Search Results

Search found 6086 results on 244 pages for 'book recommendation'.

Page 220/244 | < Previous Page | 216 217 218 219 220 221 222 223 224 225 226 227  | Next Page >

  • csrf error in django

    - by niklasfi
    Hello, I want to realize a login for my site. I basically copied and pasted the following bits from the Django Book together. However I still get an error (CSRF verification failed. Request aborted.), when submitting my registration form. Can somebody tell my what raised this error and how to fix it? Here is my code: views.py: # Create your views here. from django import forms from django.contrib.auth.forms import UserCreationForm from django.http import HttpResponseRedirect from django.shortcuts import render_to_response def register(request): if request.method == 'POST': form = UserCreationForm(request.POST) if form.is_valid(): new_user = form.save() return HttpResponseRedirect("/books/") else: form = UserCreationForm() return render_to_response("registration/register.html", { 'form': form, }) register.html: <html> <body> {% block title %}Create an account{% endblock %} {% block content %} <h1>Create an account</h1> <form action="" method="post">{% csrf_token %} {{ form.as_p }} <input type="submit" value="Create the account"> </form> {% endblock %} </body> </html>

    Read the article

  • Why is debugging better in an IDE?

    - by Bill Karwin
    I've been a software developer for over twenty years, programming in C, Perl, SQL, Java, PHP, JavaScript, and recently Python. I've never had a problem I could not debug using some careful thought, and well-placed debugging print statements. I respect that many people say that my techniques are primitive, and using a real debugger in an IDE is much better. Yet from my observation, IDE users don't appear to debug faster or more successfully than I can, using my stone knives and bear skins. I'm sincerely open to learning the right tools, I've just never been shown a compelling advantage to using visual debuggers. Moreover, I have never read a tutorial or book that showed how to debug effectively using an IDE, beyond the basics of how to set breakpoints and display the contents of variables. What am I missing? What makes IDE debugging tools so much more effective than thoughtful use of diagnostic print statements? Can you suggest resources (tutorials, books, screencasts) that show the finer techniques of IDE debugging? Sweet answers! Thanks much to everyone for taking the time. Very illuminating. I voted up many, and voted none down. Some notable points: Debuggers can help me do ad hoc inspection or alteration of variables, code, or any other aspect of the runtime environment, whereas manual debugging requires me to stop, edit, and re-execute the application (possibly requiring recompilation). Debuggers can attach to a running process or use a crash dump, whereas with manual debugging, "steps to reproduce" a defect are necessary. Debuggers can display complex data structures, multi-threaded environments, or full runtime stacks easily and in a more readable manner. Debuggers offer many ways to reduce the time and repetitive work to do almost any debugging tasks. Visual debuggers and console debuggers are both useful, and have many features in common. A visual debugger integrated into an IDE also gives you convenient access to smart editing and all the other features of the IDE, in a single integrated development environment (hence the name).

    Read the article

  • How to install Zend Framework on Windows

    - by sombe
    "installing Zend Framework is so easy!!!!" yeah right... Ok I'm working with a beginner's book and the ONE thing that is not excessively detailed is the most important part: Installing the darn thing. After browsing the quickstart guide for hours, all it said was: "download Zend [...] add the include directory (bla bla) and YOU'RE DONE!" right, i'm done using Zend. Ok, not really, not yet anyway. I beg of you people, I wanna go to bed, please tell me how (in simple 6th grade detail) to install the framework. I've got the unzipped folder in my htdocs directory, and I placed zf.bat+zf.php in the htdocs root. What's next? thank you so much. EDIT: Thanks guys for all the answers. Unfortunately I haven't been able to work with this or find a good enough resource to explain it to me in plain english. It seems that this framework adheres more so to programmers than to beginners. I've since yesterday read a little on CakePHP and found that it was incredibly easy to install and tune. As oppose to Zend Framework, where I had to dig in my "environment variables", configure "httpd.conf" and almost tie the knot between my computer driver cables to just get it running, CakePHP has already allowed me to put together a nice newbie application. In conclusion, I very much appreciate all of your help. I hope someone else venturing on ZF will be more successful with it. Thanks!

