Using MYSQL conditional statements and variables within a query -

-

hi cant seem construct mysql query im after.

say have result of 2 columns: 1) browser name , 2) browser count.

where gets complicated want once 90% of total count has been reached rename other browsers others , mark left on percentage accordingly.

i know can total count variable before begin main statement:

select @total := count(id) browser_table start "2010%";

then can group results browser:

select browser, count(id) visits browser_table start "2010%" group browser

i know need whack in case statement (and counter variable) sort columns not sure of how implement above query:

case    when counter >= 0.9* @total 'other'   else browser end browser;

hope makes sense? time....

here's 1 approach...

you can calculate running total based on this answer. example:

set @rt := 0; select     browser,     visits,     (@rt := @rt + visits) running_total     (         select             browser,             count(id) visits                     browser_table                     start '2010%'         group             browser         order             visits desc     ) sq ;


once have in place, can build on create 'other' category:

set @threshold := (select count(id) browser_table start '2010%') * 0.90; set @rt := 0; select     browser,     sum(visits) total_visits     (         select             if (@rt < @threshold, browser, 'other') browser,             visits,             (@rt := @rt + visits) running_total                     (                 select                     browser,                     count(id) visits                                     browser_table                                     start '2010%'                 group                     browser             ) sq1         order             visits desc     ) sq2 group     browser order     total_visits desc ;

Comments

Post a Comment

Popular posts from this blog

android - Spacing between the stars of a rating bar? -

-
ho can set spacing beween stars? thats ratingbar: ratingbar = (ratingbar) inflater.inflate(r.layout.ratingbar, null); ratingbar.setlayoutparams(new layoutparams(layoutparams.wrap_content, layoutparams.wrap_content)); the layout: <?xml version="1.0" encoding="utf-8"?> <ratingbar xmlns:android="http://schemas.android.com/apk/res/android" style="@style/mystyle" android:layout_alignparentright="true" android:layout_height="19dp" android:layout_width="wrap_content" android:numstars="5"> </ratingbar> the style: <style name="mystyle" parent="@android:style/widget.ratingbar"> <item name="android:progressdrawable">@drawable/android_r2_ratingstar_yellow</item> <item name="android:indeterminatedrawable">@drawable/android_r2_ratingstar_grey</item> </style> thanks, cheers you have ...
Read more

html - Instapaper-like algorithm -

-
does of algorithm extracts contents webpage? instapaper ? there 2 steps instapaper does: find main content block on page (excluding headers, footers, menus etc) from content block extract , format text to find content block (typically html block element, div containing key page text content) instapaper uses algorithm 1 used readability . can @ source of readability.js see what's going on, @ core tries find area on page highest text/link ratio, although has other simple scoring metrics (e.g. off top of head, things ratio of text commas, para elements etc) go heuristics. once have identified root node element, relevant content, you'll need format it, if want can pull node element containing text out of source document , insert yours, in reality you'll want remove existing styles , apply own, standard , feel. if want output nice text-only can use jericho's renderer . update1 : should mention else instapaper - follow 'pagination' links (...
Read more

c# - How to execute a particular part of code asynchronously in a class -

-
i creating speech recognition engine that's going respond user commands.i have created button enable , disable speech recognition per user convenience.i have used dispose() of speech engine disable speech recoginition.here code private void button1_click(object sender, routedeventargs e) { engineon = !engineon; if (engineon) { speechengine = speech.createspeechengine(); //speech class creates , returns new speech engine. speechengine.audiolevelupdated += new eventhandler<audiolevelupdatedeventargs>(speechengine_audiolevelupdated); // use system's default microphone speechengine.setinputtodefaultaudiodevice(); speechengine.loadgrammar(new dictationgrammar()); // start listening speechengine.recognizeasync(recognizemode.multiple); } else { speechclass.myengine.dispose(); } } but disposal of speech obj...
Read more