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• Synchronizing one or more databases with a master database - Foreign keys

  - by Ikke

  I'm using Google Gears to be able to use an application offline (I know Gears is deprecated). The problem I am facing is the synchronization with the database on the server. The specific problem is the primary keys or more exactly, the foreign keys. When sending the information to the server, I could easily ignore the primary keys, and generate new ones. But then how would I know what the relations are. I had one sollution in mind, bet the I would need to save all the pk for every client. What is the best way to synchronize multiple client with one server db. Edit: I've been thinking about it, and I guess seqential primary keys are not the best solution, but what other possibilities are there? Time based doesn't seem right because of collisions which could happen. A GUID comes to mind, is that an option? It looks like generating a GUID in javascript is not that easy. I can do something with natural keys or composite keys. As I'm thinking about it, that looks like the best solution. Can I expect any problems with that?

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• What happens to existing workspaces after upgrading to TFS 2010

  - by e-mre

  Hi, I was looking for some insight about what happens to existing workspaces and files that are already checked-out on people, after an upgrade to TFS2010. Surprisingly enough I can not find any satisfactory information on this. (I am talking about upgrading on new hardware by the way. Fresh TFS instance, upgraded databases) I've checked TFS Installation guide, I searched through the web, all I could find is upgrade scenarios for the server side. Nobody even mentions what happens to source control clients. I've created a virtual machine to test the upgrade process, The upgrade was successful and all my files and workspaces exist in the new server too. The problem is: The new TFS installation has a new instanceID. When I redirected on the clients to the new server, the client seemed unable to match files and file states in the workspace with the ones on the new server. This makes me wonder if it will be possible to keep working after the production upgrade. As I mentioned above I can not find anything on this, it would be great if anyone could point me to some paper or blog post about this. Thanks in advance...

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• Dynamic TextBox on LinkButton click

  - by Alex Peta

  I am creating dynamic TextBoxes in a page by clicking a LinkButton. However, after that, if the page is submitted, I can't find the items created dynamically, thus, can't send the information to the database. protected void lbAddTag_Click(object sender, EventArgs e) { for (int i = 0; i < 3;i++ ) { CreateTextBox("txtTag-" + i.ToString()); } } private void CreateTextBox(string ID) { TextBox txt = new TextBox(); txt.ID = ID; txt.Width = Unit.Pixel(300); //txt.TextChanged += new EventHandler(OnTextChanged); txt.AutoPostBack = false; tagsPanel.Controls.Add(txt); Literal lt = new Literal(); lt.Text = "<br /><br />"; tagsPanel.Controls.Add(lt); } If I put: foreach (Control c in tagsPanel.Controls) { if (c is TextBox) { lblError.Text += c.ClientID + " , "; } } in the lbAddTag_Click method I can see the items, and they exist, but if I submit the page and try to insert the values in the database nothing... Any hint is much appreciated.

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• Show values in TDropDownList in PRADO.

  - by Muhammad Sajid

  I m new to PRADO, I have a file Home.page with code: <%@ Title="Contact List" %> <h1>Contact List</h1> <a href="<%= $this->Service->constructUrl('insert')%>">Create New Contact</a> <br/> <com:TForm> <com:TDropDownList ID="personInfo"> <com:TListItem Value="value 1" Text="item 1" /> <com:TListItem Value="value 2" Text="item 2" Selected="true" /> <com:TListItem Value="value 3" Text="item 3" /> <com:TListItem Value="value 4" Text="item 4" /> </com:TDropDownList> </com:TForm> & Home.php with code <?php class Home extends TPage { /** * Populates the datagrid with user lists. * This method is invoked by the framework when initializing the page * @param mixed event parameter */ public function onInit($param) { parent::onInit($param); // fetches all data account information $rec = ContactRecord::finder()->findAll(); } } ?> the $rec contain array of all values. Now I want to show all name in Dropdown list. I tried my best but fail. Can anyone help me? Thanks

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• How to change XmlSchemaElement.SchemaType (or: difference between SchemaType and ElementSchemaType)