    Read the article

  • django simple approach to multi-field search

    - by Scott Willman
    I have a simple address book app that I want to make searchable. The model would look something like: class Address(models.Model): address1 = models.CharField("Address Line 1", max_length=128) address2 = models.CharField("Address Line 2", max_length=128) city = models.CharField("City", max_length=128) state = models.CharField("State", max_length=24) zipCode = models.CharField("Zip Code", max_length=24) def __unicode__(self): return "%s %s, %s, %s, %s" % (self.address1, self.address2, self.city, self.state, self.zipCode) class Entry(models.Model): name = models.CharField("Official School Name", max_length=128) createdBy = models.ForeignKey(User) address = models.ForeignKey(Address, unique=True) def __unicode__(self): return "%s - %s, %s" % (self.name, self.address.city, self.address.state) I want the searching to be fairly loose, like: Bank of America Los Angeles 91345. It seems like I want a field that contains all of those elements into one that I can search, but that also seems redundant. I was hoping I could add a method to the Entry model like this: def _getSearchText(self): return "%s %s %s" % (self.name, self.address, self.mascot) searchText = property(_getSearchText) ...and search that as a field, but I suppose that's wishful thinking... How should I approach this using basic Django and SqLite (this is a learning exercise). Thank you!!

    Read the article

  • Where can a self-teacher learn general good programming habits and conventions?

    - by lucid
    A few mistakes and general childishness in early adulthood have left me in a situation where I work a menial job, with no possibility (in the near future) of attending school. I aspire to one day work in the programming field (gaming specifically), after proving myself on the indie end of things. I've gotten very confident in C++, java, and python, and I find I'm able to solve any problem I want either from previous experience, or from scouring the web for help. The solutions work, and with each attempt they become more readable, maintainable, and extensible. But this is because I'm learning from mistakes and bad programming and design habits I feel I might have avoided with actual schooling. General tips like: "if it's hard to read or getting long, or you're writing it twice, it should be in one or more functions." or "design all your classes before you start coding, so you don't have to rewrite classes later when you discover an unforeseen dependency" Is there a good book or website for learning general good programming practices and design habits? Also, naming and format conventions. I realize sometimes development houses have their own conventions, but things like "Classes in python usually have the first letter of each word capitalized". I'd like to be able to show some source code to a potential employer, and be prepared when for what's expected on a team. Is there some central database of naming and formatting conventions somewhere? Also, feel free to give any thoughts on whether or not the self-teach, garner some indie sales, use them as your resume' route is realistic

    Read the article

  • Can this extension method be improved?

    - by Newbie
    I have the following extension method public static class ListExtensions { public static IEnumerable<T> Search<T>(this ICollection<T> collection, string stringToSearch) { foreach (T t in collection) { Type k = t.GetType(); PropertyInfo pi = k.GetProperty("Name"); if (pi.GetValue(t, null).Equals(stringToSearch)) { yield return t; } } } } What it does is by using reflection, it finds the name property and then filteres the record from the collection based on the matching string. This method is being called as List<FactorClass> listFC = new List<FactorClass>(); listFC.Add(new FactorClass { Name = "BKP", FactorValue="Book to price",IsGlobal =false }); listFC.Add(new FactorClass { Name = "YLD", FactorValue = "Dividend yield", IsGlobal = false }); listFC.Add(new FactorClass { Name = "EPM", FactorValue = "emp", IsGlobal = false }); listFC.Add(new FactorClass { Name = "SE", FactorValue = "something else", IsGlobal = false }); List<FactorClass> listFC1 = listFC.Search("BKP").ToList(); It is working fine. But a closer look into the extension method will reveal that Type k = t.GetType(); PropertyInfo pi = k.GetProperty("Name"); is actually inside a foreach loop which is actually not needed. I think we can take it outside the loop. But how? PLease help. (C#3.0)

    Read the article

  • How would you implement a hashtable in language x?

