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  • Good Domain Driven Design samples

    - by jlembke
    I'm learning about DDD and enjoying every minute of it. However, there are some practical issues that are confusing to me that I think seeing some good samples might clear up. So being at peace with those issues, does anyone know of some good working code samples that do a good job of modeling basic DDD concepts? Particularly interested in An illustrative Domain Model Repositories Use of Domain/Application Services Value Objects Aggregate Roots I know I'm probably asking for too much, but anything close will help.

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  • Schema qualified tables with SQLAlchemy, SQLite and Postgresql?

    - by Chris Reid
    I have a Pylons project and a SQLAlchemy model that implements schema qualified tables: class Hockey(Base): __tablename__ = "hockey" __table_args__ = {'schema':'winter'} hockey_id = sa.Column(sa.types.Integer, sa.Sequence('score_id_seq', optional=True), primary_key=True) baseball_id = sa.Column(sa.types.Integer, sa.ForeignKey('summer.baseball.baseball_id')) This code works great with Postgresql but fails when using SQLite on table and foreign key names (due to SQLite's lack of schema support) sqlalchemy.exc.OperationalError: (OperationalError) unknown database "winter" 'PRAGMA "winter".table_info("hockey")' () I'd like to continue using SQLite for dev and testing. Is there a way of have this fail gracefully on SQLite?

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  • How can I setup a simple custom route using Zend Framework's Zend_Application?

    - by Billy ONeal
    I'm looking to setup a custom route which supplies implicit parameter names to a Zend_Application. Essentially, I have an incoming URL which looks like this: /StandardSystems/Dell/LatitudeE6500 I'd like that to be mapped to the StandardsystemsController, and I'd like that controller to be passed parameters "make" => "Dell" and "model" => "LatitudeE6500". How can I setup such a system using Zend_Application?

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  • Generate CSV file from rails

    - by Elliot
    I've been reading similar questions, but many of the answers are outdated or not clear enough for me. I'd like to be able to just do something like (in a controller action): respond_to do |format| format.html format.csv end I know I'd then need a view such as action.csv.erb So my questions are: 1) What do I need to configure in rails to allow this to happen in general. 2) How should I setup the CSV view to display some basic fields from a model?

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  • Classification of relationships in words?

    - by C.
    Hi, I'm not sure whats the best algorithm to use for the classification of relationships in words. For example in the case of a sentence such as "The yellow sun" there is a relationship between yellow and sun. THe machine learning techniques I have considered so far are Baynesian Statistics, Rough Sets, Fuzzy Logic, Hidden markov model and Artificial Neural Networks. Any suggestions please? thank you :)

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  • DB Designer creates compound primary key

    - by Jon Winstanley
    When adding relationships to a database model in DB Designer 4, a composite primary key is being created every time. So every foreign key I add, I get an extra key added to a composite primary key. I think I must have changed a setting as I don't remember it doing this in the past. Does anyone know how to turn off this feature as I prefer to use a single surrogate primary keys in my database tables?

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  • How can I run .aggregate() on a field introduced using .extra(select={...}) in a Django Query?

    - by Jake
    I'm trying to get the count of the number of times a player played each week like this: player.game_objects.extra(select={'week': 'WEEK(`games_game`.`date`)'}).aggregate(count=Count('week')) But Django complains that FieldError: Cannot resolve keyword 'week' into field. Choices are: <lists model fields> I can do it in raw SQL like this SELECT WEEK(date) as week, COUNT(WEEK(date)) as count FROM games_game WHERE player_id = 3 GROUP BY week Is there a good way to do this without executing raw SQL in Django?

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  • Accessing updated M2M fields in overriden save() in django's admin

    - by Jonathan
    I'd like to use the user updated values of a ManyToManyField in a model's overriden save() method when I save an instance in admin. It turns out that by design, django does not update the M2M field before calling save(), but only after the save() is complete as part of the form save... How can I access the new values of this field in the override save() ?

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  • Dynamic URL -> Controller mapping for routes in Rails

    - by Daniel Beardsley
    I would like to be able to map URLs to Controllers dynamically based on information in my database. I'm looking to do something functionally equivalent to this (assuming a View model): map.route '/:view_name', :controller => lambda { View.find_by_name(params[:view_name]).controller } Others have suggested dynamically rebuilding the routes, but this won't work for me as there may be thousands of Views that map to the same Controller

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  • What is the best scripting language to embed in a C# desktop application.

