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  • How can I override the attribute assignment in an active record object?

    - by ryeguy
    I know you can do this with virtual attributes, but what if the column actually exists? For example, my model has a raw_topic column. When raw_topic is set, I want artist and song_title to be set based off of raw_topic's contents. Ideally, I'd like to override the raw_topic= method, but rails doesn't seem to like that. What's the proper way of doing this? Is a callback the only way?

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  • What database strategy to choose for a large web application

    - by Snoopy
    I have to rewrite a large database application, running on 32 servers. The hardware is up to date, each machine has two quad core Xeon and 32 GByte RAM. The database is multi-tenant, each customer has his own file, around 5 to 10 GByte each. I run around 50 databases on this hardware. The app is open to the web, so I have no control on the load. There are no really complex queries, so SQL is not required if there is a better solution. The databases get updated via FTP every day at midnight. The database is read-only. C# is my favourite language and I want to use ASP.NET MVC. I thought about the following options: Use two big SQL servers running SQL Server 2012 to serve the 32 servers with data. On the 32 servers running IIS hosting providing REST services. Denormalize the database and use Redis on each webserver. Use booksleeve as a Redis client. Use a combination of SQL Server and Redis Use SQL Server 2012 together with Hadoop Use Hadoop without SQL Server What is the best way for a read-only database, to get the best performance without loosing maintainability? Does Map-Reduce make sense at all in such a scenario? The reason for the rewrite is, the old app written in C++ with ISAM technology is too slow, the interfaces are old fashioned and not nice to use from an website, especially when using ajax. The app uses a relational datamodel with many tables, but it is possible to write one accerlerator table where all queries can be performed on, and all other information from the other tables are possible by a simple key lookup.

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  • Custom search engine in asp.net mvc and entity framework

    - by Rahat
    Hi, does anyone have any idea how I can get started building a search engine for my asp.net mvc site using entity framework. I plan to build something like: http://www.carsguide.com.au/search/?N=4294962119++492&type=cars there on the left there is a refine search option panel. What's the best approach to design a model for the UI and optimized query with entity framework.

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  • Scaffold is ignoring class file in CakePHP

    - by JoseMarmolejos
    Hi, when using scaffolding on a controller the views render fine and the app even attempts to insert the data; the problem is that the scaffold is completely ignoring the relations I'm defining in my model class, in fact it's ignoring the class entirely as I can delete the file and the controller still scaffolds and render the crud from the table. Has this ever happened to you?

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  • PHP ORM library based on the Data Mapper pattern

    - by Matthieu
    For a PHP application with a complex domain model, I don't want to use the Active Record pattern, I need instead the Data Mapper pattern (as presented in Zend Framework). Do you know any library that could help me for the ORM part, or else a link to a documentation on "how to do it right" ? Thanks

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  • XCode CoreData files not found/opening

    - by jAmi
    Hello, I am using the Xcode 3.1.4 that means SDK 3.1.2 The problem is that I cannot open .xcdatamodel (Core Data) file and I don't even get the Data Model option in Design Menu bar. When ever I double click and try to open the file, XCode gives me an error saying that it cannot find the file at (my project's path).Perhaps it was moved or deleted? , but the file exists at the same path. Please help me out as I haven't upgraded my system to Snow Leopard so cant use SDK 3.2 Regards jAmi

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  • Is a Multi-DAL Approach the way to go here?

    - by Krisc
    Working on the data access / model layer in this little MVC2 project and trying to think things out to future projects. I have a database with some basic tables and I have classes in the model layer that represent them. I obviously need something to connect the two. The easiest is to provide some sort of 'provider' that can run operations on the database and return objects. But this is for a website that would potentially be used "a lot" (I know, very general) so I want to cache results from the data layer and keep the cache updated as new data is generated. This question deals with how best to approach this problem of dual DALS. One that returns cached data when possible and goes to the data layer when there is a cache miss. But more importantly, how to integrate the core provider (thing that goes into database) with the caching layer so that it too can rely on cached objects rather than creating new ones. Right now I have the following interfaces: IDataProvider is used to reach the database. It doesn't concern itself with the meaning of the objects it produces, but simply the way to produce them. interface IDataProvider{ // Select, Update, Create, et cetera access IEnumerable<Entry> GetEntries(); Entry GetEntryById(int id); } IDataManager is a layer that sits on top of the IDataProvider layer and manages the cache interface IDataManager : IDataProvider{ void ClearCache(); } Note that in practice the IDataManager implementation will have useful helper functions to add objects to their related cache stores. (In the future I may define other functions on the interface) I guess what I am looking for is the best way to approach a loop back from the IDataProvider implementations so that they can access the cache. Or a different approach entirely may be in order? I am not very interested in 3rd party products at the moment as I am interested in the design of these things much more than this specific implementation. Edit: I realize the title may be a bit misleading. I apologize for that... not sure what to call this question.

