Search Results

Search found 4969 results on 199 pages for 'def'.

Page 67/199 | < Previous Page | 63 64 65 66 67 68 69 70 71 72 73 74  | Next Page >

  • Grails Duplicate Exception handling

    - by Srinath
    Hi, How to catch duplicate key exceptions in Grails . when trying to save existing integer for a unique column constraint, the error is generating while saving/updating a record . Also used try{ object.save(flush:true) }catch(org.springframework. dao.DataIntegrityViolationException e){ println e.message }catch(org.hibernate.exception.ConstraintViolationException ex){ println e.message }catch(Exception e){ println e.message } But unable to catch this issue . 23:41:13,265 ERROR [JDBCExceptionReporter:101] Duplicate entry '1' for key 2 23:41:13,281 ERROR [AbstractFlushingEventListener:324] Could not synchronize database state with session org.hibernate.exception.ConstraintViolationException: Could not execute JDBC batch update at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:94) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66) at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:275) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:266) at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:168) at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321) at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:50) at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1027) Could you please share the solution to solve this .

    Read the article

  • Use eval to set unknown property in Python

    - by Mahi
    I have an User class, that has multiple properties inside it, and I also have addPoint method for User class, which allows user to input points into any of it's properties. However, there can be up to like 500 properties, everyone can have different ones, etc. So it would be a pain in the ass to code every property with "if: - elif:". Now this is what I tried to do, to make it much easier and cleaner: class User: def __init__(self): self.health = 0 self.speed = 0 def addPoint(self, property, amount): eval("self."+property) = eval("self."+property) + amount And now when I'd do fe. u = User() u.addPoint("health", 5) I would like it to do this: self.health = self.health + 5, and that's what I used the eval()s for. However, Python's just giving me error: can't assign to function call. I'm not trying to assign the eval() function call itself, I'm trying to assign the returned value from eval(), so how could I do this the easiest way?

    Read the article

  • How do I use accepts_nested_attributes_for? I cannot use the .build method (!)

    - by Angela
    Editing my question for conciseness and to update what I've done: How do I model having multiple Addresses for a Company and assign a single Address to a Contact, and be able to assign them when creating or editing a Contact? Here is my model for Contacts: class Contact < ActiveRecord::Base attr_accessible :first_name, :last_name, :title, :phone, :fax, :email, :company, :date_entered, :campaign_id, :company_name, :address_id, :address_attributes belongs_to :company belongs_to :address accepts_nested_attributes_for :address end Here is my model for Address: class Address < ActiveRecord::Base attr_accessible :street1, :street2, :city, :state, :zip has_many :contacts end I would like, when creating an new contact, access all the Addresses that belong to the other Contacts that belong to the Company. So here is how I represent Company: class Company < ActiveRecord::Base attr_accessible :name, :phone, :addresses has_many :contacts has_many :addresses, :through => :contacts end Here is how I am trying to create a field in the View for _form for Contact so that, when someone creates a new Contact, they pass the address to the Address model and associate that address to the Contact: <% f.fields_for :address, @contact.address do |builder| %> <p> <%= builder.label :street1, "Street 1" %> </br> <%= builder.text_field :street1 %> <p> <% end %> When I try to Edit, the field for Street 1 is blank. And I don't know how to display the value from show.html.erb. At the bottom is my error console -- can't seem to create values in the address table: My Contacts controller is as follows: def new @contact = Contact.new @contact.address.build # I GET AN ERROR HERE: says NIL CLASS @contact.date_entered = Date.today @campaigns = Campaign.find(:all, :order => "name") if params[:campaign_id].blank? else @campaign = Campaign.find(params[:campaign_id]) @contact.campaign_id = @campaign.id end if params[:company_id].blank? else @company = Company.find(params[:company_id]) @contact.company_name = @company.name end end def create @contact = Contact.new(params[:contact]) if @contact.save flash[:notice] = "Successfully created contact." redirect_to @contact else render :action => 'new' end end def edit @contact = Contact.find(params[:id]) @campaigns = Campaign.find(:all, :order => "name") end Here is a snippet of my error console: I am POSTING the attribute, but it is not CREATING in the Address table.... Processing ContactsController#create (for 127.0.0.1 at 2010-05-12 21:16:17) [POST] Parameters: {"commit"="Submit", "authenticity_token"="d8/gx0zy0Vgg6ghfcbAYL0YtGjYIUC2b1aG+dDKjuSs=", "contact"={"company_name"="Allyforce", "title"="", "campaign_id"="2", "address_attributes"={"street1"="abc"}, "fax"="", "phone"="", "last_name"="", "date_entered"="2010-05-12", "email"="", "first_name"="abc"}} Company Load (0.0ms)[0m [0mSELECT * FROM "companies" WHERE ("companies"."name" = 'Allyforce') LIMIT 1[0m Address Create (16.0ms)[0m [0;1mINSERT INTO "addresses" ("city", "zip", "created_at", "street1", "updated_at", "street2", "state") VALUES(NULL, NULL, '2010-05-13 04:16:18', NULL, '2010-05-13 04:16:18', NULL, NULL)[0m Contact Create (0.0ms)[0m [0mINSERT INTO "contacts" ("company", "created_at", "title", "updated_at", "campaign_id", "address_id", "last_name", "phone", "fax", "company_id", "date_entered", "first_name", "email") VALUES(NULL, '2010-05-13 04:16:18', '', '2010-05-13 04:16:18', 2, 2, '', '', '', 5, '2010-05-12', 'abc', '')[0m