  - by Gregor

  Hey, I'm working on a XML Editor which gets all his information from the corresponding XSD file. To work with the XSD files I use the System.Xml.Schema Namespace (XmlSchema*). Because of an 'xsi:type' attribute in the XML I've to change the XmlSchemaType of an XmlSchemaElement. Until now I use in my code the 'ElementSchemaType' property of 'XmlSchemaElement'. The nice thing about it: it's read only. There is also in 'XmlSchemaElement' an 'SchemaType' property which is not read only, but always null (yes, XmlSchema and XmlSchemaSet are compiled). So how can I change the type of the 'XmlSchemaElement'? Or, also the same question: What is the diffrence between this two porperties? Some technical data: C#, .NET 3.5 The MSDN documentation is nearly the same for both: SchemaType Documentation: Gets or sets the type of the element. This can either be a complex type or a simple type. ElementSchemaType Documentation: Gets an XmlSchemaType object representing the type of the element based on the SchemaType or SchemaTypeName values of the element.

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• Reservation Solution for RealEstate integrating with Joomla

  - by Pennf0lio

  Hi, My client needs a Property (Just Land NO Houses) Reservation solution for their existing website (It runs in Joomla). I need some advice/Tips on what approach should I use. I'm looking for an Opensource solution that I can customize to my need. The Scenario: A buyer reserves a lot, A form appears gathers his details after that he/she pays for the reservation. FrontEnd: I need a form builder extension in Joomla that I could build custom form in gathering information (name, email, contact info, address...) from the buyer or the person who is reserving it. After I gather the info I need another extension that will handle the payment for reserving it. This is kinda shopping cart type approach, you see a product and the buy it. But would just need extra details. Backend: I can see all the details of the buyer from their name to the time they paid for a reservation. Thanks! P.S. I'm open to all Ideas. I'm not sure of this approach. Please let me know If you have some good Ideas or example.

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• rails 4 -- working with js format from ajax

  - by user101289

  I'm still working on learning Rails, and I have a page with team information that will get updated based on a team's icon click, which fires an ajax call to the controller to populate some tabs. I've read some good info about how to use format.js in the controller to render a partial from a js.coffee or js.erb file. The problem I'm running into is in the coffeescript I think. Right now, I'm getting some data called @schedules from the controller, and passing it to a schedule.js.coffee file that should populate a partial for each record returned and attach it to a table. // schedule.js.coffee $.each @schedules, (schedule) -> ($ '#schedule_data').append("<%= j render(partial: 'schedules/schedule', locals: { s: schedule }) %>") This throws an error `> undefined local variable or method `schedule' for #<#<Class:0x007fe535cd2900>:0x007fe535d32a30>` I tried simplifying the coffeescript to just log the output: $.each @schedules, (schedule) -> console.log(schedule) but this prints nothing. Am I missing something? I am very inexperienced with coffeescript, but it seems like I should be getting some data-- I verified that the schedule items do exist for this team item.

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• What caused the rails application crash?

  - by so1o

  I'm sure someone can explain this. we have an application that has been in production for an year. recently we saw an increase in number of support requests for people having difficulty signing into the system. after scratching our head because we couldn't recreate the problem in development, we decided we'll switch on debug logger in production for a month. that was june 5th. application worked fine with the above change and we were waiting. then yesterday we noticed that the log files were getting huge so we made another change in production config.logger = Logger.new("#{RAILS_ROOT}/log/production.log", 50, 1048576) after this change, the application started crashing while processing a particular file. this particular line of code was RAILS_DEFAULT_LOGGER.info "Payment Information Request: ", request.inspect as you can see there was a comma instead of a plus sign. this piece of code was introduced in Mar. the question is this: why did the application fail now? if changing the debug level caused the application to process this line of code it should have started failing on june 5th! why today. please someone help us. Are we missing the obvious here? if you dont have an answer, at least let us know we aren't the only one that are bonkers.

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• Which database I can used and relationship in it ??