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  • NHibernate Many-to-Many Mapping not working

    - by ClutchDude
    I have a Nhibernate mapping file for a simple user/role mapping. Here are the mapping files: Users.hbm.xml <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Sample.Persistence" namespace="Sample.Persistence.Model"> <class name="User" table="Users"> <id name="UserKey"> <generator class="identity"/> </id> <property name="UserName" column="UserName" type="String" /> <property name="Password" column="Password" type="Byte[]" /> <property name="FirstName" column="FirstName" type="String" /> <property name="LastName" column="LastName" type="String" /> <property name="Email" column="Email" type="String" /> <property name="Active" column="Active" type="Boolean" /> <property name="Locked" column="Locked" type="Boolean" /> <property name="LoginFailures" column="LoginFailures" type="int" /> <property name="LockoutDate" column="LockoutDate" type="DateTime" generated="insert" /> <property name="Expired" column="Expired" type="Boolean" generated="insert"/> <set name="Roles" table="UsersRolesBridge" lazy="false"> <key column="UserKey" /> <many-to-many class="Role" not-found="exception" column="RoleKey" /> </set> </class> </hibernate-mapping> Role.hbm.xml <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="Sample.Persistence" namespace="Sample.Persistence.Model"> <class name="Role" table="Roles"> <id name="RoleKey"> <generator class="identity"/> </id> <property name="Name" column="Name" type="String" /> <set name="Users" inverse="true" atable="UsersRolesBridge" lazy="false" > <key column="RoleKey" /> <many-to-many class="User" column="UserKey" /> </set> </class> </hibernate-mapping> I am able to retrieve roles for each user via NHibernate but when I go to save a new object, the roles are not saved in the Bridge table. The user is created and insert with no issues. I've checked that the Role collection, a field on the user, is being populated with the proper rolekey before the Session.Save() is called. There is no exception thrown as well.

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  • get renamed file names of multiple upload form [js array] in codeigniter

    - by artmania
    Hi friends, I use codeigniter. I have a multiple image upload form. The code below is working well for uploading, but I also need to save file names to database. How can I get the names in here? I spent hours & hours :/ but could not sort it :/ Appreciate helps!!! uploadform.php echo form_open_multipart('gallery/upload'); <input type="file" name="photo" size="50" /> <input type="file" name="thumb" size="50" /> <input type="submit" value="Upload" /> </form> I have a controller between form view and model load model (of course : )) but didnt post here because of no need. gallery_model.php function multiple_upload($upload_dir = 'uploads/', $config = array()) { /* Upload */ $CI =& get_instance(); $files = array(); if(empty($config)) { $config['upload_path'] = realpath($upload_dir); $config['allowed_types'] = 'gif|jpg|jpeg|jpe|png'; $config['max_size'] = '2048'; } $CI->load->library('upload', $config); $errors = FALSE; foreach($_FILES as $key => $value) { if( ! empty($value['name'])) { if( ! $CI->upload->do_upload($key)) { $data['upload_message'] = $CI->upload->display_errors(ERR_OPEN, ERR_CLOSE); // ERR_OPEN and ERR_CLOSE are error delimiters defined in a config file $CI->load->vars($data); $errors = TRUE; } else { // Build a file array from all uploaded files $files[] = $CI->upload->data(); } } } // There was errors, we have to delete the uploaded files if($errors) { foreach($files as $key => $file) { @unlink($file['full_path']); } } elseif(empty($files) AND empty($data['upload_message'])) { $CI->lang->load('upload'); $data['upload_message'] = ERR_OPEN.$CI->lang->line('upload_no_file_selected').ERR_CLOSE; $CI->load->vars($data); } else { return $files; } /* ------------------------------- Insert to database */ // problem is here, i need file names to add db. // if there is already same names file at the folder, it rename file itself. so in such case, I need renamed file name :/ } }

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  • How to create XSD schema from XML with this kind of structure (in .net)?

