Search Results

Search found 14275 results on 571 pages for 'exam questions'.

Page 502/571 | < Previous Page | 498 499 500 501 502 503 504 505 506 507 508 509  | Next Page >

• How to create several records in only one dynamic form?

  - by Fernando

  Hi experts, please help me with a simple PHP doubt. I have a simple form: < form action="foo" Person: < a href="javascript:addmore();"Add More < /form Every time the user clicks Add More two new input fields will be dynamically created using jQuery. This can be done several times in a same form. < form action="foo" Person: < a href="javascript:addmore();"Add More < /form Each pair (name and last_name) should create on record in my db. Two Questions: 1) What is the best option for input id? Appending a counter is the best option? 2) How can I handle it in the backend using php? Let me know if you need more info. Thanks in advance.

  Read the article

• Strange response from WCF service, how to return json easily

  - by Exitos

  I want to get a service to respond with just JSON. I have written the following code: namespace BM.Security { [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class AssocFileService { [OperationContract] [WebGet(ResponseFormat = WebMessageFormat.Json)] public List<Person> GetPeople(int message) { List<Person> myList = new List<Person>(); Person p = new Person() { Age = 28, Name="Name1" }; Person p2 = new Person() { Age = 26, Name = "Name2" }; myList.Add(p); myList.Add(p2); return myList; } } [DataContract] public class Person { [DataMember] public string Name { get; set; } [DataMember] public int Age { get; set; } } } But im getting the following JSON back which is really wierd... { "d" : [ { "Age" : 28, "Name" : "Name1", "__type" : "Person:#Bm.Security" }, { "Age" : 26, "Name" : "Name2", "__type" : "Person:#BM.Security" } ] } I'm totally stumped by the "d" no idea where that has come from. And also by the __type variable, no thanks don't really want that in my Json :-( How do I set the root node in my data to replace that d? Where did the d come from? So many questions... Hope someone can help....

  Read the article

• Would there be a market for this idea (cross platform VM for iPhone OS)

  - by Tzury Bar Yochay

  For a long time I wondered if the following idea worth a nickel or just a waste of time and energy. I am willing to start a project which will provide a kind of a VM for all iPxxx apps - so developed once for iPxxx can run on a Macbook, iMac, Linux, Android and windows (desktop and mobile). You get the idea, right? I want to do to the current iPhone SDK, the same as what Mono did to Microsoft .Net and perhaps a more complete set of implementation. I tend to believe that if overnight all apps on appstore become available on the android market as well that would be a mini revolution. Think about running iPad apps on every tablet that will come out to the market in the future. Wouldn't it be fantastic to all the developers, which from now on, can write once and sell everywhere? The main questions which I ask myself repeatedly is: "Is This Legal?" - I mean, say I have done this, would apple's lawyers will start sending me all kinds of nasty emails? I am willing to hear your opinion about this idea as well as if some of you willing and able to join forces and start this open source project.

  Read the article

• Velocity CTP: can we 'search' for objects?

  - by Stato Machino

  It appears that 'tags' allow us to associate a 'search term' with the objects placed into the Velocity cache space. However, these can only be queried within a 'region'. Further, regions somehow limit the locality of objects in the cache to a single server (or maybe something kinda like that). So this appears to make it hard to perform any operation for which the unique Id of the cached item is not persisted or continuously available to the application that stores and retrieves objects to and from the cache. In any case, I can't see an easy way to 'cleanse' the cache of objects or to find objects across the entire cache that may share some prefix, postfix or infix values in the cache key so that i can clear out the cache of object repeatedly created in unit tests, for example. And I am unsure about the consequences of regions being associated with single server cache locations. So I would appreciate any help with the following questions: What is the difference between a 'distributed cache' (called a 'partitioned' cache??) when using regions, and a 'local cache'? 1.a. In particular, are the region-oriented values in a distributed cache visible through a cache factory that is configured to 'see' the entire cache space? Are the operations of creating and removing 'regions' efficient enough that it would be reasonable to create a region and a group of tags for each bundle of objects that need to be cached? 2.a. Or does this just push the problem of scoping the 'search for objects' up the chain because the ability of the DataCache object to query down through regions and tags as limited as querying for the cache keys of objects themselves. Thanks, Stato

  Read the article

• How to disable Rails submit buttons alongside Prototype helpers & RJS?