  - by mimo-hamad

  My projece make me confused which I didn't find clear things that make me understand the required database and the relationships in it So, would a super one help me to solve it ?!! ;D this is required: 1) Model the data stored in the database (Identify the entities, roles, relationships, constraints, etc.) 2) Write the Oracle commands to create the database, find appropriate data, and populate the database 3) Write five different queries on your database, using the SELECT/FROM/WHERE construct provided in SQL. Your five queries should illustrate several different aspects of database querying, such as: a. Queries over more than one relation (by listing more than one relation in the FROM clause) b. Queries involving aggregate functions, such as SUM, COUNT, and AVG c. Queries involving complicated selects and joins d. Queries involving GROUP BY, HAVING or other similar functions. e. Queries that require the use of the DISTINCT keyword. And this the condition that we need to determine it to solve the required Q's above : 5) It is desired to develop an Internet membership club to buy products at special prices online. To join, new members must be referred by another existing member of the club. The system will keep the following information for each member: The member ID, referring member, birth date, member name, address, phone, mobile, credit card type, number and expiration date. The items are always shipped to the member's address noted in the membership application. The shipping fees will differ for each order.For each item to be requested, the member will select an item from a long list of possible items. For each item in the database, we store an item ID, an item name, description, and list price. The list price will be different from the actual sale price. The available quantity and the back-ordered quantity (the back-ordered quantity is the quantity on-order by the club from its suppliers) is also noted

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• mootools get data of child element of li?

  - by sea_1987

  Hi there, I am trying to get some information of a child element of an li using mootools, essentially my html looks like this, <li><a href="/home" id="home" class="nav-link">Home</a></li> I am wanting to be able get the id, class and href of the a tag using mootools, so far my javascript looks similar to this, $$('.rate').each(function(element,i){ element.addEvent('click', function(){ var myStyles = ['nostar', 'onestar', 'twostar', 'threestar', 'fourstar', 'fivestar', 'sixstar', 'sevenstar', 'eightstar', 'ninestar', 'tenstar']; myStyles.each(function(myStyle){ if(element.getParent().hasClass(myStyle)){ element.getParent().removeClass(myStyle) } }); myStyles.each(function(myStyle, index){ if(index == element.id){ element.getParent().toggleClass(myStyle); var req = new Request({ method:'post', url: '/recipes/save', data: {'rating' : element.id}, onRequest: function(){ alert('Request made. Please wait...');}, onComplete:function(response){ alert('Response:' + response);} }).send(); alert('Clicked '+element.id); alert(element.getChildren().get('href'); } }); }); }); The final alert in the script is my attempt to the child of the li(element) and its href.

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• Inline function and global variable issue in Javascript

  - by Natim

  I have some code here : http://bitbucket.org/natim/lo53_tp1/src/tip/part3/camions/medias/js/tracking.js That I use to draw some information about trucks direction. The problem come from a function defined in a for loop like this one : ... for(i = 0; i < nb_trucks; i++) { ... contentString = '<div id="content">'+ trucks[i]['name'] + '</div>'; current_window = new google.maps.InfoWindow({ content: contentString }); infosWindow.push(current_window); current_marker = new google.maps.Marker({ map: map, position: new google.maps.LatLng(trucks[i]['end']['lat'], trucks[i]['end']['lon']), draggable: false, title: trucks[i]['name'] }); markers.push(current_marker); google.maps.event.addListener(current_marker, 'click', function() { current_window.open(map, current_marker); }); } In this code, you can see the last block google.maps.event.addListener(current_marker, 'click', function() { current_window.open(map, current_marker); }); And my problem is that current_marker in the addListener parameters is different from the one inside the function. The current_window and the current_marker inside the function is overide at each loop turn. How can I get it right ? Thanks

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• Http authentication with apache httpcomponents

  - by matdan

  Hi, I am trying to develop a java http client with apache httpcomponents 4.0.1. This client calls the page "https://myHost/myPage". This page is protected on the server by a JNDIRealm with a login form authentication, so when I try to get https://myHost/myPage I get a login page. I tried to bypass it unsuccessfully with the following code : //I set my proxy HttpHost proxy = new HttpHost("myProxyHost", myProxyPort); //I add supported schemes SchemeRegistry supportedSchemes = new SchemeRegistry(); supportedSchemes.register(new Scheme("http", PlainSocketFactory .getSocketFactory(), 80)); supportedSchemes.register(new Scheme("https", SSLSocketFactory .getSocketFactory(), 443)); // prepare parameters HttpParams params = new BasicHttpParams(); HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1); HttpProtocolParams.setContentCharset(params, "UTF-8"); HttpProtocolParams.setUseExpectContinue(params, true); ClientConnectionManager ccm = new ThreadSafeClientConnManager(params, supportedSchemes); DefaultHttpClient httpclient = new DefaultHttpClient(ccm, params); httpclient.getParams().setParameter(ConnRoutePNames.DEFAULT_PROXY, proxy); //I add my authentication information httpclient.getCredentialsProvider().setCredentials( new AuthScope("myHost/myPage", 443), new UsernamePasswordCredentials("username", "password")); HttpHost host = new HttpHost("myHost", 443, "https"); HttpGet req = new HttpGet("/myPage"); //show the page ResponseHandler<String> responseHandler = new BasicResponseHandler(); String rsp = httpClient.execute(host, req, responseHandler); System.out.println(rsp); When I run this code, I always get the login page, not myPage. How can I apply my credential parameters to avoid this login form? Any help would be fantastic