    - by Mr. Brownstone
    Here's the problem: my input is XML file that looks something like: <BaseEntityClassInfo> <item> <key>BaseEntityClassInfo.SomeField</key> <value>valueData1</value> </item> <item> <key>BaseEntityClassInfo.AdditionalDataClass.SomeOtherField</key> <value>valueData2</value> </item> <item> <key>BaseEntityClassInfo.AdditionalDataClass.AnotherClassInfo.DisplayedText</key> <value>valueData3</value> </item> ... ... </BaseEntityClassInfo> The <key> element somehow describes entity classes fields and relationships (used in some other app that I don't have access to) and the <value> stores the actual data that I need. My goal is to programatically generate a typed Dataset from this XML that could then be used for creating reports. I thought of building some XSD schema from input XML file first and then use this schema to generate Dataset but I'm not sure how to do that. The problem is that I don't want all data in one table, I need several tables with relationships based on the <key> value so I guess I need to infer relational structure from XML <key> data in some way. So what do you think? How could this be done and what would be the best approach? Any advice, ideas, suggestions would be appreciated!

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  • Why can I not access this class member in python?

    - by Peter Smit
    I have the following code class Transcription(object): WORD = 0 PHONE = 1 STATE = 2 def __init__(self): self.transcriptions = [] def align_transcription(self,model,target=Transcription.PHONE): pass The important part here is that I would like to have a class member as default value for a variable. This however gives the following error: NameError: name 'Transcription' is not defined Why is this not possible and what is the right (pythonic) way to do something like this.

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  • Django 5 star Reviews

    - by firststepofthejourney
    Hello All, I am new to programming and I just jumped in to Django and I need a bit of help. I downloaded the generic reviews model off of Google code and I have no clue how to implement it. Can anyone pass along some guidance on how to make this work with a 5 star ratings system? I would appreciate it. Thanks.

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  • How to cutomize a modelform widget in django 1.1?

    - by muudscope
    I'm trying to modify a django form to use a textarea instead of a normal input for the "address" field in my house form. The docs seem to imply this changed from django 1.1 (which I'm using) to 1.2. But neither approach is working for me. Here's what I've tried: class HouseForm(forms.ModelForm): address = forms.Textarea() # Should work with django 1.1, but doesn't class Meta: model = House #widgets = { 'address': forms.Textarea() } # 1.2 style - doesn't work either.

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  • Grails query not using GORM

    - by Tihom
    What is the best way to query for something without using GORM in grails? I have query that doesn't seem to fit in the GORM model, the query has a subquery and a computed field. I posted on stackoverflow already with no response so I decided to take a different approach. I want to query for something not using GORM within a grails application. Is there an easy way to get the connection and go through the result set?

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  • Performance of Multiple Joins

    - by geeko
    Greetings Overflowers, I need to query against objects with many/complex spacial conditions. In relational databases that is translated to many joins (possibly 10+). I'm new to this business and wondering whether to go with MS SQL Server 2008 R2 or Oracle 11g or document-based solutions such as RavenDB or simply go with some spacial database (GIS)... Any thoughts ? Regards UPDATE: Thank you all for your answers. Would anybody opt for document/spatial databases ? My database would consist of tens of millions to few billion records. Mostly read-only. Almost no updates unless in case of mistakes in input. Overnight inserts and not that frequent. The join tables are predicted beforehand but the number of self joins (tables joining themselves multiple times) is not. Small pages of results from such queries are going to be viewed on an highly interactive website so response time is critical. Any predictions on how this can perform on MS SQL Server 2008 R2 or Oracle 11g ? I'm also concerned about boosting performance by adding more servers, which one scales better ? How about PostgresQL ?

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  • How to give the First image in a gallery a different class than the rest of the images - Carrierwave

    - by ChrisBedoya
    I have a model called "Photo" that belongs to a model called "Shoe". I using Carrierwave to upload multiple images. index.html.erb <% shoes.each do |shoe| %> <div class="shoe"> <div class="gallery"> <% shoe.photos.each do |photo| %> <%= link_to image_tag(photo.photo_file.url(:thumb).to_s), photo.photo_file.url.to_s, :class => 'fancybox', :rel => 'gallery' %> <% end %> </div> </div> <% end %> Outputs this: <div class="shoe"> <div class="gallery"> <a class="fancybox" href="../nike-kd-6-meteorology-2.jpg" rel="gallery"> <img src="../thumb_nike-kd-6-meteorology-2.jpg"> </a> <a class="fancybox" href="../nike-kd-6-meteorology-2.jpg" rel="gallery"> <img src="../thumb_nike-kd-6-meteorology-2.jpg"> </a> <a class="fancybox" href="../nike-kd-6-meteorology-2.jpg" rel="gallery"> <img src="../thumb_nike-kd-6-meteorology-2.jpg"> </a> </div> </div> But I want the first image of each gallery to be able to have its own class and the rest of the images to have their own class. Something like this: <a class="firstclass" href="../nike-kd-6-meteorology-2.jpg" rel="gallery"> <img src="../thumb_nike-kd-6-meteorology-2.jpg"> </a> <a class="fancybox" href="../nike-kd-6-meteorology-2.jpg" rel="gallery"> <img src="../thumb_nike-kd-6-meteorology-2.jpg"> </a> <a class="fancybox" href="../nike-kd-6-meteorology-2.jpg" rel="gallery"> <img src="../thumb_nike-kd-6-meteorology-2.jpg"> </a> How can I do this? Also I want each gallery to have its own unique id but when I try to add this: :rel => 'gallery<%= shoe.id %>' I get a Syntax error. Thanks.

