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  • Nested and complicated select statement

    - by Selase
    What i want to do here is simple...display an ivestigators ID and him corresponding name... That can be easily done from the users table by selecting based on the user type. However i want to select only some type of investigators. The analogy here is investigators are assigned to an exhibit for them to investigate. One investigator can be assigned to a maximum of 3 cases only. Now during the assigning of investigators, i want to write a select statement that would retrieve only investigatorID's that have been assigned to less than or equal to 2 cases. I have included exhibit and users table that shows sample data below. Now i sort of have an idea that i will have to first of all pick out all the investigators by their ID from the users list and then filter them through the exhibit table by dropping those assigned to 3 cases and leaving just those with two cases. then afterwards i use this IDs to select the Investigators name. the big questions is how do i write the statement??

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  • What is a mantainable way of saving "star rating" in a database?

    - by Montecristo
    I'll use the jQuery plugin for presenting the user with a nice interface The request is to display 5 stars, up to a total score of 10 (2 points per star). By now I thought about using 7/10 as a format for that value, but what if at some point in the future I'll receive a request like We would like to give users more choice, let's increase the total score to 20 (so that each star contributes with a maximum of 4 points) I'll end up with a table with mixed values for the "star rating" column: some will be like 7/10 while others will be like 14/20. Is it ok for you to have this difference in the database and deal with it in the logic layer to have it consistent? Or is preferred another way so that querying the table will not result in inconsistent results outside the application? Maybe floating point values could help me, is it better to store that value as a number less than or equal to one? So in each of the two examples the resulting value stored in the database would be 0,7, as a number, not a varchar, which can be queried also outside the application. What do you think?

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  • MySQL running on an EC2 m1.small instance has high load but low memory usage, possible resolutions?

    - by Tosh
    I have a MySQL server 5.0.75 Ubuntu, on an m1.small instance running on Amazon's EC2 as part of an application. During peak usage the server load will rise very high, while the memory usage stays low and the application server is no longer responsive since it's waiting for query results. The application server has only 5-8 apache processes running (mod_perl processes). The data directory uses only 140MB of data so the MyIsam tables aren't very big. The queries are pretty complicated with some big joins being performed, and the application makes a lot of queries. mysqltuner reports everything OK except "Maximum possible memory usage: 1.7G (99% of installed RAM)" but I'm nowhere close to using that. My question is, where should I be looking to fix this? Is this something that can be tuned away, or do I just need a larger instance/server? Googling indicates either or also upgrading MySQL server. Any pointers in the right direction would be greatly appreciated, thanks! EDIT: I just discovered this in my slow queries log: # Time: 101116 11:17:00 # User@Host: user[pass] @ [host] # Query_time: 4063 Lock_time: 1035 Rows_sent: 0 Rows_examined: 19960174 SELECT * FROM contacts WHERE contacts.contact_id IN (SELECT external_id FROM contact_relations WHERE external_table = 'contacts' AND contact_id IN (SELECT contact_id FROM contacts WHERE (company_name like '%%butan%%%' OR country like '%%butan%%%' OR city like '%%butan%%%' OR email1 like '%%butan%%%') AND (company_name is not null and company_name != ''))); Which actually brings up a different but related question: If I have a contact table containing: John Smith,The Fun Factory,555-1212,[email protected] What's the best way to search for that record using "factory" as a search key? Fulltext rarely seems to find items in the middle of a word, for example "actor" should bring up "Factory"

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  • t-sql help with recursive sort of query

    - by stackoverflowuser
    Hi Based on the following table ID Path --------------------------------------- 1 \\Root 2 \\Root\Node0 3 \\Root\Node0\Node1 4 \\Root\Node0\Node2 5 \\Root\Node3 6 \\Root\Node3\Node4 7 \\Root\Node5 ... N \\Root\Node5\Node6\Node7\Node8\Node9\Node10 so on... There are around 1000 rows in this table. I want to display individual node in seperate columns. Maximum columns to be displayed 5 (i.e. node till 5 level deep). So the output will look as below ID Path Level 0 Level 1 Level 2 Level 3 Level 4 Level 5 ---------------------------------------------------------------------------------------- 1 \\Root Root Null Null Null Null Null 2 \\Root\Node0 Root Node 0 Null Null Null Null 3 \\Root\Node0\Node1 Root Node 0 Node 1 Null Null Null 4 \\Root\Node0\Node2 Root Node 0 Node 2 Null Null Null 5 \\Root\Node3 Root Node 3 Null Null Null Null 6 \\Root\Node3\Node4 Root Node 3 Node 4 Null Null Null 7 \\Root\Node5 Root Node 5 Null Null Null Null ... N (see in above table) Root Node 5 Node 6 Node 7 Node 8 Node 9 The only way i can think of is to open a cursor, loop through each row and perform string split, just fetch the first 5 nodes and then insert into a temp table. Pls. suggest. Thanks