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• Moving to an arbitrary position in a file in Python

  - by B Rivera

  Let's say that I routinely have to work with files with an unknown, but large, number of lines. Each line contains a set of integers (space, comma, semicolon, or some non-numeric character is the delimiter) in the closed interval [0, R], where R can be arbitrarily large. The number of integers on each line can be variable. Often times I get the same number of integers on each line, but occasionally I have lines with unequal sets of numbers. Suppose I want to go to Nth line in the file and retrieve the Kth number on that line (and assume that the inputs N and K are valid --- that is, I am not worried about bad inputs). How do I go about doing this efficiently in Python 3.1.2 for Windows? I do not want to traverse the file line by line. I tried using mmap, but while poking around here on SO, I learned that that's probably not the best solution on a 32-bit build because of the 4GB limit. And in truth, I couldn't really figure out how to simply move N lines away from my current position. If I can at least just "jump" to the Nth line then I can use .split() and grab the Kth integer that way. The nuance here is that I don't just need to grab one line from the file. I will need to grab several lines: they are not necessarily all near each other, the order in which I get them matters, and the order is not always based on some deterministic function. Any ideas? I hope this is enough information. Thanks!

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• CanCan polymorphic resource access problem

  - by Call 'naive' True

  Hi everybody, i don't quite understand how to restrict access to links in this particular case with CanCan. I always get "Edit" link displayed. So i believe the problem is in my incorrect definition of cancan methods(load_ and authorize_). I have CommentsController like that: class CommentsController < ApplicationController before_filter :authenticate_user! load_resource :instance_name => :commentable authorize_resource :article def index @commentable = find_commentable #loading our generic object end ...... private def find_commentable params.each { |name, value| if name =~ /(.+)_id$/ return $1.classify.constantize.includes(:comments => :karma).find(value) end } end end and i have in comments/index.html.erb following code that render file from other controller: <%= render :file => "#{get_commentable_partial_name(@commentable)}/show.html.erb", :collection => @commentable %> you can think about "#{get_commentable_partial_name(@commentable)}" like just "articles" in this case. Content of "articles/show.html.erb": <% if can? :update, @commentable %> <%= link_to 'Edit', edit_article_path(@commentable) %> | <% end %> my ability.rb: class Ability include CanCan::Ability def initialize(user) user ||= User.new # guest user if user.role? :admin can :manage, :all elsif user.role? :author can :read, [Article, Comment, Profile] can :update, Article, :user_id => user.id end end end relations with models is: class Comment < ActiveRecord::Base belongs_to :commentable, :polymorphic => true, :dependent => :destroy ... end class Article < ActiveRecord::Base has_many :comments, :as => :commentable, :dependent => :destroy ... end i have tried debug this issue like that user = User.first article = Article.first ability = Ability.new(user) ability.can?(:update, article) and i always get "= true" in ability check Note: user.role == author and article.user_id != user.id if you need more information please write thank's for your time && sorry for my english

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• Is the REST support in Spring 3's MVC Framework production quality yet?

  - by glenjohnson

  Hi all, Since Spring 3 was released in December last year, I have been trying out the new REST features in the MVC framework for a small commercial project involving implementing a few RESTful Web Services which consume XML and return XML views using JiBX. I plan to use either Hibernate or JDBC Templates for the data persistence. As a Spring 2.0 developer, I have found Spring 3's (and 2.5's) new annotations way of doing things quite a paradigm shift and have personally found some of the new MVC annotation features difficult to get up to speed with for non-trivial applications - as such, I am often having to dig for information in forums and blogs that is not apparent from going through the reference guide or from the various Spring 3 REST examples on the web. For deadline-driven production quality and mission critical applications implementing a RESTful architecture, should I be holding off from Spring 3 and rather be using mature JSR 311 (JAX-RS) compliant frameworks like RESTlet or Jersey for the REST layer of my code (together with Spring 2 / 2.5 to tie things together)? I had no problems using RESTlet 1.x in a previous project and it was quite easy to get up to speed with (no magic tricks behind the scenes), but when starting my current project it initially looked like the new REST stuff in Spring 3's MVC Framework would make life easier. Do any of you out there have any advice to give on this? Does anyone know of any commercial / production-quality projects using, or having successfully delivered with, the new REST stuff in Spring 3's MVC Framework. Many thanks Glen

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• Spring Integration 1.0 RC2: Streaming file content?

