Checking consecutive values at a MySQL query -


i have mysql table this:

id - time - value

and i'm getting every pair of id, time (grouped id) value greater threshold. basicaly, i'm getting every id has @ least 1 time value greater threshold. query looks this:

select id, time mydb.mytable value>%s , time>=%s , time<=%s group id

edit: time checks allow operate in time range of choice between data table; has nothing else asking.

it works perfectly, want add filtering: want avoid times value greater threshold (let's call alarms) if alarm hasn't happened time before or after. mean: if alarm accurs @ single, isolated instant of time instead of 2 consecutive instants of time, i'll consider false alarm , avoid returned @ query response.

of course can call each id check this, i'd in single query make faster. guess use conditionals, don't have expertise @ mysql.

any help?

edit2: example threshold = 10

id - time - value 1  - 2004 -   9 1  - 2005 -  11 1  - 2006 -   8 2  - 2107 -  12 2  - 2109 -  13 3  - 3402 -  11 3  - 3403 -  12

in example, id 3 should valid alarm, since 2 consecutive time values id have value > threshold. id 1 has single, isolated alarm, should filteres. id 2 there 2 alarms, not consecutive, should filtered.

something this:

10 - threshold 0 - minimum of time period 100000 - maximum of time period   select id, min(time)  ( select id, time,         (select max(time) t             time<t1.time            , id=t1.id            , value>10) lag_g,        (select max(time) t             time<t1.time            , id=t1.id            , value<=10) lag_l,        (select min(time) t             time>t1.time            , id=t1.id            , value>10) lead_g,        (select min(time) t             time>t1.time            , id=t1.id            , value<=10) lead_l  t t1 value>10 , time>=0 , time<=100000 ) t3 ifnull(lag_g,0)>ifnull(lag_l,0)       or       ifnull(lead_g,100000)<ifnull(lead_l,100000)  group id

sqlfiddle demo

this query works searching near records.

if need search records time (+1, -1 ) you've mentioned in comment try query:

select id, min(time) t t1 value>10       , time>=%s2 , time<=%s1   ,     (        exists(select 1 t value>10                                , id=t1.id                               , time=t1.time-1)        or         exists(select 1 t value>10                                , id=t1.id                               , time=t1.time+1)     )   group id

sqlfiddle demo


Comments

Post a Comment

Popular posts from this blog

curl - PHP fsockopen help required -

i trying work on cloudflare api , have found in documentation. unfortunately have no idea how can use in fsockopen or through curl. here example of post request. need know how can make request below data post using curl or fsockopen curl https://www.cloudflare.com/api_json.html -d 'a=cache_lvl' \ -d 'tkn=8afbe6dea02407989af4dd4c97bb6e25' \ -d 'email=sample@example.com' \ -d 'z=example.com' \ -d 'v=agg' here link cloudflare https://www.cloudflare.com/docs/client-api.html#s4.2 try one: $ch = curl_init("https://www.cloudflare.com/api_json.html"); curl_setopt($ch, curlopt_returntransfer,1); curl_setopt($ch, curlopt_followlocation, 1); curl_setopt($ch, curlopt_ssl_verifypeer,false); // handling of -d curl parameter here. $param = array( 'a' => 'cache_lvl', 'tkn' => '8afbe6dea02407989af4dd4c97bb6e25', 'email' => 'sample@example.com', 'z' =...
Read more

HTTP/1.0 407 Proxy Authentication Required PHP -

i working in restricted network/limited access internet. since have use proxy make web service call. here php code calling web service , response . $client = new soapclient("http: //www.xyz.com/abc/wsdls/login.wsdl", array("trace" => 1, "exceptions" => 1, 'proxy_host' => $proxy_host, 'proxy_port' => $proxy_port, 'proxy_login' => $proxy_login, 'proxy_password' => $proxy_password)); response is fatal error: uncaught soapfault exception: [wsdl] soap-error: parsing wsdl: couldn't load ' http://www.xyz.com/abc/wsdls/login.wsdl ' : failed load external entity if copy url error message , paste in browser(with same proxy settings) works. 2nd scenario is, if pass values instead of variables giving me diffarant response $client = new soapclient("http: //www.xyz.com/abc/wsdls/login.wsdl", array("trace" => 1, "exceptions" => 1, 'proxy_host' ...
Read more

c# - Resource not found error -

i have problem accessing method on homecontroller. show code of method : [httpget] public actionresult decriptidentifiantetredirige(string login_crypter, string mdp_crypter) { string loginacrypter = _globalmanager.protegemotdepasse(login_crypter); string mdpacrypter = _globalmanager.protegemotdepasse(mdp_crypter); user userapp = new models.user(login_crypter, mdp_crypter); if (userapp.authentificationvalidee(userapp.userlogin, userapp.password)) { session["name"] = userapp.userlogin; return redirecttoaction("accueil", "home"); } else { return redirecttoaction("validerauthentification", "home"); } } then in routeconfig.cs wrote route : routes.maproute( name: "authentificationapresdecryptage", url: "{controller}/{action}/{login_crypter}/{mdp_crypter}", defaults: new...
Read more