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  • MySQL: Limit rows linked to each joined row

    - by SolidSnakeGTI
    Hello, Specifications: MySQL 4.1+ I've certain situation that requires certain result set from MySQL query, let's see the current query first & then ask my question: SELECT thread.dateline AS tdateline, post.dateline AS pdateline, MIN(post.dateline) FROM thread AS thread LEFT JOIN post AS post ON(thread.threadid = post.threadid) LEFT JOIN forum AS forum ON(thread.forumid = forum.forumid) WHERE post.postid != thread.firstpostid AND thread.open = 1 AND thread.visible = 1 AND thread.replycount >= 1 AND post.visible = 1 AND (forum.options & 1) AND (forum.options & 2) AND (forum.options & 4) AND forum.forumid IN(1,2,3) GROUP BY post.threadid ORDER BY tdateline DESC, pdateline ASC As you can see, mainly I need to select dateline of threads from 'thread' table, in addition to dateline of the second post of each thread, that's all under the conditions you see in the WHERE CLAUSE. Since each thread has many posts, and I need only one result per thread, I've used GROUP BY CLAUSE for that purpose. This query will return only one post's dateline with it's related unique thread. My questions are: How to limit returned threads per each forum!? Suppose I need only 5 threads -as a maximum- to be returned for each forum declared in the WHERE CLAUSE 'forum.forumid IN(1,2,3)', how can this be achieved. Is there any recommendations for optimizing this query (of course after solving the first point)? Notes: I prefer not to use sub-queries, but if it's the only solution available I'll accept it. Double queries not recommended. I'm sure there's a smart solution for this situation. Appreciated advice in advance :)

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  • HTML5 on iPhone Safari - data stored by localStorage does not always persist. Why?

    - by Aerodyne
    Hi, I write a simple iPhone web app using HTML5's localStorage. Tests on a 2G device show that data stored using localStorage does not persist after the Safari process is killed although the opened Safari windows are remembered. The data is also lost in a case where I am on a different site on a different Safari window, then I change the window to where the web app in subject is shown. When Safari loads the page it automatically refreshes the page. Then the data is lost. This is a simple test code: <html> <head> <meta name="viewport" content="height=device-height, width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" /> </head> <body> <script> alert("1:" + localStorage.getItem("test")); localStorage.setItem("test", "123"); alert("2:" + localStorage.getItem("test")); </script> </body> As far as I understand the data should persist! Can anyone shed some light on this behavior? What should I do to get the persistence to work? Thanks! Tom.

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  • avoiding code duplication in Rails 3 models

    - by Dustin Frazier
    I'm working on a Rails 3.1 application where there are a number of different enum-like models that are stored in the database. There is a lot of identical code in these models, as well as in the associated controllers and views. I've solved the code duplication for the controllers and views via a shared parent controller class and the new view/layout inheritance that's part of Rails 3. Now I'm trying to solve the code duplication in the models, and I'm stuck. An example of one of my enum models is as follows: class Format < ActiveRecord::Base has_and_belongs_to_many :videos attr_accessible :name validates :name, presence: true, length: { maximum: 20 } before_destroy :verify_no_linked_videos def verify_no_linked_videos unless self.videos.empty? self.errors[:base] << "Couldn't delete format with associated videos." raise ActiveRecord::RecordInvalid.new self end end end I have four or five other classes with nearly identical code (the association declaration being the only difference). I've tried creating a module with the shared code that they all include (which seems like the Ruby Way), but much of the duplicate code relies on ActiveRecord, so the methods I'm trying to use in the module (validate, attr_accessible, etc.) aren't available. I know about ActiveModel, but that doesn't get me all the way there. I've also tried creating a common, non-persistent parent class that subclasses ActiveRecord::Base, but all of the code I've seen to accomplish this assumes that you won't have subclasses of your non-persistent class that do persist. Any suggestions for how best to avoid duplicating these identical lines of code across many different enum models?