    - by Ewan Makepeace
    We are writing a complex rich desktop application and need to offer flexibility in reporting formats so we thought we would just expose our object model to a scripting langauge. Time was when that meant VBA (which is still an option), but the managed code derivative VSTA (I think) seems to have withered on the vine. What is now the best choice for an embedded scripting language on Windows .NET?

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  • Django select max id

    - by pistacchio
    Hi, given a standard model (called Image) with an autoset 'id', how do I get the max id? So far I've tried: max_id = Image.objects.all().aggregate(Max('id')) but I get a 'id__max' Key error. Trying max_id = Image.objects.order_by('id')[0].id gives a 'argument 2 to map() must support iteration' exception Any help?

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  • How to elegantly create a datatable with Django ?

    - by Inshim
    Here's a common situation that I have and wish to avoid creating tedious loops and fiddling with html tables: I have a model Movie, which is has fkeys to Director and to Genre. How can I elegantly render a simple data table that has on one axis the different Directors, on another axis the different Genres, and inside each cell the count of the movies filtered by the respective Director and Genre? Thanks!

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  • Why do people hate SQL cursors so much?

    - by Steven A. Lowe
    I can understand wanting to avoid having to use a cursor due to the overhead and inconvenience, but it looks like there's some serious cursor-phobia-mania going on where people are going to great lengths to avoid having to use one for example, one question asked how to do something obviously trivial with a cursor and the accepted answer proposed using a common table expression (CTE) recursive query with a recursive custom function, even though this limits the number of rows that could be processed to 32 (due to recursive call limit in sql server). This strikes me as a terrible solution for system longevity, not to mention a tremendous effort just to avoid using a simple cursor. what is the reason for this level of insane hatred? has some 'noted authority' issued a fatwa against cursors? does some unspeakable evil lurk in the heart of cursors that corrupts the morals of the children or something? wiki question, more interested in the answer than the rep thanks in advance! Related Info: http://stackoverflow.com/questions/37029/sql-server-fast-forward-cursors EDIT: let me be more precise: I understand that cursors should not be used instead of normal relational operations, that is a no-brainer. What I don't understand is people going waaaaay out of their way to avoid cursors like they have cooties or something, even when a cursor is a simpler and/or more efficient solution. It's the irrational hatred that baffles me, not the obvious technical efficiencies.

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  • Why can't I create a database in an empty ASP MVC 2 project using Project->Add->New Item->SQL Server

    - by Dr Dork
    I'm diving head first into ASP MVC and am playing around with creating and manipulating a database. I did a search and found this tutorial for creating a database, however when I follow it, I get this error when trying to add a new database to my fresh, empty ASP MVC 2 project... A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) The only requirement the tutorial mentioned was SQL Server Express, but when I went to download it, it said it was already installed. I'm assuming it was part of the VS 2010 RC I installed and am running. So I don't know what else I need if I am missing something. This is all new to me, so I'm sure I'm missing something obvious here and after I'm done posting this question, I plan to do some more research into the topic of databases and how they work with ASP MVC. In the meantime, I was you could help me answer a couple high level questions... What am I missing/forgetting to do that is causing this error? Any suggestions for good resources/tutorials that focus on using databases with ASP MVC? I've done a lot of database programming in the past, so I'm familiar with the concepts of relational databases and the SQL language. I wish I could find a good resource for learning how to work with them in an ASP dev environment, as well as a good breakdown of all the related technologies used for working with them (i.e. LINQ to SQL). Thanks so much in advance for all your help! I'm going to start researching these questions right now.

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  • How to change the coordinate origin in Flash's stage with Actionscript?

    - by Petruza
    I think I did this before but can't find the code. Flash as many other graphical frameworks use the top-left corner as the coordinate origin (0,0) because it's how the underlying memory model is by convention. But it would be really simpler for my calculations if the origin was in the center of the stage, because all the game revolves around the center and uses a lot of trigonometry, angles, etc. Is there some built-in method like Stage::setOrigin( uint, uint ); or something like that?