    Read the article

  • trying to use ActiveRecord with Sinatra, Migration fails question

    - by David Lazar
    Hi, running Sinatra 1.0, I wanted to add a database table to my program. In my Rakefile I have a task task :environment do ActiveRecord::Base.establish_connection(YAML::load(File.open('config/database.yml'))["development"]) end I have a migration task in my namespace that calls the migration code: namespace :related_products do desc "run any migrations we may have in db/migrate" task :migrate => :environment do ActiveRecord::Migrator.migrate('db/migrate', ENV["VERSION"] ? ENV["VERSION"].to_i : nil ) end My console pukes out an error when the call to ActiveRecord::MIgrator.migrate() is made. rake aborted! undefined method `info' for nil:NilClass The migration code itself is pretty simple... and presents me with no clues as to what this missing info class is. class CreateStores < ActiveRecord::Migration def self.up create_table :stores do |t| t.string :name t.string :access_url t.timestamps end end def self.down drop_table :stores end end I am a little mystified here and am looking for some clues as to what might be wrong. Thanks!

    Read the article

  • how to format date when i load data from google-app-engine..

    - by zjm1126
    i use remote_api to load data from google-app-engine. appcfg.py download_data --config_file=helloworld/GreetingLoad.py --filename=a.csv --kind=Greeting helloworld the setting is: class AlbumExporter(bulkloader.Exporter): def __init__(self): bulkloader.Exporter.__init__(self, 'Greeting', [('author', str, None), ('content', str, None), ('date', str, None), ]) exporters = [AlbumExporter] and i download a.csv is : the date is not readable , and the date in appspot.com admin is : so how to get the full date ?? thanks i change this : class AlbumExporter(bulkloader.Exporter): def __init__(self): bulkloader.Exporter.__init__(self, 'Greeting', [('author', str, None), ('content', str, None), ('date', lambda x: datetime.datetime.strptime(x, '%m/%d/%Y').date(), None), ]) exporters = [AlbumExporter] but the error is :