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  • Ruby On Rails - Contact form not sending email via localhost

    - by anonymousxxx
    similar problem Rails contact form not working guides: https://github.com/thomasklemm/email_form_rails rails 3.2.x app\models\message.rb class Message include ActiveAttr::Model include ActiveModel::Validations attribute :name attribute :email attribute :subject attribute :body attr_accessible :name, :email, :subject, :body validates_presence_of :name validates_presence_of :email validates :email, email_format: { message: "is not looking like a valid email address"} validates_presence_of :subject validates_length_of :body, maximum: 500 end app\mailers\contact_form.rb class ContactForm < ActionMailer::Base default from: "[email protected]" default to: "[email protected]" def email_form(message) @message = message mail subject: "#{message.subject} #{message.name}" mail body: "#{message.body}" end end development.rb config.action_mailer.delivery_method = :smtp config.action_mailer.perform_deliveries = true config.action_mailer.smtp_settings = { :address => "smtp.gmail.com", :port => 587, :domain => "mydomain.com", :user_name => "[email protected]", :password => "mypassword", :authentication => :plain, :enable_starttls_auto => true } config.action_mailer.default_url_options = { :host => "localhost:3000" } output in command Started POST "/email" for 127.0.0.1 at 2012-09-04 22:10:40 +0700 Processing by HomeController#send_email_form as HTML Parameters: {"utf8"="v", "authenticity_token"="w39BLqCrjTMm4RRi/Sm5hZoEpcw46 npyRy/RS0h48x0=", "message"={"name"="anonymousxxx", "email"="[email protected]", "subject"="Test", "body"="send email"}, "commit"="Create Message"} Redirected to localhost:3000/home/contact Completed 302 Found in 1ms (ActiveRecord: 0.0ms) but email (message) no receive my email,..

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  • How can I find the common ancestor of two nodes in a binary tree?

    - by Siddhant
    The Binary Tree here is not a Binary Search Tree. Its just a Binary Tree. The structure could be taken as - struct node { int data; struct node *left; struct node *right; }; The maximum solution I could work out with a friend was something of this sort - Consider this binary tree (from http://lcm.csa.iisc.ernet.in/dsa/node87.html) : The inorder traversal yields - 8, 4, 9, 2, 5, 1, 6, 3, 7 And the postorder traversal yields - 8, 9, 4, 5, 2, 6, 7, 3, 1 So for instance, if we want to find the common ancestor of nodes 8 and 5, then we make a list of all the nodes which are between 8 and 5 in the inorder tree traversal, which in this case happens to be [4, 9, 2]. Then we check which node in this list appears last in the postorder traversal, which is 2. Hence the common ancestor for 8 and 5 is 2. The complexity for this algorithm, I believe is O(n) (O(n) for inorder/postorder traversals, the rest of the steps again being O(n) since they are nothing more than simple iterations in arrays). But there is a strong chance that this is wrong. :-) But this is a very crude approach, and I'm not sure if it breaks down for some case. Is there any other (possibly more optimal) solution to this problem?

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  • [PHP, CSS, & ?] fixed width div, resizing text on the fly based on length

    - by Andrew Heath
    Let's say you've got a simple fixed-width layout that pulls a title from a MySQL database. CSS: #wrapper { width: 800px; } h1 { width: 100%; } HTML: <html> <body> <div id="wrapper"> <h1> $titleString </h1> </div> </body> </html> But the catch is, the length of the title string pulled from your MySQL database varies wildly. Sometimes it might be 10 characters, sometimes it might be 80. It's possible to establish a min & max character count. How, if at all possible, do I get the text-size of my <h1>$titleString</h1> to enlarge/decrease on-the-fly such that the string is only ever on one line and best fit to that line length? I've seen a lot of questions about resizing the div - but in my case the div must always be 100% (800px) and I want to best-fit the title. Obviously a maximum text-size value would have to be set so 5 character strings don't become gargantuan. Does anyone have a suggestion? I'm only using PHP/MySQL/CSS on this page at the moment, but incorporation of another language is fine if it means I can solve the problem. The only thing I can think of is a bruteforce approach whereby through trial and error I establish acceptable string character count ranges matched with CSS em sizes, but that'd be a pretty ugly implementation from the code side.

