUUID": "123",
"distance": "0.1",
"timestamp": 1487443925
},
{
"_id": "01ab15fd3a1c7c37ba147be8c56fe389",
"_rev": "1-587035fb7a71962c21f91b86aca56a77",
"device": "gwen",
"beaconUUID": "456",
"distance": "0.87",
"timestamp": 1487031602
},
{
"_id": "01ab15fd3a1c7c37ba147be8c56fe388",
"_rev": "1-587035fb7a71962c21f91b86aca56a77",
"device": "gwen",
"beaconUUID": "456",
"distance": "0.87",
"timestamp": 1487031603
}
这个观点:
function (doc) {
emit([doc.beaconUUID,doc.timestamp], doc);
}
我想要的是获得所有特定的beaconuuid(即123)并让它按时间戳排序。这是我写的查询:
*DB_NAME*/_design/*DDOC_NAME*/_view/*VIEW_NAME*?descending=false&startkey=["123",999999999]&endkey=["123",0]
然而,这会给我带来非常随机的结果,包括其他beaconUUID。
我对这个冗长的解释的问题是:假设密钥是一个数组,有没有办法查询数组中的1个值,例如
*DB_NAME*/_design/*DDOC_NAME*/_view/*VIEW_NAME*?descending=false&key[0]="123"
如果没有,是否有人能推荐一个解决方法?
答案 0 :(得分:1)
使用此视图
function (doc) {
if (doc.beaconUUID) {
emit([doc.beaconUUID,doc.timestamp], doc);
}
}
我能够通过这些查询获得正确的答案:
按时间顺序排列的时间戳顺序:
*DB_NAME*/_design/*DDOC_NAME*/_view/*VIEW_NAME*?startkey=["123",0]&endkey=["123",{}]
反向时间顺序时间戳顺序:
*DB_NAME*/_design/*DDOC_NAME*/_view/*VIEW_NAME*?startkey=["123",{}]&endkey=["123",0]&descending=true
答案 1 :(得分:0)
您是否考虑过使用Cloudant query?
定义索引
POST /$DATABASE/_index HTTP/1.1
{
"index": {
"fields": [
"beaconUUID",
"timestamp"
]
},
"type": "json"
}
...并查询
POST /$DATABASE/_find HTTP/1.1
在BODY中传递查询
{
"selector": {
"beaconUUID": {
"$eq": "123"
}
},
"sort": [
"beaconUUID",
"timestamp"
]
}
P.S。如果您想知道为什么beaconUUID
包含在排序定义中,请参阅Cloudant: How to create an index for "Sort" function?
答案 2 :(得分:0)
对于其他寻找此问题替代方案的人,以下是关于_find的发现。
_find query
{
'selector': {
'beaconUUID':'123'
},
'fields': ['beaconUUID', 'timestamp'],
'sort': [
{'beaconUUID':'desc'},
{'timestamp':'desc'}
]
}
使用_find
通过PHP CURL
$url = 'https://'.<ACCOUNTNAME>.'.cloudant.com/<DB_NAME>/_find';
$fields = array(
'selector' => array('beaconUUID'=>"123"),
'fields' => array("beaconUUID",
"timestamp"),
'sort' => array(array("beaconUUID"=>"desc"),
array("timestamp"=>"desc"))
);
$fields_string = json_encode($fields);
$ch = curl_init();
curl_setopt($ch,CURLOPT_URL,$url);
curl_setopt($ch, CURLOPT_USERPWD, <APIKEY> . ":" . <APIPASSWORD>);
curl_setopt($ch,CURLOPT_RETURNTRANSFER,true);
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields_string);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-type: application/json',
'Accept: */*'
));
$output=curl_exec($ch);
curl_close($ch);
echo $output;
通过PHP-On-Couch
require_once 'PHP-on-Couch/Couch.php';
require_once 'PHP-on-Couch/CouchAdmin.php';
require_once 'PHP-on-Couch/CouchClient.php';
require_once 'PHP-on-Couch/CouchDocument.php';
require_once 'PHP-on-Couch/CouchReplicator.php';
require_once 'PHP-on-Couch/Exceptions/CouchException.php';
require_once 'PHP-on-Couch/Exceptions/CouchConflictException.php';
require_once 'PHP-on-Couch/Exceptions/CouchExpectationException.php';
require_once 'PHP-on-Couch/Exceptions/CouchForbiddenException.php';
require_once 'PHP-on-Couch/Exceptions/CouchNoResponseException.php';
require_once 'PHP-on-Couch/Exceptions/CouchNotFoundException.php';
require_once 'PHP-on-Couch/Exceptions/CouchUnauthorizedException.php';
use PHPOnCouch\Couch,
PHPOnCouch\CouchAdmin,
PHPOnCouch\CouchClient;
$fullurl = 'http://'.<APIKEY>.':'.<APIPASSWORD>.'@'.<ACCOUNTNAME>.'.cloudant.com';
$client = new CouchClient($fullurl,$DATABASE);
$sort = [
["beaconUUID" => 'desc'],
["timestamp" => 'desc']
];
$fields = ['beaconUUID', 'timestamp'];
$find = ['beaconUUID'=>"123"];
$docs = $client->skip(10)->limit(30)->sort($sort)->fields($fields)->find($find);
echo json_encode($docs);