    Read the article

  • Edit the opposite side of a many to many relationship with django generic form

    - by Ed
    I have two models: class Actor(models.Model): name = models.CharField(max_length=30, unique = True) event = models.ManyToManyField(Event, blank=True, null=True) class Event(models.Model): name = models.CharField(max_length=30, unique = True) long_description = models.TextField(blank=True, null=True) In a previous question: http://stackoverflow.com/questions/2503243/django-form-linking-2-models-by-many-to-many-field, I created an EventForm with a save function: class EventForm(forms.ModelForm): class Meta: model = Event def save(self, commit=True): instance = forms.ModelForm.save(self) instance.actors_set.clear() for actor in self.cleaned_data['actors']: instance.actors_set.add(actors) return instance This allowed me to add m2m links from the other side of the defined m2m connection. Now I want to edit the entry. I've been using a generic function: def generic_edit(request, modelname, object_id): modelname = modelname.lower() form_class = form_dict[modelname] return update_object(request, form_class = form_class, object_id = object_id, template_name = 'createdit.html' ) but this pulls in all the info except the many-to-many selections saved to this object. I think I need to do something similar to this: http://stackoverflow.com/questions/1700202/editing-both-sides-of-m2m-in-admin-page, but I haven't figured it out. How do I use the generic update_object to edit the other side of many-to-many link?

    Read the article

  • How do I find the "concrete class" of a django model baseclass

    - by Mr Shark
    I'm trying to find the actual class of a django-model object, when using model-inheritance. Some code to describe the problem: class Base(models.model): def basemethod(self): ... class Child_1(Base): pass class Child_2(Base): pass If I create various objects of the two Child classes and the create a queryset containing them all: Child_1().save() Child_2().save() (o1, o2) = Base.objects.all() I want to determine if the object is of type Child_1 or Child_2 in basemethod, I can get to the child object via o1.child_1 and o2.child_2 but that reconquers knowledge about the childclasses in the baseclass. I have come up with the following code: def concrete_instance(self): instance = None for subclass in self._meta.get_all_related_objects(): acc_name = subclass.get_accessor_name() try: instance = self.__getattribute__(acc_name) return instance except Exception, e: pass But it feels brittle and I'm not sure of what happens when if I inherit in more levels.

    Read the article

  • Why is the destructor called when the CPython garbage collector is disabled?

    - by Frederik
    I'm trying to understand the internals of the CPython garbage collector, specifically when the destructor is called. So far, the behavior is intuitive, but the following case trips me up: Disable the GC. Create an object, then remove a reference to it. The object is destroyed and the __del__ method is called. I thought this would only happen if the garbage collector was enabled. Can someone explain why this happens? Is there a way to defer calling the destructor? import gc import unittest _destroyed = False class MyClass(object): def __del__(self): global _destroyed _destroyed = True class GarbageCollectionTest(unittest.TestCase): def testExplicitGarbageCollection(self): gc.disable() ref = MyClass() ref = None # The next test fails. # The object is automatically destroyed even with the collector turned off. self.assertFalse(_destroyed) gc.collect() self.assertTrue(_destroyed) if __name__=='__main__': unittest.main() Disclaimer: this code is not meant for production -- I've already noted that this is very implementation-specific and does not work on Jython.

    Read the article

  • How do we know if a query is cache or retrieved from database?

    - by Hadi
    For example: class Product has_many :sales_orders def total_items_deliverable self.sales_orders.each { |so| #sum the total } #give back the value end end class SalesOrder def self.deliverable # return array of sales_orders that are deliverable to customer end end SalesOrder.deliverable #give all sales_orders that are deliverable to customer pa = Product.find(1) pa.sales_orders.deliverable #give all sales_orders whose product_id is 1 and deliverable to customer pa.total_so_deliverable The very point that i'm going to ask is: how many times SalesOrder.deliverable is actually computed, from point 1, 3, and 4, They are computed 3 times that means 3 times access to database so having total_so_deliverable is promoting a fat model, but more database access. Alternatively (in view) i could iterate while displaying the content, so i ends up only accessing the database 2 times instead of 3 times. Any win win solution / best practice to this kind of problem ?