  - by Jesse

  I'm trying to follow this post http://stackoverflow.com/questions/576240/how-can-i-unobtrusively-disable-submit-buttons-with-javascript-and-prototype but I can't get it to work. The form triggers an RJS function, so I need to keep the helpers' onclick events intact. The RJS returns/reloads the same forms along with two new texts. I'm really confused. Here is my rails code for the forms: .span-20#comparison / new comparison . . . / voting forms (also reloaded) .span-4.prepend-3.append-6 - form_remote_tag :action => url_for(:controller => :comparisons), :method => :post do = hidden_field_tag :poem1_id, poems[:a].id = hidden_field_tag :poem2_id, poems[:b].id = hidden_field_tag :response, 1 = submit_tag "Vote for me", :disabled => false, :disable_with => 'Vote for me', :class => "compare" .span-4.append-3.last - form_remote_tag :action => url_for(:controller => :comparisons), :method => :post do = hidden_field_tag :poem1_id, poems[:a].id = hidden_field_tag :poem2_id, poems[:b].id = hidden_field_tag :response, 2 = submit_tag "Vote for me", :disable_with => 'Vote for me', :class => "compare" .span-4.prepend-8.append-8.prepend-top.last - form_remote_tag :action => url_for(:controller => :comparisons), :method => :post do = hidden_field_tag :poem1_id, poems[:a].id = hidden_field_tag :poem2_id, poems[:b].id = hidden_field_tag :response, 'draw' = submit_tag "Declare Draw", :disable_with => 'Declare Draw', :class => "compare" RJS page.replace_html :comparison, :partial => 'poems', :object => @poems page.insert_html :top, :previous, :partial => 'comparison', :object => @comparison page << "Effect.ScrollTo($('top'));"

  Read the article

• GIT: head has dissapeared, want to merge it into master.

  - by samgoody

  The top image is the output of: git reflog. The bottom is what GITK in GIT GUI (msysgit) shows me when I look at all branch history. The last few commits do not show on GIT GUI. Why do they not show on GITK (at least as a branch or something)? How do I merge them into master? I gather this happened when I checked out tag 0.42. Why is that not the same as master? (I had tagged the master in its latest state) When I click push, why does the remote repo claim to be up to date.. shouldn't it try to update these commits into whatever branch they are in? The first of the questions is important - I would like to begin to understand what GIT is thinking. It's more oracle than logic at this point. If it makes a difference to see the earlier history, the project is a [pretty powerful] JS color picker that can be viewed here in its entirety.

  Read the article

• call function inside a nested jquery plugin

  - by tchoesang

  There are many topics related to my question and i have been through most of them, but i haven't got it right. The closest post to my question is the following: http://stackoverflow.com/questions/1042072/how-to-call-functions-that-are-nested-inside-a-jquery-plugin Below is the jquery plugin i am using. On resize, the element sizes are recalculated. I am now trying to call the function resizeBind() from outside of the jquery plugin and it gives me error I tried the following combinations to call the function $.fn.splitter().resizeBind() $.fn.splitter.resizeBind() Any ideas, where i am getting wrong? ;(function($){ $.fn.splitter = function(args){ //Other functions ...... $(window).bind("resize", function(){ resizeBind(); }); function resizeBind(){ var top = splitter.offset().top; var wh = $(window).height(); var ww = $(window).width(); var sh = 0; // scrollbar height if (ww <0 && !jQuery.browser.msie ) sh = 17; var footer = parseInt($("#footer").css("height")) || 26; splitter.css("height", wh-top-footer-sh+"px"); $("#tabsRight").css("height", splitter.height()-30+"px"); $(".contentTabs").css("height", splitter.height()-70+"px"); } return this.each(function() { }); }; })(jQuery);

  Read the article

• How to find a function of application with ollydbg?