  - by gdm

  I've been trying to find information on this, but due to the immaturity of the Spring Integration framework I haven't had much luck. Here is my desired work flow: New files are placed in an 'Incoming' directory Files are picked up using a file:inbound-channel-adapter The file content is streamed, N lines at a time, to a 'Stage 1' channel, which parses the line into an intermediary (shared) representation. This parsed line is routed to multiple 'Stage 2' channels. Each 'Stage 2' channel does its own processing on the N available lines to convert them to a final representation. This channel must have a queue which ensures no Stage 2 channel is overwhelmed in the event that one channel processes significantly slower than the others. The final representation of the N lines is written to a file. There will be as many output files as there were routing destinations in step 4. *'N' above stands for any reasonable number of lines to read at a time, from [1, whatever I can fit into memory reasonably], but is guaranteed to always be less than the number of lines in the full file. How can I accomplish streaming (steps 3, 4, 5) in Spring Integration? It's fairly easy to do without streaming the files, but my files are large enough that I cannot read the entire file into memory. As a side note, I have a working implementation of this work flow without Spring Integration, but since we're using Spring Integration in other places in our project, I'd like to try it here to see how it performs and how the resulting code compares for length and clarity.

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• Storing date/times as UTC in database

  - by James

  I am storing date/times in the database as UTC and computing them inside my application back to local time based on the specific timezone. Say for example I have the following date/time: 01/04/2010 00:00 Say it is for a country e.g. UK which observes DST (Daylight Savings Time) and at this particular time we are in daylight savings. When I convert this date to UTC and store it in the database it is actually stored as: 31/03/2010 23:00 As the date would be adjusted -1 hours for DST. This works fine when your observing DST at time of submission. However, what happens when the clock is adjusted back? When I pull that date from the database and convert it to local time that particular datetime would be seen as 31/03/2009 23:00 when in reality it was processed as 01/04/2010 00:00. Correct me if I am wrong but isn't this a bit of a flaw when storing times as UTC? Example of Timezone conversion Basically what I am doing is storing the date/times of when information is being submitted to my system in order to allow users to do a range report. Here is how I am storing the date/times: public DateTime LocalDateTime(string timeZoneId) { var tzi = TimeZoneInfo.FindSystemTimeZoneById(timeZoneId); return TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, tzi).ToLocalTime(); } Storing as UTC: var localDateTime = LocalDateTime("AUS Eastern Standard Time"); WriteToDB(localDateTime.ToUniversalTime());

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• C++ How to read a string of text and create object of their class

  - by user1777711

  After reading a text file... The following information is available Point2D, [3, 2] Line3D, [7, 12, 3], [-9, 13, 68] Point3D, [1, 3, 8] Line2D, [5, 7], [3, 8] Point2D, [3, 2] Line3D, [7, -12, 3], [9, 13, 68] Point3D, [6, 9, 5] Point2D, [3, 2] Line3D, [70, -120, -3], [-29, 1, 268] Line3D, [25, -69, -33], [-2, -41, 58] Point3D, [6, 9, -50] The first data separate by the delimiter comma is the class name. for each of the 4 class Point2D,Line3D,Point3D,Line2D How do i like store them into relevant object base on their class means.. when it read first line Point2D, [3, 2] It will store it as Point2D object with the Data [3, 2] But the issue is what dataset should i pick, Vector, Set , Map or List I was thinking to actually create a data set then but i can't use new Point2D(); since Point2D is parent of Point3D Line2D is parent of Line3D and theres no parent class of Point2D and Line2D. how can i like create a object of them in a data set like e.g Vector so Vector[0] is of Point2D class with data [3,2] , then Vector[1] is of Line3D class with data [7, 12, 3], [-9, 13, 68] Thanks for helping.!

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• Is DB logging more secure than file logging for my PHP web app?