    Read the article

  • Printing to STDOUT and log file while removing ANSI color codes

    - by Arrieta
    I have the following functions for colorizing my screen messages: def error(string): return '\033[31;1m' + string + '\033[0m' def standout(string): return '\033[34;1m' + string + '\033[0m' I use them as follows: print error('There was a problem with the program') print "This is normal " + standout("and this stands out") I want to log the output to a file (in addition to STDOUT) WITHOUT the ANSI color codes, hopefully without having to add a second "logging" line to each print statement. The reason is that if you simply python program.py > out then the file out will have the ANSI color codes, which look terrible if you open in a plain text editor. Any advice?

    Read the article

  • Update User Info with restful_authentication plugin in Rails?

    - by benoror
    Hi people, I want to give the users the ability to change their account info with restful_authentication plugin in rails. I added this two methods to my users controller: def edit @user = User.find(params[:id]) end def update @user = User.find(params[:id]) # Only update password when necessary params[:user].delete(:password) if pàrams[:user][:password].blank? respond_to do |format| if @user.update_attributes(params[:user]) flash[:notice] = 'User was successfully updated.' format.html { redirect_to(@user) } format.xml { head :ok } else format.html { render :action => "edit" } format.xml { render :xml => @user.errors, :status => :unprocessable_entity } end end end Also, I copied new.html.erb to edit.html.erb. Considering that resources are already defined in routes.rb I was expecting it to work easily, bute somehow when I click the save button it calls the create method, instead of update, using a POST http request. Inmediatly after that it autocatically log out form the session. Any ideas?

    Read the article

  • Ruby on Rails: attr_accessor for submodels

    - by williamjones
    I'm working with some models where a lot of a given model's key attributes are actually stored in a submodel. Example: class WikiArticle has_many :revisions has_one :current_revision, :class_name => "Revision", :order => "created_at DESC" end class Revision has_one :wiki_article end The Revision class has a ton of database fields, and the WikiArticle has very few. However, I often have to access a Revision's fields from the context of a WikiArticle. The most important case of this is probably on creating an article. I've been doing that with lots of methods that look like this, one for each field: def description if @description @description elsif current_revision current_revision.description else "" end end def description=(string) @description = string end And then on my save, I save @description into a new revision. This whole thing reminds me a lot of attr_accessor, only it doesn't seem like I can get attr_accessor to do what I need. How can I define an attr_submodel_accessor such that I could just give field names and have it automatically create all those methods the way attr_accessor does?

    Read the article

  • AuthLogic perishable_token resets on every request

    - by go minimal
    In my User model I have: acts_as_authentic do |c| c.perishable_token_valid_for = 30.minutes end In my Application Controller I have the standard boilerplate code: def current_user_session return @current_user_session if defined?(@current_user_session) @current_user_session = UserSession.find end def current_user return @current_user if defined?(@current_user) @current_user = current_user_session && current_user_session.record end Now in my view I need to see if a user is logged in: <% if current_user %> Sign Out <% else %> Sign In <% end %> On every single request, current_user is being called, and that causes a SELECT call to be made to the database to find the user, then an UPDATE call that updates the last_request_at and perishable_token even though I set perishable_token_valid_for = 30.minutes. Does anyone have a better way to see if a user is logged in without causing a SELECT and UPDATE on every single page of my app. Does anyone know why the perishable token keeps updating even if I set it to be valid for 30 minutes???

    Read the article

  • How is includegraphic interfering with tabular?

    - by Charles Stewart
    I'm editing a text provided by my client as a LyX file that includes graphics and other files that I don't have. I've "commented out" the graphics by putting in a custom preamble that substitutes the file-loading definitions with macros that just quote their arguments. However, the \includegraphic macro throws up an error in the two tabular environments where it is used, complaining that \endfirsthead was never defined. What is this macro, and why is it interfering with mine? The preamble: \usepackage{natbib} \def\fileloc{/some/path/stylefile} \newif\iftextproof \IfFileExists\alifefileloc\textproofalse\textprooftrue \iftextproof \usepackage{./stylefile} %natbib subst: \renewcommand\cite[1]{{\tt #1}} %suppress graphics includes: \def\quotearg#1{\expandafter\string\csname #1\endcsname} \newcommand\gobbleIG[2][*void*]{{\footnotesize \quotearg{#2}}} \newcommand\gobbleSF[2][*unnamed*]{{\bf #1}} \let\includegraphics=\gobbleIG \let\subfigure=\gobbleSF \else \usepackage\fileloc \fi