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  • searchlogic and virtual attributes

    - by Ermin
    Let's say I have the following model: Person <AR def name [self.first_name,self.middle_name,self.last_name].select{|n| n.present?}.join(' ') end end How could I do a search on the virtual attribute with searchlogic, something like: Person.search.name_like 'foo' Of courese I could construct a large statement like: Person.search.first_name_like_or_last_name_like_or_... 'argh' but surely there is a more elegant way.

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  • How to get Eclipse + PyDev + App Engine + Unit testing to work?

    - by PEZ
    I want to run my unit tests for a Python Google App Engine project using Run As = Python unit-test But when I try that all my Model tests bail with the error message: BadArgumentError: app must not be empty. Anyone got this to work? NB: The tests runs fine using Nose --with-gae. But I want the PyDev integration with hyperlinking of resources and such.

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  • Symfony fk issue on insertion

    - by Daniel Hertz
    Hi, I posted a similar problem but it could not be resolved. I create a relational database of users and groups but for some reason I cannot insert test data with fixtures properly. Here is a sample of the schema: User: actAs: { Timestampable: ~ } columns: name: { type: string(255), notnull: true } email: { type: string(255), notnull: true, unique: true } nickname: { type: string(255), unique: true } password: { type: string(300), notnull: true } image: { type: string(255) } Group: actAs: { Timestampable: ~ } columns: name: { type: string(500), notnull: true } image: { type: string(255) } type: { type: string(255), notnull: true } created_by_id: { type: integer } relations: User: { onDelete: SET NULL, class: User, local: created_by_id, foreign: id, foreignAlias: groups_created } FanOf: actAs: { Timestampable: ~ } columns: user_id: { type: integer, primary: true } group_id: { type: integer, primary: true } relations: User: { onDelete: CASCADE, local: user_id, foreign: id, foreignAlias: fanhood } Group: { onDelete: CASCADE, local: group_id, foreign: id, foreignAlias: fanhood } And this is the data i try to input: User: user1: name: Danny email: [email protected] nickname: danny password: f05050400c5e586fa6629ef497be Group: group1: name: Mets type: sports FanOf: fans1: user_id: user1 group_id: group1 I keep getting this error: SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (`krowdd`.`fan_of`, CONSTRAINT `fan_of_user_id_user_id` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`) ON DELETE CASCADE) The users and groups are clearly being created before the "fanhood" is so why am I getting this error?? Thanks!

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  • passing multiple vectors to function by reference (using structure)

    - by madman
    Hi StackOverflow, Can someone tell me the correct way of passing multiple vectors to a function that can take only a single argument? (specifically for pthread_create (..) function) I tried the following but it does not seem to work :-( First, I created the following structure struct ip2 { void* obj; int dim; int n_s; vector<vector<vector<double> > > *wlist; vector<int> *nrsv; struct model *pModel; }; The threads that I have created actually needs all these parameters. Since im using pthreads_create I put all this in a structure and then passed the pointer to the structure as an argument to pthread_create (as shown). some_fxn() { //some code struct ip2 ip; ip.obj=(void*) this; ip.n_s=n_s; ip.wlist=&wlist; ip.nrsv=&nrsv; ip.pModel=pModel; ip.dim=dim; pthread_create(&callThd1[lcntr], &attr1, &Cls::Entry, (void*) &ip); } The Entry method looks something like this. void* Cls::Entry(void *ip) { struct ip2 *x; x = (struct ip2 *)ip; (reinterpret_cast<Cls1 *>(x->obj))->Run(x->dim,x->n_s, x->wlist, x->nrsv, x->pModel); } The Run method looks something like this. void Run(int dim, int n_c, vector<vector<vector<double> > > *wlist, vector<int> *nrsv, struct model* pModel ) { //some code for(int k = 0; k < n_c; ++k) { //some code end = index + nrsv[k]; //some code } I get the following error when I try to compile the program. error: no match for ‘operator+’ in ‘index + *(((std::vector<int, std::allocator<int> >*)(((unsigned int)k) * 12u)) + nrsv)’ Can someone tell me how to do it the right way. Madhavan

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