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  • C -- Basic Struct questions

    - by Ryan Yu
    So I'm trying to learn C right now, and I have some basic struct questions I'd like to clear up: Basically, everything centers around this snippet of code: #include <stdio.h> #include <stdlib.h> #define MAX_NAME_LEN 127 typedef struct { char name[MAX_NAME_LEN + 1]; unsigned long sid; } Student; /* return the name of student s */ const char* getName (const Student* s) { // the parameter 's' is a pointer to a Student struct return s->name; // returns the 'name' member of a Student struct } /* set the name of student s If name is too long, cut off characters after the maximum number of characters allowed. */ void setName(Student* s, const char* name) { // 's' is a pointer to a Student struct | 'name' is a pointer to the first element of a char array (repres. a string) s->name = name; } /* return the SID of student s */ unsigned long getStudentID(const Student* s) { // 's' is a pointer to a Student struct return s->sid; } /* set the SID of student s */ void setStudentID(Student* s, unsigned long sid) { // 's' is a pointer to a Student struct | 'sid' is a 'long' representing the desired SID s->sid = sid; } I've commented up the code in an attempt to solidify my understanding of pointers; I hope they're all accurate. So anyway, I have a feeling that setName and setStudentID aren't correct, but I'm not exactly sure why. Can someone explain? Thanks!

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  • 32-bit JVM on 64-bit Windows crashes on launch with -Xmx1300m and plenty of free memory

    - by Konrad Garus
    I'm struggling with Java heap space settings. The default Java on Windows is the 32-bit client regardless of OS version (that's what Oracle recommends to all users). It appears to set max heap size to 256 MB by default, and that is too little for me. I use a custom launcher to start the application. I would like it to use more memory on computers with plenty RAM, and default to -Xmx512m on those with less RAM. As far as I'm aware, the only way is the static -Xmx setting (that has to be set on launch). I have a user who has 8 GB RAM, 64-bit Windows and 32-bit Java 7. Maximum memory visible to the JVM is 4G (as returned by querying OperatingSystemMXBean). I understand why, no issue. For some reason my application is unable to start for this user with -Xmx1300m, even though he has 2.3G free memory. He closed some applications (having 5G free memory), and still it would not launch. The error reported to me was: error occured during init of vm could not reserve enough space for object heap What's going on? Could it be that the 32-bit JVM is only able to address the "first" 4G of memory and has to have a 1300M block available within those first 4 gigabytes? How can I solve this problem, except for asking everyone to install 64-bit Java (what is unlikely to be acceptable)?

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  • Regular Expressions .NET

    - by Fosa
    I need a regular expression for some arguments that must match on a string. here it is... The string exists out of minimum 8 en maximum 20 characters. These characters of this string may be characters of the alfabet or special chars --With other words..all charachters except from the whitespaces In the complete string there must be atleast 1 number. The string cannot start with a number or an underscore The last 2 characters of the string must be identical, But it doenst matter if those last --identical characters are capital or non-capital (case insensitive) Must match all : +234567899 a_1de*Gg xy1Me*__ !41deF_hij2lMnopq3ss C234567890123$^67800 *5555555 sDF564zer"" !!!!!!!!!4!!!!!!!!!! abcdefghijklmnopq9ss May not match : Cannot be less then 8 or more then 20 chars: a_1+Eff B41def_hIJ2lmnopq3stt Cannot contain a whitespace: A_4 e*gg b41def_Hij2l nopq3ss Cannot start with a number or an underscore: __1+Eff 841DEf_hij2lmnopq3stt cannot end on 2 diffrent characters: a_1+eFg b41DEf_hij2lmnopq3st Cannot be without a number in the string: abCDefghijklmnopqrss abcdef+++dF !!!!!!!!!!!!!!!!!!!! ------------------------------------------------------ This is what I have so far...But I'm really breaking my head on this... If you Don't know the answer completely it's not a problem... I just want to get in the right direction ([^0-9_])(?=.*\d)(\S{8,20})(?i:[\S])\1