    Read the article

  • C# extension method doesn't seem to exist

    - by blahblah
    I can't seem to get the following extension method to be found in another class in the same namespace (MyProject.Util). using System.Collections.Specialized; namespace MyProject.Util { public static class Extensions { public static string Get( this NameValueCollection me, string key, string def ) { return me[key] ?? def; } } } As you can see it's basically another version of foo[bar] ?? baz, but I still don't understand why VS2008 fails to compile telling me that no version of Get takes two arguments. Any ideas?

    Read the article

  • escaping a dollar in the middle of an ant property

    - by jk
    I have a property whose value contains a $. I'd like to use this property as a regexp in a propertyregexp. Ant appears to resolve the property as a paramater to the propertyregexp, but then the dollar gets interpreted as a regexp symbol. Example: <property name="a" value="abc$" /> <property name="b" value="xyz" /> <path id="paths"> <pathelement location="abc$/def" /> <pathelement location="abc$/ghi" /> </path> <pathconvert property="list" refid="paths" pathsep="${line.separator}" dirsep="/" /> <propertyregex property="list" input="${list}" override="true" regexp="${a}(.*)" replace="${b}\1" /> <echo message="${list}" /> I'd like to the pair xyz/def and xyz/ghi. Is this possible? I'm using Ant 1.8.

    Read the article

  • Difficulty adding widgets to django form.

    - by codingJoe
    I have a django app that tracks activities that can benefit a classroom. Using the django examples, I was able to build a form to enter this data. But when I try to add widgets to that form, things get tricky. What I want is a calendar widget that lets the user enter the 'activity_date' field using a widget. If I use Admin interface. The AdminDateWidget works fine. however. This particular user isn't allowed access to the admin interface so I need a different way to present this widget. Also I couldn't figure out how to make the bring the admin widget over into non-admin pages. So I tried a custom widget. This is the first custom widget I've built, so I'm not quite sure what is supposed to be going on here. Any Expert Advice? How do I get my date widget to work? # The Model class Activity(models.Model): activity_date = models.DateField() activity_type = models.CharField(max_length=50, choices=ACTIVITY_TYPES) activity_description = models.CharField(max_length=200) activity_duration= models.DecimalField(decimal_places=2, max_digits=4) est_attendance = models.IntegerField("Estimated attendance") # The Form class ActivityForm(forms.ModelForm): # The following line causes lockup if enabled. # With the DateTimeWidget removed, the form functions correctly except that there is no widget. #activity_date = forms.DateField(label=_('Date'), widget=DateTimeWidget) ##!!! Point of Error !!! class Meta: model = Activity fields = ('activity_date', 'activity_type', 'activity_description', 'activity_duration', 'est_attendance') def __init__(self, *args, **kwargs): super(ActivityForm, self).__init__(*args, **kwargs) instance = getattr(self, 'instance', None) edit_aid = kwargs.get('edit_aid', False) # On a different approach, the following also didn't work. #self.fields['activity_date'].widget = widgets.AdminDateWidget() # The Widget # Example referenced: http://djangosnippets.org/snippets/391/ calbtn = u""" <button id="calendar-trigger">...</button> <img src="%s/site_media/images/icon_calendar.gif" alt="calendar" id="%s_btn" style="cursor: pointer; border: 1px solid #8888aa;" title="Select date and time" onmouseover="this.style.background='#444444';" onmouseout="this.style.background=''" /> <script type="text/javascript"> Calendar.setup({ trigger : "calendar-trigger", inputField : "%s" }); </script>""" class DateTimeWidget(forms.widgets.TextInput): dformat = '%Y-%m-%d %H:%M' def render(self, name, value, attrs=None): print "DTWgt render name=%s, value=%s" % name, value if value is None: value = '' final_attrs = self.build_attrs(attrs, type=self.input_type, name=name) if value != '': try: final_attrs['value'] = \ force_unicode(value.strftime(self.dformat)) except: final_attrs['value'] = \ force_unicode(value) if not final_attrs.has_key('id'): final_attrs['id'] = u'%s_id' % (name) id = final_attrs['id'] jsdformat = self.dformat #.replace('%', '%%') cal = calbtn % (settings.MEDIA_URL, id, id, jsdformat, id) a = u'<input%s />%s' % (forms.util.flatatt(final_attrs), cal) print "render return %s " % a return mark_safe(a) def value_from_datadict(self, data, files, name): print "DTWgt value_from_datadict" dtf = forms.fields.DEFAULT_DATETIME_INPUT_FORMATS empty_values = forms.fields.EMPTY_VALUES value = data.get(name, None) if value in empty_values: return None if isinstance(value, datetime.datetime): return value if isinstance(value, datetime.date): return datetime.datetime(value.year, value.month, value.day) for format in dtf: try: return datetime.datetime(*time.strptime(value, format)[:6]) except ValueError: continue return None