    - by mk
    The point of this question is to collect a list of examples of hashtable implementations using arrays in different languages. It would also be nice if someone could throw in a pretty detailed overview of how they work, and what is happening with each example. Edit: Why not just use the built in hash functions in your specific language? Because we should know how hash tables work and be able to implement them. This may not seem like a super important topic, but knowing how one of the most used data structures works seems pretty important to me. If this is to become the wikipedia of programming, then these are some of the types of questions that I will come here for. I'm not looking for a CS book to be written here. I could go pull Intro to Algorithms off the shelf and read up on the chapter on hash tables and get that type of info. More specifically what I am looking for are code examples. Not only for me in particular, but also for others who would maybe one day be searching for similar info and stumble across this page. To be more specific: If you had to implement them, and could not use built-in functions, how would you do it? You don't need to put the code here. Put it in pastebin and just link it.

    Read the article

  • php and mysql listing databases and looping through results

    - by Jacksta
    Beginner help needed :) I am doign an example form a php book which lists tables in databases. I am getting an error on line 36: $db_list .= "$table_list"; <?php //connect to database $connection = mysql_connect("localhost", "admin_cantsayno", "cantsayno") or die(mysql_error()); //list databases $dbs = @mysql_list_dbs($connection) or die(mysql_error()); //start first bullet list $db_list = "<ul>"; $db_num = 0; //loop through results of functions while ($db_num < mysql_num_rows($dbs)) { //get database names and make each a list point $db_names[$db_num] = mysql_tablename($dbs, $db_num); $db_list .= "<li>$db_names[$db_num]"; //get table names and make another list $tables = @mysql_list_tables($db_names[$db_num]) or die(mysql_error()); $table_list = "<ul>"; $table_num = 0; //loop through results of function while ($table_num < mysql_num_rows($tables)){ //get table names and make each bullet point $table_names[$table_num] = mysql_tablename($tables, $table_num); $table_list .= "<li>$table_names[$table_num]"; $table_num++; } //close inner bullet list and increment number to continue $table_list .= "</ul>" $db_list .= "$table_list"; $db_num++; } //close outer bullet list $db_list .= "</ul>"; ?> <html> <head> <title>MySQL Tables</title> </head> <body> <p><strong>Data bases and tables on local host</strong></p> <? echo "$db_list"; ?> </body>

    Read the article

  • When is factory method better than simple factory and vice versa?

    - by Bruce
    Hi all Working my way through the Head First Design Patterns book. I believe I understand the simple factory and the factory method, but I'm having trouble seeing what advantages factory method brings over simple factory. If an object A uses a simple factory to create its B objects, then clients can create it like this: A a = new A(new BFactory()); whereas if an object uses a factory method, a client can create it like this: A a = new ConcreteA(); // ConcreteA contains a method for instantiating the same Bs that the BFactory above creates, with the method hardwired into the subclass of A, ConcreteA. So in the case of the simple factory, clients compose A with a B factory, whereas with the factory method, the client chooses the appropriate subclass for the types of B it wants. There really doesn't seem to be much to choose between them. Either you have to choose which BFactory you want to compose A with, or you have to choose the right subclass of A to give you the Bs. Under what circumstances is one better than the other? Thanks all!

    Read the article

  • Data encapsulation in Swift

    - by zpasternack
    I've read the entire Swift book, and watched all the WWDC videos (all of which I heartily recommend). One thing I'm worried about is data encapsulation. Consider the following (entirely contrived) example: class Stack<T> { var items : T[] = [] func push( newItem: T ) { items.insert( newItem, atIndex: 0 ) } func pop() -> T? { if items.count == 0 { return nil; } return items.removeAtIndex( 0 ); } } This class implements a stack, and implements it using an Array. Problem is, items (like all properties in Swift) is public, so nothing is preventing anyone from directly accessing (or even mutating) it separate from the public API. As a curmudgeonly old C++ guy, this makes me very grumpy. I see people bemoaning the lack of access modifiers, and while I agree they would directly address the issue (and I hear rumors that they might be implemented Soon (TM) ), I wonder what some strategies for data hiding would be in their absence. Have I missed something, or is this simply an omission in the language?