  - by user3725506

  Let's say i released the application below. using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; namespace WindowsFormsApplication2 { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { MessageBox.Show("Hello World!","Message Box"); } } } Now here is my questions: How to find the function of button which is responsible to show message box after pressing the button with ollydbg? How to disable the button click ? Notes:this must be done with ollydbg only. Assume that i don't have access to the code. A step-by-step example would be greatly appreciated.

  Read the article

• Best way to run multiple queries per second on database, performance wise?

  - by Michael Joell

  I am currently using Java to insert and update data multiple times per second. Never having used databases with Java, I am not sure what is required, and how to get the best performance. I currently have a method for each type of query I need to do (for example, update a row in a database). I also have a method to create the database connection. Below is my simplified code. public static void addOneForUserInChannel(String channel, String username) throws SQLException { Connection dbConnection = null; PreparedStatement ps = null; String updateSQL = "UPDATE " + channel + "_count SET messages = messages + 1 WHERE username = ?"; try { dbConnection = getDBConnection(); ps = dbConnection.prepareStatement(updateSQL); ps.setString(1, username); ps.executeUpdate(); } catch(SQLException e) { System.out.println(e.getMessage()); } finally { if(ps != null) { ps.close(); } if(dbConnection != null) { dbConnection.close(); } } } And my DB connection private static Connection getDBConnection() { Connection dbConnection = null; try { Class.forName(DB_DRIVER); } catch (ClassNotFoundException e) { System.out.println(e.getMessage()); } try { dbConnection = DriverManager.getConnection(DB_CONNECTION, DB_USER,DB_PASSWORD); return dbConnection; } catch (SQLException e) { System.out.println(e.getMessage()); } return dbConnection; } This seems to be working fine for now, with about 1-2 queries per second, but I am worried that once I expand and it is running many more, I might have some issues. My questions: Is there a way to have a persistent database connection throughout the entire run time of the process? If so, should I do this? Are there any other optimizations that I should do to help with performance? Thanks

  Read the article

• What's the steps for SQL optimization and changes without reflect live system ?

  - by Space Cracker

  we have a big portal that build using SharePoint 2007 , asp.net 3.5 , SQL Server 2005 .. many developers work in it since 01/2008 and we are now doing huge analysis for current SQL Databases [not share-point DB ] to optimize and enhance it. The main db have about 330 table and 1720 stored procedure (SP) created from 01/2008 till now Many table names / Columns is very long and we want to short it we found SP names is written in 25 format :( , some of them are very complex and also we want to rename many SP parameters need to be renamed one of the biggest table is Registered user table, that will be spitted in more than one table for some optimization, many columns name will be changed I searched for the way that i can rename table names ,columns and i found SQL refactor tool but i still trying it .. my questions : Is SQl Refactor is the best tool for renaming ? or is there any other one ? if i want to make it manually, is there any references or best practice for that ? How can i do such changes in fast and stable way .. i search for recommendations and case studies if exist ?

  Read the article

• How to access parents' members from a inner class in WPF?

  - by black sensei

  Hello Experts! I'm trying to do scheduled operation let's say to check for user's credit left via web service call and update the user interface. i've tried with quartz.net to implement the scheduling bit.i created an inner class in the window class i need to update.That inner class has the method that calls the webservice and the result needs to be displayed back to the UI. here is an example of what i did. public partial class Window2 : Window { private int i; public Window2() { InitializeComponent(); } public class Myclass :IJob { public void Execute(JobExecutionContext context) { string result = doMyOperation(); //i'll like to call parent label member of name lblNotif //is something like parent.lblNotif.Content = result; //possible? } public string doMyOperation() { //calling the wermethod to retreive user's balance return result = service.GetUsersBalace(user); } } } Well the quartz bit is working and this post is not about quartz. here are my questions Question 1 : How is it possible to access Window2 controls, for instace lable lblNotif? Question 2 : If my thinking about this is wrong, what is done as best practice to solve my kind of problem, where an application need to do an operation let's say every 5mn and update the the UI. Question 3 : i at first tried to use the backgroundworker and i felt like i can't do the scheduling bit with it.Is that correct or i'm wrong. thanks for those who commented already and sorry for those who didn't get the meaning of my post.I hope this will be a bit clearer.Thanks for reading