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  • Capacity Allocation

    - by user1708730
    I am new to VB in Excel. I have a unique requirement for capacity allocation which I want to automate using excel VB and facing hard time doing so, hope you can help. The objective is to maximize profit by allocating maximum capacity to those products which have highest profit potential first. Every Month I get demand along with backlogs of previous month. I need to allocate capacity to backlogs of previous month first and then only the remaining capacity for fresh demand. There are two primary constraints: 1.The number of working days in a month (variable) 2. Not all products can be made on every production line and out of same product may be different for each production line Also there will be losses whenever there is a change over from one SKU to another depending upon the Variant Type and size of next product. If there is variant change then 8 hours of production loss needs to be accounted and 4 hours in case of size change(8 hours in case of both). I have attached sample data(Actual data has 10 production lines and 50 products) https://rapidshare.com/files/1822719405/Sample%20Data.xlsx?bin=1 Thanks in advance for help!

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  • Store multiple values in a session variable

    - by user458790
    Hi, Before I ask my doubt, please consider this scenario that a user on my website have a profileID. With this profileID are associated some pluginID's. For eg: User1 might have 2, 3 and 5 plugins associated with its profile. When the user logs in, I store the profileID of the user in a session variable cod. At a certain page, the user tries to edit the plugins associated with his profile. So, on that page, I have retrieve those pluginID's from the DB. I have applied this code but this fetches only the maximum pluginID from the DB and not all the pluginID's. SqlCommand cmd1 = new SqlCommand("select plugin_id from profiles_plugins where id=(select id from profiles_plugins where profile_id=" + Convert.ToInt32(Session["cod"]) + ")", con); SqlDataReader dr1 = cmd1.ExecuteReader(); if (dr1.HasRows) { while (dr1.Read()) { Session["edp1"] = Convert.ToInt32(dr1[0]); } } dr1.Close(); cmd1.Dispose(); I was trying to figure out how can I store multiple pluginID's in this session variable? Thanks

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  • Create a model that switches between two different states using Temporal Logic?

    - by NLed
    Im trying to design a model that can manage different requests for different water sources. Platform : MAC OSX, using latest Python with TuLip module installed. For example, Definitions : Two water sources : w1 and w2 3 different requests : r1,r2,and r3 - Specifications : Water 1 (w1) is preferred, but w2 will be used if w1 unavailable. Water 2 is only used if w1 is depleted. r1 has the maximum priority. If all entities request simultaneously, r1's supply must not fall below 50%. - The water sources are not discrete but rather continuous, this will increase the difficulty of creating the model. I can do a crude discretization for the water levels but I prefer finding a model for the continuous state first. So how do I start doing that ? Some of my thoughts : Create a matrix W where w1,w2 ? W Create a matrix R where r1,r2,r3 ? R or leave all variables singular without putting them in a matrix I'm not an expert in coding so that's why I need help. Not sure what is the best way to start tackling this problem. I am only interested in the model, or a code sample of how can this be put together. edit Now imagine I do a crude discretization of the water sources to have w1=[0...4] and w2=[0...4] for 0, 25, 50, 75,100 percent respectively. == means implies Usage of water sources : if w1[0]==w2[4] -- meaning if water source 1 has 0%, then use 100% of water source 2 etc if w1[1]==w2[3] if w1[2]==w2[2] if w1[3]==w2[1] if w1[4]==w2[0] r1=r2=r3=[0,1] -- 0 means request OFF and 1 means request ON Now what model can be designed that will give each request 100% water depending on the values of w1 and w2 (w1 and w2 values are uncontrollable so cannot define specific value, but 0...4 is used for simplicity )