    Read the article

  • Invalid controller using custom routes

    - by AlexW
    I've been following the instruction on how to create custom routes from the book Zend Framework - A Beginners Guide I've changed my application.ini file to include this routing information: resources.router.routes.static-content.route = /content/:page resources.router.routes.static-content.defaults.module = default resources.router.routes.static-content.defaults.controller = static-content resources.router.routes.static-content.defaults.view = static-content resources.router.routes.static-content.defaults.action = display Given the above configuration, I have this controller: <?php class Default_StaticContentController extends Zend_Controller_Action { public function init() { /* Initialize action controller here */ } public function displayAction() { // action body $page = $this->getRequest()->getParam('page'); if (file_exists($this->view->getScriptPath(null) . '/' . $this->getRequest()->getControllerName() . '/' . $page . $this->viewSuffix )) { $this->render($page); } else { throw new Zend_Controller_Action_Exception('HLC - Page not found', 404); } } } I have a view named about.phtml in the APPLICATION_PATH/modules/default/views/static-content folder. What ahppens is I get an error saying: An error occurred Page not found Exception information: Message: Invalid controller class ("StaticContentController") Stack trace: #0 /Applications/MAMP/htdocs/zend/library/Zend/Controller/Dispatcher/Standard.php(262): Zend_Controller_Dispatcher_Standard->loadClass('StaticContentCo...') #1 /Applications/MAMP/htdocs/zend/library/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #2 /Applications/MAMP/htdocs/zend/library/Zend/Application/Bootstrap/Bootstrap.php(97): Zend_Controller_Front->dispatch() #3 /Applications/MAMP/htdocs/zend/library/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run() #4 /Applications/MAMP/htdocs/HLC/public/index.php(26): Zend_Application->run() #5 {main} Request Parameters: array ( 'page' => 'about', 'module' => 'default', 'controller' => 'static-content', 'view' => 'static-content', 'action' => 'display', ) Note that it is not rendering my customised Zend_Controller_Action_Exception but throwing the global error. I'm using the URL: http://hlc.local:8888/content/about The default index action works ok, just this routing that's not working.

    Read the article

  • barebones sort algorithm

    - by user309322
    i have been asked to make a simple sort aglorithm to sort a random series of 6 numbers into numerical order. However i have been asked to do this using "Barebones" a theoretical language put forward in the Book Computer Science an overview. Some information on the language can be found here http://www.brouhaha.com/~eric/software/barebones/ Just to clarify i am a student teacher and have been doing anaysis on "mini-programing languages" and their uses in a teaching environment, i suggested to my tutor that i look at barebones and asked what sort of exmaple program i should write . He suggested a simple sort algorithm. Now since looking at the language i cant understand how i can do this without using arrays and if statements. The code to swap the value of variables would be while a not 0 do; incr Aux1; decr a; end; while b not 0 do; incr Aux2 decr b end; while Aux1 not 0 do; incr a; decr Aux1; end; while Aux2 not 0 do; incr b; decr Aux2; end; however the language does not provide < or operators

    Read the article

  • how to change ASP.NET Configuration tool connection string

    - by Zviadi
    Hello, how can I change ASP.NET Configuration tool-s connection string name? (Which connection string will ASP.NET Configuration tool will use) I'm learning ASP.NET and everywhere and in book that I'm reading now theres connection string named: LocalSqlServer. I want to use my local sql server database instead of sql express to store Roles, Membership and other data. I have used aspnet_regsql.exe to create needed data structures in my database. after that I changed my web.config to look like: <connectionStrings> <remove name="LocalSqlServer"/> <add name="LocalSqlServer" connectionString="Server=(LOCAL); Database=MyDatabase;Integrated Security=True" providerName="System.Data.SqlClient" /> </connectionStrings> but when I run ASP.NET Configuration tool it says that: "The connection name 'ApplicationServices' was not found in the applications configuration or the connection string is empty." ASP.NET Configuration tool uses connection string named: ApplicationServices not LocalSqlServer. cause of that I have to modify web.config to: <connectionStrings> <add name="ApplicationServices" connectionString="Server=(LOCAL); Database=MyDatabase;Integrated Security=True" providerName="System.Data.SqlClient" /> </connectionStrings> and everything works fine. I wish to know why the hell my web site uses connection string named: ApplicationServices and all books and online documentations uses LocalSqlServer? and how to change it to LocalSqlServer? I have: Windows 7 Sql Server 2008 R2 Visual Studio 2010 Premium Project type is website