  Read the article

• create CLLocationCoordinate2D from array

  - by shani

  I have a plist with dictionary of array's with coordinates (stored as strings). I want to create a CLLocationCoordinate2D from every array and crate an overlay for the map. I did that - NSString *thePath = [[NSBundle mainBundle] pathForResource:@"Roots" ofType:@"plist"]; NSDictionary *pointsDic = [[NSDictionary alloc] initWithContentsOfFile:thePath]; NSArray *pointsArray = [NSArray arrayWithArray:[pointsDic objectForKey:@"roade1"]]; CLLocationCoordinate2D pointsToUse[256]; for(int i = 0; i < 256; i++) { CGPoint p = CGPointFromString([pointsArray objectAtIndex:i]); pointsToUse[i] = CLLocationCoordinate2DMake(p.x,p.y); NSLog(@"coord %f",pointsToUse [i].longitude); NSLog(@"coord %f",pointsToUse [i].latitude); } MKPolyline *myPolyline = [MKPolyline polylineWithCoordinates:pointsToUse count:256]; [[self mv] addOverlay:myPolyline]; but the app is crashing without any error. (BTW when i remove the addOverLay method the app does not crash). I have 2 questions- What am i doing wrong? I have tried to set the pointsArray count as the argument for the CLLocationCoordinate2D like that - CLLocationCoordinate2D pointsToUse[pointsArray count]; And i am getting an error. How can i set the CLLocationCoordinate2D dynamically ? Thanks for any help. Shani

  Read the article

• Python: Calling method A from class A within class B?

  - by Tommo

  There are a number of questions that are similar to this, but none of the answers hits the spot - so please bear with me. I am trying my hardest to learn OOP using Python, but i keep running into errors (like this one) which just make me think this is all pointless and it would be easier to just use methods. Here is my code: class TheGUI(wx.Frame): def __init__(self, title, size): wx.Frame.__init__(self, None, 1, title, size=size) # The GUI is made ... textbox.TextCtrl(panel1, 1, pos=(67,7), size=(150, 20)) button1.Bind(wx.EVT_BUTTON, self.button1Click) self.Show(True) def button1Click(self, event): #It needs to do the LoadThread function! class WebParser: def LoadThread(self, thread_id): #It needs to get the contents of textbox! TheGUI = TheGUI("Text RPG", (500,500)) TheParser = WebParser TheApp.MainLoop() So the problem i am having is that the GUI class needs to use a function that is in the WebParser class, and the WebParser class needs to get text from a textbox that exists in the GUI class. I know i could do this by passing the objects around as parameters, but that seems utterly pointless, there must be a more logical way to do this that doesn't using classes seem so pointless? Thanks in advance!

  Read the article

• Why should I prefer OSGi Services over exported packages?

  - by Jens

  Hi, I am trying to get my head around OSGi Services. The main question I keep asking myself is: What's the benefit of using services instead of working with bundles and their exported packages? As far as I know it seems the concept of Late Binding has something to do with it. Bundle dependencies are wired together at bundle start, so they are pretty fixed I guess. But with services it seems to be almost the same. A bundle starts and registers services or binds to services. Of course services can come and go whenever they want and you have to keep track of these chances. But the core idea doesn't seem that different to me. Another aspect to this seems to be that services are more flexible. There could be many implementations for one specific Interface. On the other hand there can be a lot of different implementations for a specific exported package too. In another text I read that the disadvantage of using exported packages is that they make the application more fragile than services. The author wrote that if you remove one bundle from the dependency graph other dependencies would no longer be met, thus possibly causing a domino effect on the whole graph. But couldn't the same happen if a service would go offline? To me it looks like service dependencies are no better than bundle dependencies. So far I could not find a blog post, book or presentation that could clearly describe why services are better than just exposing functionality by exporting and importing packages. To sum my questions up: What are the key benefits of using OSGi Services that make them superior to exporting and importing packages?

  Read the article

• Senior programming 'guru' who can't program - should I find a different career?

