How to randomly select within a column category in MySQL -

-

How do you select a fixed number of column cost per line?

For example, I have a MySQL database of forums, for example, I have a MySQL database of a forum, where the column has the thread ID, Answer ID (the answer to the post that started the thread ) And poster IDs I randomly want to start 4 threads from each poster.

You might have the name of the table "threads", maybe something like this should be done

< Blockquote>

SELECT * RAND by thread order (LIMIT 4;

I do not know how efficient it is, but possibly not recommended with a bigger table. Perhaps generating random numbers in PHP or other languages ​​is a better option.


Comments

Post a Comment

Popular posts from this blog

winforms - C# Form - Property Change -

-
I have a form that has a property named car A class with many properties. The Properties is being displayed on the current car on the basis of some user actions that are being displayed. So I have to know whether the property has been allocated or set to zero. I'm aware of INotifyPropertyChanged , but in my case I'm not sure that since this change I have changed my car properties car do not want to monitor the property. Any idea how to accomplish this? In advance thank you If you have created a true asset in your class then You should be a great and setter, you can add the code directly to the form property in order to take action on the basis of "form": Public partial category Form 1: form {public form 1 () {InitializeComponent (); } // define car square public class car {public string name = string. Empty; } // private car to keep the value of the current car private variable _car = null; // Property of public form which you can ru...
Read more

java - Algorithm negotiation fail SSH in Jenkins -

-
I am trying to do SSH on the local server from Jenkins, but the following error has been thrown: [SSH] Exception: Algorithm negotiation fail com.jcraft.jsch.JSchException: algorithm talk com.jcraft.jsch.Session.receive_kexinit (Session.javaatar20) at com.jcraft.jsch.Session.connect (Sesson at com.jcraft.jsch.Session.connect (Session.java:150) at org.jvnet.hudson.plugins.SSHSite.createSession (SSHSite.java:141) on failed failed org.jvnet.hudson.plugins. java: 286) .SSHS on org.jvnet.hudson.plugins.SSHBuildWrapper.executePreBuildScript (SSHBuildWrapper.java:75) on Org.jvnet.hudson.plugins.SSHBuildWrapper.setUp (SSHBuildWrapper.java59) ite.executeCommand (SSHSite.java151) on hudson.model.Build $ BuildExecution.doRun hudson.model.AbstractBuild $ AbstractBuildExecution.run (AbstractBuild.java:533) to (Build.java:154) hudson.model.Run.execute ( Run.java:1754) in ended .model.FreeStyleBuild.run (FreeStyl hudson.model.ResourceController.execute (ResourceController.java:89) on hudson.mod...
Read more

java - Messages from .properties file do not display UTF-8 characters -

-
Image
In the form of a title, I can only add that if I enter the html file manually, then it Okay. View Rolver: & lt; Bean id = "templorellolver" class = "org.thymeleaf.templateresolver.ServletContextTemplateResolver" & gt; & Lt; Property name = "prefix" value = "/ web-nf / templates" /> & Lt; Property name = "suffix" value = ". Html" /> & Lt; Property Name = "Template Mode" Value = "HTML5" /> & Lt; Asset name = "cacheable" value = "wrong" /> & Lt; Property Name = "characterEncoding" value = "UTF-8" /> & Lt; / Bean & gt; & Lt; Bean id = "Template Engine" class = "org.thymeleaf.spring3.SpringTemplateEngine" & gt; & Lt; Property Name = "Temploreolar" ref = "Templarolver" /> & Lt; / Bean & gt; & Lt; Bean square = "org.thymeleaf.spring3.view.Thymel...
Read more