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  • How to check which action method rendered the current view (from within the current view) ?

    - by Richard77
    Hello, I would like to know how to check which action displayed the current View (from the current view). For instance, to check if controller myController originated the rendering (I guess) I can write: <% if(ViewContext.Controller is myApplication.Controllers.myController)%> In fact, I want to use the same View model for 2 actions methods, like this: <% If( First Action rendered this view){%> // Display this <%} else {%> //Display that <%}%> Thanks for helping

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  • how to send some data to the Thread module on python and google-map-engine

    - by zjm1126
    from google.appengine.ext import db class Log(db.Model): content = db.StringProperty(multiline=True) class MyThread(threading.Thread): def run(self,request): #logs_query = Log.all().order('-date') #logs = logs_query.fetch(3) log=Log() log.content=request.POST.get('content',None) log.put() def Log(request): thr = MyThread() thr.start(request) return HttpResponse('') error is : Exception in thread Thread-1: Traceback (most recent call last): File "D:\Python25\lib\threading.py", line 486, in __bootstrap_inner self.run() File "D:\zjm_code\helloworld\views.py", line 33, in run log.content=request.POST.get('content',None) NameError: global name 'request' is not defined

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  • jRuby's Float to represent in JTable's cell

    - by guai
    Hello. I need to represent floats in jTable formatted. When I do tbl.model.add_row [obj, 1.3524632478].to_java, obj is represented as it's to_s method's return value, but float do not. Overriding float's to_s method does nothing. I want floats to be formatted like this class Float def to_s sprintf("%.2f", self) end end in all my tables.

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  • Are there good reasons not to use an ORM?

    - by hangy
    During my apprenticeship, I have used NHibernate for some smaller projects which I mostly coded and designed on my own. Now, before starting some bigger project, the discussion arose how to design data access and whether or not to use an ORM layer. As I am still in my apprenticeship and still consider myself a beginner in enterprise programming, I did not really try to push in my opinion, which is that using an object relational mapper to the database can ease development quite a lot. The other coders in the development team are much more experienced than me, so I think I will just do what they say. :-) However, I do not completely understand two of the main reasons for not using NHibernate or a similar project: One can just build one’s own data access objects with SQL queries and copy those queries out of Microsoft SQL Server Management Studio. Debugging an ORM can be hard. So, of course I could just build my data access layer with a lot of SELECTs etc, but here I miss the advantage of automatic joins, lazy-loading proxy classes and a lower maintenance effort if a table gets a new column or a column gets renamed. (Updating numerous SELECT, INSERT and UPDATE queries vs. updating the mapping config and possibly refactoring the business classes and DTOs.) Also, using NHibernate you can run into unforeseen problems if you do not know the framework very well. That could be, for example, trusting the Table.hbm.xml where you set a string’s length to be automatically validated. However, I can also imagine similar bugs in a “simple” SqlConnection query based data access layer. Finally, are those arguments mentioned above really a good reason not to utilise an ORM for a non-trivial database based enterprise application? Are there probably other arguments they/I might have missed? (I should probably add that I think this is like the first “big” .NET/C# based application which will require teamwork. Good practices, which are seen as pretty normal on Stack Overflow, such as unit testing or continuous integration, are non-existing here up to now.)

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  • improve javascript prototypal inheritance

    - by Julio
    I'm using a classical javascript prototypal inheritance, like this: function Foo() {} Naknek.prototype = { //Do something }; var Foo = window.Foo = new Foo(); I want to know how I can improve this and why I can't use this model: var Foo = window.Foo = new function() { }; Foo.prototype = { //Do something }; Why this code doesn't work? In my head this is more logical than the classical prototypal inheritance.

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  • How can I use rows in a lookup table as columns in a MySQL query?