  - by iama

  I would like to log errors/informational and warning messages from within my web application to a log. I was initially thinking of logging all of these onto a text file. However, my PHP web app will need write access to the log files and the folder housing this log file may also need write access if log file rotation is desired which my web app currently does not have. The alternative is for me to log the messages to the MySQL database since my web app is already using the MySQL database for all its data storage needs. However, this got me thinking that going with the MySQL option is much better than the file option since I already have a configuration file with the database access information protected using file system permissions. If I now go with the log file option I need to tinker the file and folder access permissions and this will only make my application less secure and defeats the whole purpose of logging. Is this correct? I am using XAMPP for development and am a newbie to LAMP. Please let me know your recommendations for logging. Thanks.

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• OnConnect event not firing when using TClientSocket inside a TThread on non-blocking mode

  - by mathematician1975

  I am trying to make use of Borlands TClientSocket component in non-blocking mode inside a multithreaded C++ Windows application. I am creating multiple threads (classes derived from TThread), each of which creates its own TClientSocket object. I then assign member functions of the thread class to act as event handlers for the OnConnect, OnDisconnect and OnSocketError events of the socket. The problem I am having here is that whenever I call the TClientSocket::Open() function from within the TThread::Execute() function, the OnConnect event never fires. However, When I call the Open() function from the VCL thread prior to the TThread::Execute() function getting called, all of the events fire and I can use the thread-socket combination as I would like. Now I have not read anything in documentation that says that TClientSocket should not be used in non-blocking mode when used inside a thread, but it appears to me that there is perhaps something wrong conceptually in the way I am trying to use this class. Borland documentation is quite poor on the subject and these components have now been deprecated so reliable information is hard to come by. Despite being deprecated I have to use them as there is no alternative in the Builder 6 package I have. Can anyone please advise me if there is a right/wrong way to use TThread and a non-blocking TClientSocket in combination. I have never had problems using it as part of the VCL thread and never had problems using TServerSocket before and I really cannot understand why some events are not firing.

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• Lost in dates and timezones

  - by Sebastien

  I'm working on an application that stores conferences with their start and end date. Up until now, I was developing in Belgium and my server is in France, so everything is in the same timezone, no problem. But today, I'm in San Francisco, my server is in France and I noticed I have a bug. I'm setting dates from a Flex client (ActionScript automatically adapts date display according to client local timezone, which is GMT-8 for me today. My server runs on Hibernate and MySQL in France (GMT+1). So when I look at my database using phpMyAdmin, I see a date set to "2010-06-07 00:00:01" but in my Flex client it displays "2010-06-06 15:00:01". Ultimately, what I want is that the dates are displayed in the local timezone of the event, which is the date I set it to. So when I'm in Belgium and I set the start date of an event to be "2010-06-07 00:00:01" I want to retrieve it that way. But I'm lost as to what layer adapts what. Is timezone stored in DATETIME MySQL columns (I can't see it in MySQL)? Does Hibernate to anything to it when it transfers it to java.lang.Date that has Timezone information? And ultimately, what is the best way to solve this mess?

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• Reversible numerical calculations in Prolog

  - by user8472

  While reading SICP I came across logic programming chapter 4.4. Then I started looking into the Prolog programming language and tried to understand some simple assignments in Prolog. I found that Prolog seems to have troubles with numerical calculations. Here is the computation of a factorial in standard Prolog: f(0, 1). f(A, B) :- A > 0, C is A-1, f(C, D), B is A*D. The issues I find is that I need to introduce two auxiliary variables (C and D), a new syntax (is) and that the problem is non-reversible (i.e., f(5,X) works as expected, but f(X,120) does not). Naively, I expect that at the very least C is A-1, f(C, D) above may be replaced by f(A-1,D), but even that does not work. My question is: Why do I need to do this extra "stuff" in numerical calculations but not in other queries? I do understand (and SICP is quite clear about it) that in general information on "what to do" is insufficient to answer the question of "how to do it". So the declarative knowledge in (at least some) math problems is insufficient to actually solve these problems. But that begs the next question: How does this extra "stuff" in Prolog help me to restrict the formulation to just those problems where "what to do" is sufficient to answer "how to do it"?