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  • drawing graphs in php

    - by user434885
    i am using php to generate graphs from arrays. I wish to create multiple graphs on the same page as i need to design a summary report from answers extracted from a database. Currently i am using this code and am only able to get one single graph. what additions to the code do i need to make to get multiple graphs? <?php function draw_graph($values) { // Get the total number of columns we are going to plot $columns = count($values); // Get the height and width of the final image $width = 300; $height = 200; // Set the amount of space between each column $padding = 5; // Get the width of 1 column $column_width = $width / $columns ; // Generate the image variables $im = imagecreate($width,$height); $gray = imagecolorallocate ($im,0xcc,0xcc,0xcc); $gray_lite = imagecolorallocate ($im,0xee,0xee,0xee); $gray_dark = imagecolorallocate ($im,0x7f,0x7f,0x7f); $white = imagecolorallocate ($im,0xff,0xff,0xff); // Fill in the background of the image imagefilledrectangle($im,0,0,$width,$height,$white); $maxv = 0; // Calculate the maximum value we are going to plot for($i=0;$i<$columns;$i++)$maxv = max($values[$i],$maxv); // Now plot each column for($i=0;$i<$columns;$i++) { $column_height = ($height / 100) * (( $values[$i] / $maxv) *100); $x1 = $i*$column_width; $y1 = $height-$column_height; $x2 = (($i+1)*$column_width)-$padding; $y2 = $height; imagefilledrectangle($im,$x1,$y1,$x2,$y2,$gray_dark); } header ("Content-type: image/png"); imagepng($im); imagedestroy($im); } $values = array("23","32","35","57","12"); $values2 = array("123","232","335","157","102"); draw_graph($values2); draw_graph($values);//no output is coming draw_graph($values2);//no output is coming draw_graph($values);//no output is coming ?>

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  • Function to even out multiple arrays

    - by Moak
    Assume I have a function evenOut($array, $limit){ //returns exactly $limit items } and this data $animals = array(); $animals['barn'] = array_fill(0,20, 'b'); $animals['forest'] = array_fill(0,20, 'f'); $animals['house'] = array_fill(0,20, 'h'); $animals['mountain'] = array_fill(0,20, 'm'); I want to return a maximum of 10 animals, however they should be spread out evenly among the locations they come from. so if i did evenOut($animals,8); i'd get 2 of each('b','b','f','f','h','h','m','m',) evenOut($animals,2); should return ('b','f') if I have this data $animals = array(); $animals['barn'] = array_fill(0,1, 'b'); $animals['forest'] = array_fill(0,3, 'f'); $animals['house'] = array_fill(0,8, 'h'); $animals['mountain'] = array_fill(0,1, 'm'); evenOut($animals,8); expected result would be ('b','f','f','f','h','h','h','m',) evenOut($animals,10); expected result would be ('b','f','f','f','h','h','h','h','h','m',) $animals = array(); $animals['barn'] = array_fill(0,0, 'b'); $animals['forest'] = array_fill(0,3, 'f'); evenOut($animals,10); expected result would be ('f','f','f') I'm not sure how I should approach this, I am hoping there is a simple way

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  • Generating all possible subsets of a given QuerySet in Django

    - by Glen
    This is just an example, but given the following model: class Foo(models.model): bar = models.IntegerField() def __str__(self): return str(self.bar) def __unicode__(self): return str(self.bar) And the following QuerySet object: foobar = Foo.objects.filter(bar__lt=20).distinct() (meaning, a set of unique Foo models with bar <= 20), how can I generate all possible subsets of foobar? Ideally, I'd like to further limit the subsets so that, for each subset x of foobar, the sum of all f.bar in x (where f is a model of type Foo) is between some maximum and minimum value. So, for example, given the following instance of foobar: >> print foobar [<Foo: 5>, <Foo: 10>, <Foo: 15>] And min=5, max=25, I'd like to build an object (preferably a QuerySet, but possibly a list) that looks like this: [[<Foo: 5>], [<Foo: 10>], [<Foo: 15>], [<Foo: 5>, <Foo: 10>], [<Foo: 5>, <Foo: 15>], [<Foo: 10>, <Foo: 15>]] I've experimented with itertools but it doesn't seem particularly well-suited to my needs. I think this could be accomplished with a complex QuerySet but I'm not sure how to start.

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  • Page URL and database organization.