    - by TomH
    I'm trying to build a MySQL query that uses the rows in a lookup table as the columns in my result set. LookupTable id | AnalysisString 1 | color 2 | size 3 | weight 4 | speed ScoreTable id | lookupID | score | customerID 1 | 1 | A | 1 2 | 2 | C | 1 3 | 4 | B | 1 4 | 2 | A | 2 5 | 3 | A | 2 6 | 1 | A | 3 7 | 2 | F | 3 I'd like a query that would use the relevant lookupTable rows as columns in a query so that I can get a result like this: customerID | color | size | weight | speed 1 A C D 2 A A 3 A F The kicker of the problem is that there may be additional rows added to the LookupTable and the query should be dynamic and not have the Lookup IDs hardcoded. That is, this will work: SELECT st.customerID, (SELECT st1.score FROM ScoreTable st1 WHERE lookupID=1 AND st.customerID = st1.customerID) AS color, (SELECT st1.score FROM ScoreTable st1 WHERE lookupID=2 AND st.customerID = st1.customerID) AS size, (SELECT st1.score FROM ScoreTable st1 WHERE lookupID=3 AND st.customerID = st1.customerID) AS weight, (SELECT st1.score FROM ScoreTable st1 WHERE lookupID=4 AND st.customerID = st1.customerID) AS speed FROM ScoreTable st GROUP BY st.customerID Until there is a fifth row added to the LookupTable . . . Perhaps I'm breaking the whole relational model and will have to resolve this in the backend PHP code? Thanks for pointers/guidance. tom

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  • T-SQL generated from LINQ to SQL is missing a where clause

    - by Jimmy W
    I have extended some functionality to a DataContext object (called "CodeLookupAccessDataContext") such that the object exposes some methods to return results of LINQ to SQL queries. Here are the methods I have defined: public List<CompositeSIDMap> lookupCompositeSIDMap(int regionId, int marketId) { var sidGroupId = CompositeSIDGroupMaps.Where(x => x.RegionID.Equals(regionId) && x.MarketID.Equals(marketId)) .Select(x => x.CompositeSIDGroup); IEnumerator<int> sidGroupIdEnum = sidGroupId.GetEnumerator(); if (sidGroupIdEnum.MoveNext()) return lookupCodeInfo<CompositeSIDMap, CompositeSIDMap>(x => x.CompositeSIDGroup.Equals(sidGroupIdEnum.Current), x => x); else return null; } private List<TResult> lookupCodeInfo<T, TResult>(Func<T, bool> compLambda, Func<T, TResult> selectLambda) where T : class { System.Data.Linq.Table<T> dataTable = this.GetTable<T>(); var codeQueryResult = dataTable.Where(compLambda) .Select(selectLambda); List<TResult> codeList = new List<TResult>(); foreach (TResult row in codeQueryResult) codeList.Add(row); return codeList; } CompositeSIDGroupMap and CompositeSIDMap are both tables in our database that are represented as objects in my DataContext object. I wrote the following code to call these methods and display the T-SQL generated after calling these methods: using (CodeLookupAccessDataContext codeLookup = new CodeLookupAccessDataContext()) { codeLookup.Log = Console.Out; List<CompositeSIDMap> compList = codeLookup.lookupCompositeSIDMap(5, 3); } I got the following results in my log after invoking this code: SELECT [t0].[CompositeSIDGroup] FROM [dbo].[CompositeSIDGroupMap] AS [t0] WHERE ([t0].[RegionID] = @p0) AND ([t0].[MarketID] = @p1) -- @p0: Input Int (Size = 0; Prec = 0; Scale = 0) [5] -- @p1: Input Int (Size = 0; Prec = 0; Scale = 0) [3] -- Context: SqlProvider(Sql2005) Model: AttributedMetaModel Build: 3.5.30729.1 SELECT [t0].[PK_CSM], [t0].[CompositeSIDGroup], [t0].[InputSID], [t0].[TargetSID], [t0].[StartOffset], [t0].[EndOffset], [t0].[Scale] FROM [dbo].[CompositeSIDMap] AS [t0] -- Context: SqlProvider(Sql2005) Model: AttributedMetaModel Build: 3.5.30729.1 The first T-SQL statement contains a where clause as specified and returns one column as expected. However, the second statement is missing a where clause and returns all columns, even though I did specify which rows I wanted to view and which columns were of interest. Why is the second T-SQL statement generated the way it is, and what should I do to ensure that I filter out the data according to specifications via the T-SQL? Also note that I would prefer to keep lookupCodeInfo() and especially am interested in keeping it enabled to accept lambda functions for specifying which rows/columns to return.

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