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• Python: Created nested dictionary from list of paths

  - by sberry2A

  I have a list of tuples the looks similar to this (simplified here, there are over 14,000 of these tuples with more complicated paths than Obj.part) [ (Obj1.part1, {<SPEC>}), (Obj1.partN, {<SPEC>}), (ObjK.partN, {<SPEC>}) ] Where Obj goes from 1 - 1000, part from 0 - 2000. These "keys" all have a dictionary of specs associated with them which act as a lookup reference for inspecting another binary file. The specs dict contains information such as the bit offset, bit size, and C type of the data pointed to by the path ObjK.partN. For example: Obj4.part500 might have this spec, {'size':32, 'offset':128, 'type':'int'} which would let me know that to access Obj4.part500 in the binary file I must unpack 32 bits from offset 128. So, now I want to take my list of strings and create a nested dictionary which in the simplified case will look like this data = { 'Obj1' : {'part1':{spec}, 'partN':{spec} }, 'ObjK' : {'part1':{spec}, 'partN':{spec} } } To do this I am currently doing two things, 1. I am using a dotdict class to be able to use dot notation for dictionary get / set. That class looks like this: class dotdict(dict): def __getattr__(self, attr): return self.get(attr, None) __setattr__ = dict.__setitem__ __delattr__ = dict.__delitem__ The method for creating the nested "dotdict"s looks like this: def addPath(self, spec, parts, base): if len(parts) > 1: item = base.setdefault(parts[0], dotdict()) self.addPath(spec, parts[1:], item) else: item = base.setdefault(parts[0], spec) return base Then I just do something like: for path, spec in paths: self.lookup = dotdict() self.addPath(spec, path.split("."), self.lookup) So, in the end self.lookup.Obj4.part500 points to the spec. Is there a better (more pythonic) way to do this?

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• Learning libraries without books or tutorials

  - by Kawili-wili

  While many ask questions about where to find good books or tutorials, I'd like to take the opposite tack. I consider myself to be an entry-level programmer ready to move up to mid-level. I have written code in c, c++, c#, perl, python, clojure, vb, and java, so I'm not completely clueless. Where I see a problem in moving to the next level is learning to make better use of the literally hundreds upon hundreds of libraries available out there. I seem paralyzed unless there is a specific example in a book or tutorial to hand-hold me, yet I often read in various forums where another programmer attempts to assist with a question. He/she will look through the docs or scan the available classes/methods in their favorite IDE and seem to grok what's going on in a relatively short period of time, even if they had no previous experience with that specific library or function. I yearn to break the umbilical chord of constantly spending hour upon hour searching and reading, searching and reading, searching and reading. Many times there is no book or tutorial, or if there is, the discussion glosses over my specific needs or the examples shown are too far off the path for the usage I had in mind or the information is outdated and makes use of deprecated components or the library itself has fallen out of mainstream, yet is still perfectly usable (but no docs, books, or tutorials to hand-hold). My question is: In the absence of books or tutorials, what is the best way to grok new or unfamiliar libraries? I yearn to slicken the grok path so I can get down to the business of doing what I love most -- coding.

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• Why am I returning empty records when querying in mysql with php?

  - by Brian Bolton

  I created the following script to query a table and return the first 30 results. The query returns 30 results, but they do not have any text or information. Why would this be? The table stores Vietnamese characters. The database is mysql4. Here's the page: http://saomaidanang.com/recentposts.php Here's the code: <?php header( 'Content-Type: text/html; charset=utf-8' ); //CONNECTION INFO $dbms = 'mysql'; $dbhost = 'xxxxx'; $dbname = 'xxxxxxx'; $dbuser = 'xxxxxxx'; $dbpasswd = 'xxxxxxxxxxxx'; $conn = mysql_connect($dbhost, $dbuser, $dbpasswd ) or die('Error connecting to mysql'); mysql_select_db($dbname , $conn); //QUERY $result = mysql_query("SET NAMES utf8"); $cmd = 'SELECT * FROM `phpbb_posts_text` ORDER BY `phpbb_posts_text`.`post_subject` DESC LIMIT 0, 30 '; $result = mysql_query($cmd); ?> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html dir="ltr"> <head> <title>recent posts</title> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> </head> <body> <p> <?php //DISPLAY while ($myrow = mysql_fetch_row($result)) { echo 'post subject:'; echo(utf8_encode($myrow ['post_subject'])); echo 'post text:'; echo(utf8_encode($myrow ['post_text'])); } ?> </p> </body>

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