    - by shurik2533
    I want that its name would be the page address. For example, if page has heading "Some Page", than its address should be http://somesite/some_page/. "some_page"-name generated by system automatically. "some_page" - is the unique identifier of page. The problem in that the user in the future can enter a name which already exists that will cause an error. It is necessary to find an optimum variant of the decision of a problem for great volumes of the data. I have solved a problem as follows: The page identifier in a database is the name of page and a suffix which is by default equal to zero. At page addition there is a check on existence. If such page does not exist, the suffix is equal 0 and its name is "some_page", if page is exist, than - search for the maximum number of a suffix and suffix=suffix+1 and page name become "some_page_1". For this I create in a database the compound key from fields "suffix" and "pageName": Table Pages suffix|pageName |pageTitle 0 |some_page |Some Page 1 |some_page |Some Page 0 |other_page|Other Page Addition of pages occurs through stored procedure: CREATE PROCEDURE addPage (pageNameVal VARCHAR(100), pageTitleVal VARCHAR(100)) BEGIN DECLARE v INT DEFAULT 0; SELECT MAX(suffix) FROM pages WHERE pageName=pageNameVal INTO v; IF v >= 0 THEN SET v = v + 1; ELSE SET v = 0; END IF; INSERT INTO pages (suffix, pageName) VALUES (pageNameVal, v, pageTitleVal); END; Whether there are more the best decisions?

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  • How to get the real, actual duration of an MP3 file (VBR or CBR) server-side

    - by Cummander Checkov
    I used to calculate the duration of MP3 files server-side using ffmpeg - which seemed to work fine. Today i discovered that some of the calculations were wrong. Somehow, for some reason, ffmpeg will miscalculate the duration and it seems to happen with variable bit rate mp3 files only. When testing this locally, i noticed that ffmpeg printed two extra lines in green. Command used: ffmpeg -i song_9747c077aef8.mp3 ffmpeg says: [mp3 @ 0x102052600] max_analyze_duration 5000000 reached at 5015510 [mp3 @ 0x102052600] Estimating duration from bitrate, this may be inaccurate After a nice, warm google session, i found some posts on this, but no solution was found. I then tried to increase the maximum duration: ffmpeg -analyzeduration 999999999 -i song_9747c077aef8.mp3 After this, ffmpeg returned only the second line: [mp3 @ 0x102052600] Estimating duration from bitrate, this may be inaccurate But in either case, the calculated duration was just plain wrong. Comparing it to VLC i noticed that here the duration is correct. After more research i stumbled over mp3info - which i installed and used. mp3info -p "%S" song_9747c077aef8.mp3 mp3info then returned the CORRECT duration, but only as an integer, which i cannot use as i need a more accurate number here. The reason for this was explained in a comment below, by user blahdiblah - mp3info is simply pulling ID3 info from the file and not actually performing any calculations. I also tried using mplayer to retrieve the duration, but just as ffmpeg, mplayer is returning the wrong value. Now i ran out of options. If somebody knows how to get around this, any hints, tips, guides or corrections are welcome! Thank You!

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  • python recursive iteration exceeding limit for tree implementation

    - by user3698027
    I'm implementing a tree dynamically in python. I have defined a class like this... class nodeobject(): def __init__(self,presentnode=None,parent=None): self.currentNode = presentnode self.parentNode = parent self.childs = [] I have a function which gets possible childs for every node from a pool def findchildren(node, childs): # No need to write the whole function on how it gets childs Now I have a recursive function that starts with the head node (no parent) and moves down the chain recursively for every node (base case being the last node having no children) def tree(dad,children): for child in children: childobject = nodeobject(child,dad) dad.childs.append(childobject) newchilds = findchildren(child, children) if len(newchilds) == 0: lastchild = nodeobject(newchilds,childobject) childobject.childs.append(lastchild) loopchild = copy.deepcopy(lastchild) while loopchild.parentNode != None: print "last child" else: tree(childobject,newchilds) The tree formation works for certain number of inputs only. Once the pool gets bigger, it results into "MAXIMUM RECURSION DEPTH EXCEEDED" I have tried setting the recursion limit with set.recursionlimit() and it doesn't work. THe program crashes. I want to implement a stack for recursion, can someone please help, I have gone no where even after trying for a long time ?? Also, is there any other way to fix this other than stack ?