  - by confess

  Background: According to my resume I'm supposed to be pretty good at programming. I've worked on a ton of big projects at big companies over many years. When I go for an interview and someone looks at my resume they immediately assume I really know what I'm talking about. I generally communicate well, present myself well, know the 'jargon' and know a lot about technology at a high level, which makes matters worse because after talking to me for a while an interviewer really believes that what my resume says is probably true. The Problem: The problem arises when someone asks me to code something. I choke. As a programmer I have almost no capacity to come up with creative solutions of my own. I can't think through solutions to a programming problem the way good programmers are usually able to. I read questions on StackOverflow and the answer is obvious to me after I read other people's answers but if I am the first person to look at a question with no hints from anyone else I usually don't know where to start. At work it's the same thing. I'm fine if I'm correcting other people's code. I can identify the source of a bug quicker than anyone I work with. But if you ask me to sit down and code up a new application from scratch I will spend ten times longer than programmers who are much more junior than me. Question: Now that I am looking for work this is raising its ugly head in interview situations and making me feel desperately that I'm in the wrong career. I don't know if this problem is incompetence, laziness or some combination of these. Does anyone have any ideas about what I might be dealing with - are there books or exercises that could help me with this basic problem?

  Read the article

• Thread-Safe lazy instantiating using MEF

  - by Xaqron

  // Member Variable private static readonly object _syncLock = new object(); // Now inside a static method foreach (var lazyObject in plugins) { if ((string)lazyObject.Metadata["key"] = "something") { lock (_syncLock) { // It seems the `IsValueCreated` is not up-to-date if (!lazyObject.IsValueCreated) lazyObject.value.DoSomething(); } return lazyObject.value; } } Here I need synchronized access per loop. There are many threads iterating this loop and based on the key they are looking for, a lazy instance is created and returned. lazyObject should not be created more that one time. Although Lazy class is for doing so and despite of the used lock, under high threading I have more than one instance created (I track this with a Interlocked.Increment on a volatile static int and log it somewhere). The problem is I don't have access to definition of Lazy and MEF defines how the Lazy class create objects. I should notice the CompositionContainer has a thread-safe option in constructor which is already used. My questions: 1) Why the lock doesn't work ? 2) Should I use an array of locks instead of one lock for performance improvement ?

  Read the article

• Prevent coersion to a single type in unlist() or c(); passing arguments to wrapper functions

  - by Leo Alekseyev

  Is there a simple way to flatten a list while retaining the original types of list constituents?.. Is there a way to programmatically construct a heterogeneous list?.. For instance, I want to create a simple wrapper for functions like png(filename,width,height) that would take device name, file name, and a list of options. The naive approach would be something like my.wrapper <- function(dev,name,opts) { do.call(dev,c(filename=name,opts)) } or similar code with unlist(list(...)). This doesn't work because opts gets coerced to character, and the resulting call is e.g. png(filename,width="500",height="500"). If there's no straightforward way to create heterogeneous lists like that, is there a standard idiomatic way to splice arguments into functions without naming them explicitly (e.g. do.call(dev,list(filename=name,width=opts["width"]))? -- Edit -- Gavin Simpson answered both questions below in his discussion about constructing wrapper functions. Let me give a summary of the answer to the title question: It is possible to construct a heterogeneous list with c() provided the arguments to c() are lists. To wit: > foo <- c("a","b"); bar <- 1:3 > c(foo,bar) [1] "a" "b" "1" "2" "3" > c(list(foo),list(bar)) [[1]] [1] "a" "b" [[2]] [1] 1 2 3 > c(as.list(foo),as.list(bar)) ## this creates a flattened heterogeneous list [[1]] [1] "a" [[2]] [1] "b" [[3]] [1] 1 [[4]] [1] 2 [[5]] [1] 3

  Read the article

• Linq-to-sql join/where?

  - by Curtis White

  I've the following table structures Users id Types id isBool UsersTypes userid types I want to select all the UserTypes based on id and isBool. I tried this query var q = from usertype in usertypes from type in types where type.isBool == false where userstypes.user == id select usertype; But this did not work as expected. My questions are: Why? Is there any difference in using the join on syntax vs where, where vs where cond1 && cond2? My understanding is query optimizer will optimize. Is there any difference in using where cond1 == var1 && cond2 == var2 with and without the parenthesis? This seems peculiar that it is possible to build this without parenthesis What type of query do I need in this case? I can see that I could do a subquery or use a group but not 100% sure if it is required. An example might be helpful. I'm thinking a subquery may be required in this case.