    Read the article

  • Ruby and public_method_defined? : strange behaviour

    - by aXon
    Hi there Whilst reading through the book "The well grounded Rubyist", I came across some strange behaviour. The idea behind the code is using one's own method_missing method. The only thing I am not able to grasp is, why this code gets executed, as I do not have any Person.all_with_* class methods defined, which in turn means that the self.public_method_defined?(attr) returns true (attr is friends and then hobbies). #!/usr/bin/env ruby1.9 class Person PEOPLE = [] attr_reader :name, :hobbies, :friends def initialize(mame) @name = name @hobbies = [] @friends = [] PEOPLE << self end def has_hobby(hobby) @hobbies << hobby end def has_friend(friend) @friends << friend end def self.method_missing(m,*args) method = m.to_s if method.start_with?("all_with_") attr = method[9..-1] if self.public_method_defined?(attr) PEOPLE.find_all do |person| person.send(attr).include?(args[0]) end else raise ArgumentError, "Can't find #{attr}" end else super end end end j = Person.new("John") p = Person.new("Paul") g = Person.new("George") r = Person.new("Ringo") j.has_friend(p) j.has_friend(g) g.has_friend(p) r.has_hobby("rings") Person.all_with_friends(p).each do |person| puts "#{person.name} is friends with #{p.name}" end Person.all_with_hobbies("rings").each do |person| puts "#{person.name} is into rings" end The output is is friends with is friends with is into rings which is really understandable, as there is nothing to be executed.

    Read the article

  • Parse a CSV file using python (to make a decision tree later)

    - by Margaret
    First off, full disclosure: This is going towards a uni assignment, so I don't want to receive code. :). I'm more looking for approaches; I'm very new to python, having read a book but not yet written any code. The entire task is to import the contents of a CSV file, create a decision tree from the contents of the CSV file (using the ID3 algorithm), and then parse a second CSV file to run against the tree. There's a big (understandable) preference to have it capable of dealing with different CSV files (I asked if we were allowed to hard code the column names, mostly to eliminate it as a possibility, and the answer was no). The CSV files are in a fairly standard format; the header row is marked with a # then the column names are displayed, and every row after that is a simple series of values. Example: # Column1, Column2, Column3, Column4 Value01, Value02, Value03, Value04 Value11, Value12, Value13, Value14 At the moment, I'm trying to work out the first part: parsing the CSV. To make the decisions for the decision tree, a dictionary structure seems like it's going to be the most logical; so I was thinking of doing something along these lines: Read in each line, character by character If the character is not a comma or a space Append character to temporary string If the character is a comma Append the temporary string to a list Empty string Once a line has been read Create a dictionary using the header row as the key (somehow!) Append that dictionary to a list However, if I do things that way, I'm not sure how to make a mapping between the keys and the values. I'm also wondering whether there is some way to perform an action on every dictionary in a list, since I'll need to be doing things to the effect of "Everyone return their values for columns Column1 and Column4, so I can count up who has what!" - I assume that there is some mechanism, but I don't think I know how to do it. Is a dictionary the best way to do it? Would I be better off doing things using some other data structure? If so, what?

    Read the article

  • Why does C# not provide the C++ style 'friend' keyword?

    - by Ash
    The C++ friend keyword allows a class A to designate class B as it's friend. This allows Class B to access the private/protected members of class A. I've never read anything as to why this was left out of C# (and VB.NET). Most answers to this earlier StackOverflow question seem to be saying it is a useful part of C++ and there are good reasons to use it. In my experience I'd have to agree. Another question seems to me to be really asking how to do something similar to friend in a C# application. While the answers generally revolve around nested classes, it doesn't seem quite as elegant as using the friend keyword. The original Design Patterns book uses the friend keyword regularly throughout its examples. So in summary, why is friend missing from C#, and what is the "best practice" way (or ways) of simulating it in C#? (By the way, the "internal" keyword is not the same thing, it allows ALL classes within the entire assembly to access internal members, friend allows you to give access to a class to just one other class.)

