sql - How to select most recent values? -

-

I have a logging table to store with several checks: 

  create table [Log] Int IDENTITY (1, 1) No Taps, [minutes] datetime not null, [ProbeID] int 0 minus, [value] float (24) zero zero default 0.0, contract log_PK primary key [LogID]) [Normally, each probe generates a value every minute] [Log in] ([minute], [ProbeID], [value])

Some examples output: 

  log ID minutes probed mother N ====== =============================== 873875 2014-07-27 09:36 1972 24.4 873876 2014-07 -27 09:36 2001 29.7 873877 2014-07-27 09:36 3781 19.8 873878 2014-07-27 09:36 1963 25.6 873879 2014-07-27 09:36 2002 22.9 873880 2014-07-27 09:36 1959 -30.1 873881 2014-07-27 09:36 2005 20.7 873882 2014-07-27 09:36 1234 23.8 873883 2014-07-27 09:36 1970 19.9 873884 2014-07-27 09:36 1991 22.4 873885 2014-07 -27 09:37 1958 1.7 873886 2014-07-27 09:37 1962 21.3 873887 2014-07-27 09:37 1020 23.1 873888 2014-07 -27 09:38 1972 24.1 873889 2014-07-27 09:38 3781 20.1 873890 2014-07-27 09:38 2001 30 873891 2014-07-27 09:38 2002 23.4 873892 2014-07-27 09:38 1963 26 873893 2014-07-27 09:38 2005 20.8 873894 2014-07- 27 09:38 1234 23.7 873895 2014-07-27 09:38 1970-19.8 873896 2014-07-27 09:38 1991 22.7 873897 2014-07- 27 09:39 195 8 1.4 873898 2014-07-27 09:39 1962 22.1 873899 2014-07-27 09:39 1020 23.1

The latest readings for each investigation C What is the most efficient way to achieve?

For example the product (note: "value" is not maximum () or an average ()): 

  log id min probid value ===== ============================== 873899 27-Jul-2014 09:39 1020 3.1 873894 27-Jul-09 09:38 1234 23.7 873897 27-July-2014 09:39 1958 1.4 873880 27-Jul-09 09: 36 1959-30.1 8738 9 27-July-2015 09:39 1962 22.1 8738 9 27-July-2014 09:38 1963 26 8738 9 27-July-2014 09:38 1970 19.8 873888 27-July-2015 09:38 1972 24.1 873896 27-Jul-2014 09:38 1991 22.7 873890 27-Jul-2014 09:38 2001 30 873891 27- July-2014 09:38 2002 23.4 873893 27-Jul-2014 09:38 2005 20.8 873889 27-Jul-2014 09:38 3881 20.1.

This is another way Select from Log L * * where minute = (Select Max X (Ext.) From Log X where x.probeid = l.probeid) < P> You can compare performance plan w / a bela -


Comments

Post a Comment

Popular posts from this blog

java - org.apache.http.ProtocolException: Target host is not specified -

-
I have written a simple httprequest / response code and I am getting this error below: I used to type in my classpath httpclient, httpcore, common -Codecs and general logging. I am very new to Java and I do not know what's going on here. Please help me. code: import org.apache.http.client.HttpClient; Import org.apache.http.client.methods.HttpGet; Import org.apache.http.HttpResponse; Import org.apache.http.impl.client.HttpClientBuilder; Import org.apache.http.Header; Import org.apache.http.HttpHeaders; Public class UnshorteningUrl {public static zero main (string [] args throws exception {HttpGet request = zero; HTTP Client Client = HTTP ClientBuilder.credit (). Build (); Try {Request = New HTTP Gate ("trib.me/1lBFzSi"); HttpResponse httpResponse = client.execute (request); Header [] header = httpResponse.getHeaders (HttpHeaders.LOCATION); // Preconditions.checkState (headers.length == 1); String new url = header [0] .getValue (); System.out.println ("new url...
Read more

java - Gradle dependencies: compile project by relative path -

-
Is it possible to specify a dependency on another gradeal project in the granular (in android studios) outside the current project limits? For example, with a relative path like this: dependence {collection project ('../../ stdlib / dagger'}} MyApp (path / user / foo / workspace / mypad) The app (Path / User / Foo / Workspace / MyPass / App) And I have an Android Library Project with 3 subdomules: stdlib (path is / user / foo / Utilities (Path / User / Foo / Workspace / Stadlib / Utilis) http (Path / User / Foo / Workspace / Stadlib / HT) / Li> What I have to do is compile the Dagger, Util, http module in the MyApp project. The Stidelib Library module under heavy development And MyApp will grow in the form of Growth, so I do not want to push them into a Mewen repository. I am a little change. is likely to add another Gredle projects in some way? I will push the study library into the Maven repository after the source is in search of a temp...
Read more

ruby on rails - Object doesn't support #inspect when used with .include -

-
So I have participated in a glitch error that I do not even know how to debug. I am very new to the railing, so it has kicked my ass well when I use the .includes (school) seen by the student, it gives a blue box error, But when I look at any other model and .includes (school) , the school works just fine. class student & lt; ActiveRecord :: Base has has_many: relationships, foreign_key: "liker_id", dependent :: has_many: matches, foreign_key: "student_1_id", dependent :: deleted belong_to: school belong_to: conference belong_to: would_you_rather belong_to: home city belong_to: year is_to: Major and class school & lt; on the console activatecord :: Affiliate for the base: conference includes: respondent, class: "school", foreign_key: "rival_id" (e.g. For: School) Select SQL generated Select "School". * "School" from "school" "ID" IN (1) error message back NoMethodError: u...
Read more