  Read the article

• C function prototype: void f(). Is it recommended?

  - by ycalleecharan

  Hi, I'm learning C and I saw in a book that a function prototype has the form void f() and in the function declaration or in the calling function, the f function takes arguments. Thus In the function declaration we have something like void f(long double y[], long double A) and in the calling function is f(y, A). The function is doing operations on the array y i.e. when the function is called, some elements in the array y are changing. A is just a constant numerical value that doesn't change. I have two questions: If defining the function prototype at the top in the program as void f() a good practice? Or is it better to put it as void f(long double y[], long double A) as in the function declaration? The called function f is changing elements in the array y. Is void the right return type? The program is working fine as such with the void as described. Or should I change all my "voids" to "long double". I'm working with long double as I need as much precision as possible though on my machine both double and long double gives me 15 precision digits. Thanks a lot

  Read the article

• How to strongly type properties in JavaScript that map to models in C# ?

  - by Roberto Sebestyen

  I'm not even sure if I worded the question right, but I'll try and explain as clearly as possible with an example: In the following example scenario: 1) Take a class such as this: public class foo { public string firstName {get;set;} public string lastName {get;set} } 2) Serialize that into JSON, pass it over the wire to the Browser. 3) Browser de-serializes this and turns the JSON into a JavaScript object so that you can then access the properties like this: var foo = deSerialize("*******the JSON from above**************"); alert(foo.firstName); alert(foo.lastName); What if now a new developer comes along working on this project decides that firstName is no longer a suitable property name. Lets say they use ReSharper to rename this property, since ReSharper does a pretty good job at finding (almost) all the references to the property and renaming them appropriately. However ReSharper will not be able to rename the references within the JavaScript code (#3) since it has no way of knowing that these also really mean the same thing. Which means the programmer is left with the responsibility of manually finding these references and renaming those too. The risk is that if this is forgotten, no one will know about this error until someone tests that part of the code, or worse, slip through to the customer. Back to the actual question: I have been trying to think of a solution to this to some how strongly type these property names when used in javascript, so that a tool like ReSharper can successfully rename ALL usages of the property? Here is what I have been thinking for example (This would obviously not work unless i make some kind of static properties) var foo = deSerialize("*******the JSON from above**************"); alert(foo.<%=foo.firstName.GetPropertyName()%>) alert(foo.<%=foo.lastName.GetPropertyName()%>) But that is obviously not practical. Does anyone have any thoughts on this? Thanks, and kudos to all of the talented people answering questions on this site.

  Read the article

• Looking forward to a programming future but confused where to start.

  - by Kraivyne

  Hi there, I am very new to this site and to programming. I started doing some basic programming with python a few weeks ago and recently, messing around with Java basics. My main problem is that I am completely overwhelmed and haven't got the slightest clue where I should be starting. I want to learn programming because I really enjoy doing it, the simple applications that I have managed to conjure up put a smile on my face. My plan is to eventually (by eventually I'm talking about 6 years+) go into games programming. I have been informed that C++ is the best way to go about this but haven't got the slightest clue what book/sight is optimal for someone who is still learning the very basics. These are my questions: I have been to the Definitive C++ Book Guide but am still unsure which book is best to start of with. Should I stick with Python or Java instead of moving on to C++? Is there any advice you would give to a beginner programmer? Thanks again for all your help.

  Read the article

• Problem understanding Inheritance

  - by dhruvbird

  I've been racking my brains over inheritance for a while now, but am still not completely able to get around it. For example, the other day I was thinking about relating an Infallible Human and a Fallible Human. Let's first define the two: Infallible Human: A human that can never make a mistake. It's do_task() method will never throw an exception Fallible Human: A human that will occasionally make a mistakes. It's do_task() method may occasionally throw a ErrorProcessingRequest Exception The question was: IS an infallible human A fallible human OR IS a fallible human AN infallible human? The very nice answer I received was in the form of a question (I love these since it gives me rules to answer future questions I may have). "Can you pass an infallible human where a fallible human is expected OR can you pass a fallible human where an infallible human is expected?" It seems apparent that you can pass an infallible human where a fallible human is expected, but not the other way around. I guess that answered my question. However, it still feels funny saying "An infallible human is a fallible human". Does anyone else feel queasy when they say it? It almost feels as if speaking out inheritance trees is like reading out statements from propositional calculus in plain English (the if/then implication connectives don't mean the same as that in spoken English). Does anyone else feel the same?