    Read the article

  • Multiple Context menus in PyQt based on mouse location

    - by Nader
    I have a window with multiple tables using QTableWidget (PyQt). I created a popup menu using the right click mouse and it works fine. However, I need to create different popup menu based on which table the mouse is hovering over at the time the right mouse is clicked. How can I get the mouse to tell me which table it is hovering over? or, put in another way, how to implement a method so as to have a specific context menu based on mouse location? I am using Python and PyQt. My popup menu is developed similar to this code (PedroMorgan answer from Qt and context menu): class Foo( QtGui.QWidget ): def __init__(self): QtGui.QWidget.__init__(self, None) # Toolbar toolbar = QtGui.QToolBar() # Actions self.actionAdd = toolbar.addAction("New", self.on_action_add) self.actionEdit = toolbar.addAction("Edit", self.on_action_edit) self.actionDelete = toolbar.addAction("Delete", self.on_action_delete) # Tree self.tree = QtGui.QTreeView() self.tree.setContextMenuPolicy( Qt.CustomContextMenu ) self.connect(self.tree, QtCore.SIGNAL('customContextMenuRequested(const QPoint&)'), self.on_context_menu) # Popup Menu self.popMenu = QtGui.QMenu( self ) self.popMenu.addAction( self.actionEdit ) self.popMenu.addAction( self.actionDelete ) self.popMenu.addSeparator() self.popMenu.addAction( self.actionAdd ) def on_context_menu(self, point): self.popMenu.exec_( self.tree.mapToGlobal(point) )

    Read the article

  • Django Initial for a ManyToMany Field

    - by gramware
    I have a form that edits an instance of my model. I would like to use the form to pass all the values as hidden with an inital values of username defaulting to the logged in user so that it becomes a subscribe form. The problem is that the normal initial={'field':value} doesn't seem to work for manytomany fields. how do i go about it? my views.py @login_required def event_view(request,eventID): user = UserProfile.objects.get(pk=request.session['_auth_user_id']) event = events.objects.get(eventID = eventID) if request.method == 'POST': form = eventsSusbcribeForm( request.POST,instance=event) if form.is_valid(): form.save() return HttpResponseRedirect('/events/') else: form = eventsSusbcribeForm(instance=event) return render_to_response('event_view.html', {'user':user,'event':event, 'form':form},context_instance = RequestContext( request )) my forms.py class eventsSusbcribeForm(forms.ModelForm): eventposter = forms.ModelChoiceField(queryset=UserProfile.objects.all(), widget=forms.HiddenInput()) details = forms.CharField(widget=forms.Textarea(attrs={'cols':'50', 'rows':'5'}),label='Enter Event Description here') date = forms.DateField(widget=SelectDateWidget()) class Meta: model = events exclude = ('deleted') def __init__(self, *args, **kwargs): super(eventsSusbcribeForm, self).__init__(*args, **kwargs) self.fields['username'].initial = (user.id for user in UserProfile.objects.filter())