    Read the article

  • need help with Java solution /newbie

    - by Racket
    Hi, I'm new to programming in general so i'm trying to be as specific as possible in this question. There's this book that i'm doing some exercises on. I managed to do more than half of what they say, but it's just one input that I have been struggling to find out. I'll write the question and thereafter my code, "Write an application that creates and prints a random phone number of the form XXX-XXX-XXXX. Include the dashes in the output. Do not let the first three digits contain an 8 or 9 (but don't be more restrictive than that), and make sure that the second set of three digits is not greater than 742. Hint: Think through the easiest way to construct the phone number. Each diigit does not have to be determined separately." OK, the highlighted sentence is what i'm looking at. Here's my code: import java.util.Random; public class PP33 { public static void main (String[] args) { Random rand = new Random(); int num1, num2, num3; num1 = rand.nextInt(900) + 100; num2 = rand.nextInt(643) + 100; num3 = rand.nextInt(9000) + 1000; System.out.println(num1+"-"+num2+"-"+num3); } } How am I suppose to do this? I'm on chapter 3 so we have not yet discussed if statements etcetera, but Aliases, String class, Packages, Import declaration, Random Class, Math Class, Formatting output (decimal- & numberFormat), Printf, Enumeration & Wrapper classes + autoboxing. So consider answer the question based only on these assumptions, please. The code doesn't have any errors. Thank you!

    Read the article

  • how to check null value of Integer type field in ASP.NET MVC view?

    - by Vikas
    Hi, I have integer type field in database which is having property "Not Null". when i create a view & do a validation, if i left that field blank, it will consider it as 0 so i can not compare it with 0 because if someone insert a value 0 then it will be considered as error! one another problem is that i am using Model error as described in the book "ASP.NET MVC 1.0" @ Scott Gu blog. And I am checking the value in partial class of object (created by LINQ-To-SQL). i.e public partial class Person { public bool IsValid { get { return (GetRuleViolations().Count() == 0); } } public IEnumerable<RuleViolation> GetRuleViolations() { if (String.IsNullOrEmpty(Name)) yield return new RuleViolation("Name is Required", "Name"); if (Age == 0) yield return new RuleViolation("Age is Required", "Age"); yield break; } partial void OnValidate(ChangeAction action) { if (!IsValid) throw new ApplicationException("Rule violations prevent saving"); } } There is also problem with range. Like in database if i declared as smallint i.e. short in c#, now if i exceed that range then it gives error as "A Value is reguired". so finally is there any best way for validation in ASP.NET MVC?

    Read the article

  • How should rules for Aggregate Roots be enforced?

    - by MylesRip
    While searching the web, I came across a list of rules from Eric Evans' book that should be enforced for aggregates: The root Entity has global identity and is ultimately responsible for checking invariants Root Entities have global identity. Entities inside the boundary have local identity, unique only within the Aggregate. Nothing outside the Aggregate boundary can hold a reference to anything inside, except to the root Entity. The root Entity can hand references to the internal Entities to other objects, but they can only use them transiently (within a single method or block). Only Aggregate Roots can be obtained directly with database queries. Everything else must be done through traversal. Objects within the Aggregate can hold references to other Aggregate roots. A delete operation must remove everything within the Aggregate boundary all at once When a change to any object within the Aggregate boundary is committed, all invariants of the whole Aggregate must be satisfied. This all seems fine in theory, but I don't see how these rules would be enforced in the real world. Take rule 3 for example. Once the root entity has given an exteral object a reference to an internal entity, what's to keep that external object from holding on to the reference beyond the single method or block? (If the enforcement of this is platform-specific, I would be interested in knowing how this would be enforced within a C#/.NET/NHibernate environment.)

    Read the article

  • Object equality in context of hibernate / webapp

    - by bert
    How do you handle object equality for java objects managed by hibernate? In the 'hibernate in action' book they say that one should favor business keys over surrogate keys. Most of the time, i do not have a business key. Think of addresses mapped to a person. The addresses are keeped in a Set and displayed in a Wicket RefreshingView (with a ReuseIfEquals strategy). I could either use the surrogate id or use all fields in the equals() and hashCode() functions. The problem is that those fields change during the lifetime ob the object. Either because the user entered some data or the id changes due to JPA merge() being called inside the OSIV (Open Session in View) filter. My understanding of the equals() and hashCode() contract is that those should not change during the lifetime of an object. What i have tried so far: equals() based on hashCode() which uses the database id (or super.hashCode() if id is null). Problem: new addresses start with an null id but get an id when attached to a person and this person gets merged() (re-attached) in the osiv-filter. lazy compute the hashcode when hashCode() is first called and make that hashcode @Transitional. Does not work, as merge() returns a new object and the hashcode does not get copied over. What i would need is an ID that gets assigned during object creation I think. What would be my options here? I don't want to introduce some additional persistent property. Is there a way to explicitly tell JPA to assign an ID to an object? Regards