  Read the article

• Django: getting the list of related records for a list of objects

  - by Silver Light

  Hello! I have two models related one-to many: class Person(models.Model): name = models.CharField(max_length=255); surname = models.CharField(max_length=255); age = models.IntegerField(); class Dog(models.Model): name = models.CharField(max_length=255); owner = models.ForeignKey('Person'); I want to output a list of persons below each person a list of dogs he has. Here's how I can do it: in view: persons = Person.objects.all()[0:100]; in template: {% for p in persons %} {{ p.name }} has dogs:<br /> {% for d in persons.dog_set.all %} - {{ d.name }}<br /> {% endfor %} {% endfor %} But if I do it like that, Django will execute 101 SQL queries which is very inefficient. I tried to make a custom manager, which will get all the persons, then all the dogs and links them in python, but then I can't use paginator (my another question: http://stackoverflow.com/questions/2532475/django-paginator-raw-sql-query ) and it looks quite ugly. Is there a more graceful way doing this?

  Read the article

• Context path routing in Tomcat ( service swapping )

  - by jojovilco

  Here is what I would like to achieve: I have a web service A which I want to be able to deploy side by side with other web services of type A - different version(s). For now I assume 2 instances side by side. I need it because the service has a warm up stage, which takes some time to build up stuff from DB and only after it is ready it can start serving requests ... I was thinking to deploy to Tomcat context paths like: "/ServiceA-1.0", "/ServiceA-2.0" and then have a "virtual" context like "/ServiceA" which will point to the desired physical service e.g. "/ServiceA-1.0". So external world will know about ServiceA, but internally, my ServiceA related stack would know about versioned ServiceA url ( there are more components involved but only ServiceA is serving outer world ). When new service is ready, I would just reconfigure the "virtual" context to point to a new service. So far, I was not able to find out how to do this with Tomcat and starting to tkink it is not possible. I found suggestions to place Apache Server in front of Tomcat and do the routing there, but I do not want to enroll another piece of software unless necessary. My questions are: - is this kind of a "virtual" context and routing possible to do with Tomcat? - any other options, wisdom and lessons learned how to achieve this kind of service swapping scenario? Best, Jozef

  Read the article

• Why is function's length information of other shared lib in ELF?

  - by minastaros

  Our project (C++, Linux, gcc, PowerPC) consists of several shared libraries. When releasing a new version of the package, only those libs should change whose source code was actually affected. With "change" I mean absolute binary identity (the checksum over the file is compared. Different checksum - different version according to the policy). (I should mention that the whole project is always built at once, no matter if any code has changed or not per library). Usually this can by achieved by hiding private parts of the included Header files and not changing the public ones. However, there was a case where just a delete was added to the destructor of a class TableManager (in the TableManager.cpp file!) of library libTableManager.so, and yet the binary/checksum of library libB.so (which uses class TableManager ) has changed. TableManager.h: class TableManager { public: TableManager(); ~TableManager(); private: int* myPtr; } TableManager.cpp: TableManager::~TableManager() { doSomeCleanup(); delete myPtr; // this delete has been added } By inspecting libB.so with readelf --all libB.so, looking at the .dynsym section, it turned out that the length of all functions, even the dynamically used ones from other libraries, are stored in libB! It looks like this (length is the 668 in the 3rd column): 527: 00000000 668 FUNC GLOBAL DEFAULT UND _ZN12TableManagerD1Ev So my questions are: Why is the length of a function actually stored in the client lib? Wouldn't a start address be sufficient? Can this be suppressed somehow when compiling/linking of libB.so (kind of "stripping")? We would really like to reduce this degree of dependency...

  Read the article

< Previous Page | 498 499 500 501 502 503 504 505 506 507 508 509  | Next Page >