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  • Is there a quality, file-size, or other benefit to JPEG sizes being multiples of 8px or 16px?

    - by davebug
    The JPEG compression encoding process splits a given image into blocks of 8x8 pixels, working with these blocks in future lossy and lossless compressions. [source] It is also mentioned that if the image is a multiple 1MCU block (defined as a Minimum Coded Unit, 'usually 16 pixels in both directions') that lossless alterations to a JPEG can be performed. [source] I am working with product images and would like to know both if, and how much benefit can be derived from using multiples of 16 in my final image size (say, using an image with size 480px by 360px) vs. a non-multiple of 16 (such as 484x362). In this example I am not interested in further alterations, editing, or recompression of the final image. To try to get closer to a specific answer where I know there must be largely generalities: Given a 480x360 image that is 64k and saved at maximum quality in Photoshop [example]: Can I expect any quality loss from an image that is 484x362 What amount of file size addition can I expect (for this example, the additional space would be white pixels) Are there any other disadvantages to growing larger than the 8px grid? I know it's arbitrary to use that specific example, but it would still be helpful (for me and potentially any others pondering an image size) to understand what level of compromise I'd be dealing with in breaking the non-8px grid. The key issue here is a debate I've had is whether 8-pixel divisible images are higher quality than images that are not divisible by 8-pixels.

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  • merging two tables, while applying aggregates on the duplicates (max,min and sum)

    - by cloudraven
    I have a table (let's call it log) with a few millions of records. Among the fields I have Id, Count, FirstHit, LastHit. Id - The record id Count - number of times this Id has been reported FirstHit - earliest timestamp with which this Id was reported LastHit - latest timestamp with which this Id was reported This table only has one record for any given Id Everyday I get into another table (let's call it feed) with around half a million records with these fields among many others: Id Timestamp - Entry date and time. This table can have many records for the same id What I want to do is to update log in the following way. Count - log count value, plus the count() of records for that id found in feed FirstHit - the earliest of the current value in log or the minimum value in feed for that id LastHit - the latest of the current value in log or the maximum value in feed for that id. It should be noticed that many of the ids in feed are already in log. The simple thing that worked is to create a temporary table and insert into it the union of both as in Select Id, Min(Timestamp) As FirstHit, MAX(Timestamp) as LastHit, Count(*) as Count FROM feed GROUP BY Id UNION ALL Select Id, FirstHit,LastHit,Count FROM log; From that temporary table I do a select that aggregates Min(firsthit), max(lasthit) and sum(Count) Select Id, Min(FirstHit),Max(LastHit),Sum(Count) FROM @temp GROUP BY Id; and that gives me the end result. I could then delete everything from log and replace it with everything with temp, or craft an update for the common records and insert the new ones. However, I think both are highly inefficient. Is there a more efficient way of doing this. Perhaps doing the update in place in the log table?

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  • UITableViewCell: how to verify the kind of accessoryType in all cells?

    - by R31n4ld0_
    Hello, Guys. I have a UITableView in that some cells are marked with UITableViewCellAccessoryCheckmark at the initialization of the view. When the user selects another row, I have to check if the maximum number of selected rows was achieved before. To do that, I used the code bellow: - (NSInteger)tableView:(UITableView *)tableView numberOfSelectedRowsInSection:(NSInteger)section{ NSInteger numberOfRows = [self tableView:tableView numberOfRowsInSection:section]; NSInteger numberOfSelectedRows = 0; for (int i = 0; i < numberOfRows; i++) { UITableViewCell *otherCell = [tableView cellForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:section]]; if (otherCell.accessoryType == UITableViewCellAccessoryCheckmark) { numberOfSelectedRows++; } } return numberOfSelectedRows; } If my number of rows is, as example, 20, the variable numberOfRows is setted correctly with 20. Lets say that 13 rows already are marked with UITableViewCellAccessoryCheckmark. So, numberOfSelectedRows should be 13 after the loop, but only the marked and VISIBLE cells are considered. So, if I have 9 cells showed and 7 are marked, the numberOfSelectedRows returns 7 instead of 13 (but the for iterate 20 times, as expected). Is this a correct behavior of UITableView or it is a bug of iPhone simulator? Thanks in advance.

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