    Read the article

  • setting url in yaml file for google app engin (page not found) problem

    - by mswallace
    I am new to python and I am super excited to learn. I am building my first app on app engin and I am not totally understanding why my yaml file is not resolving to the url that I set up. here is the code handlers: - url: .* script: main.py - url: /letmein/.* script: letmein.py so if I go to http://localhost:8080/letmein/ I get a link is brooken or page not found error. here is the python code that I have in letmein.py from google.appengine.ext import webapp from google.appengine.ext.webapp import util class LetMeInHandler(webapp.RequestHandler): def get(self): self.response.out.write('letmein!') def main(): application = webapp.WSGIApplication([('/letmein/', LetMeInHandler)], debug=True) util.run_wsgi_app(application) if __name__ == '__main__': main() thanks in advance for the help!

    Read the article

  • SQLAlchemy unsupported type error - and table design issues?

    - by Az
    Hi there, back again with some more SQLAlchemy shenanigans. Let me step through this. My table is now set up as so: engine = create_engine('sqlite:///:memory:', echo=False) metadata = MetaData() students_table = Table('studs', metadata, Column('sid', Integer, primary_key=True), Column('name', String), Column('preferences', Integer), Column('allocated_rank', Integer), Column('allocated_project', Integer) ) metadata.create_all(engine) mapper(Student, students_table) Fairly simple, and for the most part I've been enjoying the ability to query almost any bit of information I want provided I avoid the error cases below. The class it is mapped from is: class Student(object): def __init__(self, sid, name): self.sid = sid self.name = name self.preferences = collections.defaultdict(set) self.allocated_project = None self.allocated_rank = 0 def __repr__(self): return str(self) def __str__(self): return "%s %s" %(self.sid, self.name) Explanation: preferences is basically a set of all the projects the student would prefer to be assigned. When the allocation algorithm kicks in, a student's allocated_project emerges from this preference set. Now if I try to do this: for student in students.itervalues(): session.add(student) session.commit() It throws two errors, one for the allocated_project column (seen below) and a similar error for the preferences column: sqlalchemy.exc.InterfaceError: (InterfaceError) Error binding parameter 4 - probably unsupported type. u'INSERT INTO studs (sid, name, allocated_rank, allocated_project) VALUES (?, ?, ?, ?, ?, ?, ?)' [1101, 'Muffett,M.', 1, 888 Human-spider relationships (Supervisor id: 123)] If I go back into my code I find that, when I'm copying the preferences from the given text files, it actually refers to the Project class which is mapped to a dictionary, using the unique project id's (pid) as keys. Thus, as I iterate through each student via their rank and to the preferences set, it adds not a project id, but the reference to the project id from the projects dictionary. students[sid].preferences[int(rank)].add(projects[int(pid)]) Now this is very useful to me since I can find out all I want to about a student's preferred projects without having to run another check to pull up information about the project id. The form you see in the error has the object print information passed as: return "%s %s (Supervisor id: %s)" %(self.proj_id, self.proj_name, self.proj_sup) My questions are: I'm trying to store an object in a database field aren't I? Would the correct way then, be copying the project information (project id, name, etc) into its own table, referenced by the unique project id? That way I can just have the project id field for one of the student tables just be an integer id and when I need more information, just join the tables? So and so forth for other tables? If the above makes sense, then how does one maintain the relationship with a column of information in one table which is a key index on another table? Does this boil down into a database design problem? Are there any other elegant ways of accomplishing this? Apologies if this is a very long-winded question. It's rather crucial for me to solve this, so I've tried to explain as much as I can, whilst attempting to show that I'm trying (key word here sadly) to understand what could be going wrong.