    Read the article

  • MySQL get point in time totals from related tables

    - by batfastad
    Hi everyone We have an order book and invoicing system and I've been tasked with trying to output monthly rolling totals from these tables. But I don't know really where to start with this. I think there's some SQL syntax that I don't even know about yet. I'm familiar with INNER/LEFT/JOINS and GROUP BY etc but grouping by date is confusing since I don't know how to limit the data to only the current date that's being grouped by at that point. I think this will involve joining the tables to themselves or possibly a sub-select. I always thought it best to avoid sub-selects apart from when absolutely necessary. Basically the system has 3 tables orders: order_id, currency, order_stamp orders_lines: order_line_id, invoice_id, order_id, price invoices: invoice_id, invoice_stamp order_stamp and invoice_stamp are UTC unix timestamps stored as integers, not MySQL timestamps. I'm trying to get a listing by year/month showing the total of current unbilled orders (sum of price), at that point in time. Current orders are ones where order_stamp is less than or equal to 00:00 on the 1st of the month. Unbilled orders are ones where invoice_stamp is null or invoice_stamp is greater than 00:00 on the 1st of the month. At that point in time there may not be a related invoice yet and invoice_id might be null. Anyone got any suggestions on what I should join to what and what I need to group by? Cheers, B

    Read the article

  • Java Concurrency in practice sample question

    - by andy boot
    I am reading "Java Concurrency in practice" and looking at the example code on page 51. This states that if a thread has references to a shared object then other threads may be able to access that object before the constructor has finished executing. I have tried to put this into practice and so I wrote this code thinking that if I ran it enough times a RuntimeException("World is f*cked") would occur. But it isn't doing. Is this a case of the Java spec not guaranting something but my particular implementation of java guaranteeing it for me? (java version: 1.5.0 on Ubuntu) Or have I misread something in the book? Code: (I expect an exception but it is never thrown) public class Threads { private Widgit w; public static void main(String[] s) throws Exception { while(true){ Threads t = new Threads(); t.runThreads(); } } private void runThreads() throws Exception{ new Checker().start(); w = new Widgit((int)(Math.random() * 100) + 1); } private class Checker extends Thread{ private static final int LOOP_TIMES = 1000; public void run() { int count = 0; for(int i = 0; i < LOOP_TIMES; i++){ try { w.checkMe(); count++; } catch(NullPointerException npe){ //ignore } } System.out.println("checked: "+count+" times out of "+LOOP_TIMES); } } private static class Widgit{ private int n; private int n2; Widgit(int n) throws InterruptedException{ this.n = n; Thread.sleep(2); this.n2 = n; } void checkMe(){ if (n != n2) { throw new RuntimeException("World is f*cked"); } } } }

    Read the article

  • Looking for a RESTful or SOAP pipeline between WordPress and InterWoven TeamSite

    - by deanpeters
    I've been Googling my brains out trying see if there's a simple way to bridge content to and from WordPress to and from TeamSite. I'm coming at this from the perspective of a WordPress developer. I see in the book "The Definitive Guide to Interwoven TeamSite" (http://bit.ly/d3z4wI) mention of objects for the Interwoven LiveSite product: com.interwoven.livesite.external.impl.RSS com.interwoven.livesite.external.impl.SOAP If I understand the above objects correctly, these allow me to instantiate objects of these data types, which after populating them via various method calls, allow me to render content using com.interwoven.livesite.external.ExternalCall ... but I'm not sure. Nor do I think this approach provides me the 2-way street I seek. As it stands now, from my limited understanding, it appears that the least path of resistance is deploying Interwoven's LiveSite with the existing TeamSite implementation so content can be both consumed and rendered via RSS ... an channel which WordPress can produce and consume; the latter with plugins such as wp-o-matic and/or feedpress. So the question is, does anyone out there have experience with a SOAP or RESTful API approach to InterWoven's TeamSite? If so, can I get some direction on documentation? Or is the addition of LiveSite + RSS the most feasible 2-way channel?

    Read the article

  • Why does grails use hsqldb when I ask for mysql?

    - by John
    I'm following the racetrack example from Jason Rudolph's book at InfoQ, using grails-1.2.1. I got up to the part where I was to switch from hsqldb to mysql. I think I've deleted every reference to hsqldb in the DataSource.groovy file, but I get an exception and the stack trace shows it's still using hsqldb. DataSource.groovy dataSource { boolean pooled = true String driverClassName = "com.mysql.jdbc.Driver" String url = "jdbc:mysql://localhost/dfpc2" String dbCreate = "create" String username = "dfpc2" String password = "dfpc2" dialect = org.hibernate.dialect.MySQL5InnoDBDialect } hibernate { cache.use_second_level_cache=true cache.use_query_cache=true cache.provider_class='net.sf.ehcache.hibernate.EhCacheProvider' } // environment specific settings environments { development { } test { } production { } } When I grails run-app it all starts up with no errors. I can navigate to the home page. But when I click on one of the links, I get a stack trace: java.sql.SQLException: Table not found in statement [select this_.id as id0_0_, this_.version as version0_0_, this_.name as name0_0_, this_.variant as variant0_0_ from domainObject this_ limit ?] at org.hsqldb.jdbc.Util.throwError(Unknown Source) at org.hsqldb.jdbc.jdbcPreparedStatement.<init>(Unknown Source) at org.hsqldb.jdbc.jdbcConnection.prepareStatement(Unknown Source) at dfpc2.domainObjectController$_closure2.doCall(script1269434425504953491149.groovy:13) at dfpc2.domainObjectController$_closure2.doCall(script1269434425504953491149.groovy) at java.lang.Thread.run(Thread.java:619) My mysql database shows no tables created. (I don't think groovy's connected to mysql yet.) Things I've checked: mysql-connector-java-5.1.6.jar is in lib directory. I've tried grails clean I tried putting the dataSource info in the development environment (I haven't graduated to test or prod yet), but it seemed to make no difference. The stdout shows I'm using development env. I've googled for solutions, but the only solution I've found is when people don't change the test or production environments.

    Read the article

  • Haskell Cons Operator (:)

    - by Carson Myers
    I am really new to Haskell (Actually I saw "Real World Haskell" from O'Reilly and thought "hmm, I think I'll learn functional programming" yesterday) and I am wondering: I can use the construct operator to add an item to the beginning of a list: 1 : [2,3] [1,2,3] I tried making an example data type I found in the book and then playing with it: --in a file data BillingInfo = CreditCard Int String String | CashOnDelivery | Invoice Int deriving (Show) --in ghci $ let order_list = [Invoice 2345] $ order_list [Invoice 2345] $ let order_list = CashOnDelivery : order_list $ order_list [CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, CashOnDelivery, ...- etc... it just repeats forever, is this because it uses lazy evaluation? -- EDIT -- okay, so it is being pounded into my head that let order_list = CashOnDelivery:order_list doesn't add CashOnDelivery to the original order_list and then set the result to order_list, but instead is recursive and creates an infinite list, forever adding CashOnDelivery to the beginning of itself. Of course now I remember that Haskell is a functional language and I can't change the value of the original order_list, so what should I do for a simple "tack this on to the end (or beginning, whatever) of this list?" Make a function which takes a list and BillingInfo as arguments, and then return a list? -- EDIT 2 -- well, based on all the answers I'm getting and the lack of being able to pass an object by reference and mutate variables (such as I'm used to)... I think that I have just asked this question prematurely and that I really need to delve further into the functional paradigm before I can expect to really understand the answers to my questions... I guess what i was looking for was how to write a function or something, taking a list and an item, and returning a list under the same name so the function could be called more than once, without changing the name every time (as if it was actually a program which would add actual orders to an order list, and the user wouldn't have to think of a new name for the list each time, but rather append an item to the same list).

    Read the article

< Previous Page | 216 217 218 219 220 221 222 223 224 225 226 227  | Next Page >