    Read the article

  • how to pass in dynamic data to decorators

    - by steve
    Hi, I am trying to write a base crud controller class that does the following: class BaseCrudController: model = "" field_validation = {} template_dir = "" @expose(self.template_dir) def new(self, *args, **kwargs) .... @validate(self.field_validation, error_handler=new) @expose() def post(self, *args, **kwargs): ... My intent is to have my controllers extend this base class, set the model, field_validation, and template locations, and am ready to go. Unfortunately, decorators (to my understanding), are interpreted when the function is defined. Hence it won't have access to instance's value. Is there a way to pass in dynamic data or values from the sub class? If not, I guess I could use override_template as a workaround to expose and set the template within the controller action. How would I go about validating the form within the controller action? Thanks, Steve

    Read the article

  • Django: Determining if a user has voted or not

    - by TheLizardKing
    I have a long list of links that I spit out using the below code, total votes, submitted by, the usual stuff but I am not 100% on how to determine if the currently logged in user has voted on a link or not. I know how to do this from within my view but do I need to alter my below view code or can I make use of the way templates work to determine it? I have read http://stackoverflow.com/questions/1528583/django-vote-up-down-method but I don't quite understand what's going on ( and don't need any ofjavascriptery). Models (snippet): class Link(models.Model): category = models.ForeignKey(Category, blank=False, default=1) user = models.ForeignKey(User) created = models.DateTimeField(auto_now_add=True) modified = models.DateTimeField(auto_now=True) url = models.URLField(max_length=1024, unique=True, verify_exists=True) name = models.CharField(max_length=512) def __unicode__(self): return u'%s (%s)' % (self.name, self.url) class Vote(models.Model): link = models.ForeignKey(Link) user = models.ForeignKey(User) created = models.DateTimeField(auto_now_add=True) def __unicode__(self): return u'%s vote for %s' % (self.user, self.link) Views (snippet): links = Link.objects.select_related().annotate(votes=Count('vote')).order_by('-created')

    Read the article

  • In Ruby, how does coerce() actually work?

    - by Jian Lin
    It is said that when we have a class Point and knows how to perform point * 3 like the following: class Point def initialize(x,y) @x, @y = x, y end def *(c) Point.new(@x * c, @y * c) end end point = Point.new(1,2) p point p point * 3 Output: #<Point:0x336094 @x=1, @y=2> #<Point:0x335fa4 @x=3, @y=6> but then, 3 * point is not understood: Point can't be coerced into Fixnum (TypeError) So we need to further define an instance method coerce: class Point def coerce(something) [self, something] end end p 3 * point Output: #<Point:0x3c45a88 @x=3, @y=6> So it is said that 3 * point is the same as 3.*(point) that is, the instance method * takes an argument point and invoke on the object 3. Now, since this method * doesn't know how to multiply a point, so point.coerce(3) will be called, and get back an array: [point, 3] and then * is once again applied to it, is that true? point * 3 which is the same as point.*(3) and now, this is understood and we now have a new Point object, as performed by the instance method * of the Point class. The question is: 1) who invokes point.coerce(3) ? Is it Ruby automatically, or is it some code inside of * method of Fixnum by catching an exception? Or is it by case statement that when it doesn't know one of the known types, then call coerce? 2) Does coerce always need to return an array of 2 elements? Can it be no array? Or can it be an array of 3 elements? 3) And is the rule that, the original operator (or method) * will then be invoked on element 0, with the argument of element 1? (element 0 and element 1 are the two elements in that array returned by coerce) Who does it? Is it done by Ruby or is it done by code in Fixnum? If it is done by code in Fixnum, then it is a "convention" that everybody follows when doing a coerce? So could it be the code in * of Fixnum do something like this: if (something.typeof? ...) else if ... # other type else if ... # other type else # if it is not a type I know array = something.coerce(self) return array[0].*(array[1]) end

    Read the article

< Previous Page | 63 64 65 66 67 68 69 70 71 72 73 74  | Next Page >