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• CodePlex Daily Summary for Tuesday, August 19, 2014

  CodePlex Daily Summary for Tuesday, August 19, 2014Popular ReleasesVG-Ripper & PG-Ripper: VG-Ripper 2.9.62: changes NEW: Added Support for 'MadImage.org' links NEW: Added Support for 'ImgSpot.org' links NEW: Added Support for 'ImgClick.net' links NEW: Added Support for 'Imaaage.com' links NEW: Added Support for 'Image-Bugs.com' links NEW: Added Support for 'Pictomania.org' links NEW: Added Support for 'ImgDap.com' links NEW: Added Support for 'FileSpit.com' links FIXED: 'ImgSee.me' linksLinq 4 Javascript: Version 2.4: Minor Changes Made Added Count() and Count(with where clause) Distinct will now use a dictionary instead of a custom dictionary object Organize the unit tests. The variable names will actually make sense and won't be 2 letters. SelectMany will now use the queryable logic.Magick.NET: Magick.NET 7.0.0.0001: Magick.NET linked with ImageMagick 7-Beta.CMake Tools for Visual Studio: CMake Tools for Visual Studio 1.2: This release adds the following new features and bug fixes from CMake Tools for Visual Studio 1.1: Added support for CMake 3.0. Added support for word completion. Added IntelliSense support for the CMAKEHOSTSYSTEM_INFORMATION command. Fixed syntax highlighting for tokens beginning with escape sequences. Fixed issue uninstalling CMake Tools for Visual Studio after Visual Studio has been uninstalled.GW2 Personal Assistant Overlay: GW2 Personal Assistant Overlay 1.1: Overview1.1 is the second 'stable' release of the GW2 Personal Assistant Overlay. This version includes just a couple of very minor features and some minor bug fixes. For details regarding installation, setup, and general use, see Documentation. Note: If you were using a previous version, you will probably want to copy over the following user settings files: GW2PAO.DungeonSettings.xml GW2PAO.EventSettings.xml GW2PAO.WvWSettings.xml GW2PAO.ZoneCompletionSettings.xml New FeaturesAdded new "No...OpenCppCoverage: OpenCppCoverage 0.9.1: - Add Jenkins support. - Command line argument can be placed inside a config file. If you do not have Visual Studio C++ 2013 you need to download redistributable packages: http://www.microsoft.com/en-us/download/details.aspx?id=40784Easy Backup Windows Service: Release 2.0 with CU: Fix log error when "To" directory not exist in fyle system. Force run program as administrator by default. Add 'everyday' schedule element. Update solution to VS 2013.Easy Backup Application: Release 2.0 with CU: Fix log error when "To" directory not exist in fyle system. Fix app location initialization. Force run program as administrator by default. Update solution to VS 2013.TEBookConverter: 1.5: Added: Turkish and French translations Added: A few interface changes Removed: SkinDynamulet: Dynamulet v0.1: DynamoDB Transaction Server v0.1Console parallel nunit tests runner: ConsoleUnitTestsRunner 1.03: bugfixingFluentx: Fluentx v1.5.3: Added few more extension methods.fastJSON: v2.1.2: 2.1.2 - bug fix circular referencesJPush.NET: JPush Server SDK 1.2.1 (For JPush V3): Assembly: 1.2.1.24728 JPush REST API Version: v3 JPush Documentation Reference .NET framework: v4.0 or above. Sample: class: JPushClientV3 2014 Augest 15th.SEToolbox: SEToolbox 01.043.008 Release 1: Changed ship/station names to use new DisplayName instead of Beacon/Antenna. Fixed issue with updated SE binaries 01.043.018 using new Voxel Material definitions.Google .Net API: Drive.Sample: Google .NET Client API – Drive.SampleInstructions for the Google .NET Client API – Drive.Sample</h2> http://code.google.com/p/google-api-dotnet-client/source/browse/?repo=samples#hg%2FDrive.SampleBrowse Source, or main file http://code.google.com/p/google-api-dotnet-client/source/browse/Drive.Sample/Program.cs?repo=samplesProgram.cs <h3>1. Checkout Instructions</h3> <p><b>Prerequisites:</b> Install Visual Studio, and <a href="http://mercurial.selenic.com/">Mercurial</a>.</p> ...FineUI - jQuery / ExtJS based ASP.NET Controls: FineUI v4.1.1: -??Form??????????????（???-5929）。 -?TemplateField??ExpandOnDoubleClick、ExpandOnEnter、ExpandToSelectRow????（LZOM-5932）。 -BodyPadding???????，??“5”“5 10”，???????????“5px”“5px 10px”。 -??TriggerBox?EnableEdit=false????，??????????????（Jango_Jing-5450）。 -???????????DataKeyNames???????????（yygy-6002）。 -????????????????????????（Gnid-6018）。 -??PageManager???AutoSizePanelID????，??????????????????（yygy-6008）。 -?FState???????????????，????????????????（????-5925）。 -??????OnClientClick???return?????????（FineU...DNN CMS Platform: 07.03.02: Major Highlights Fixed backwards compatibility issue with 3rd party control panels Fixed issue in the drag and drop functionality of the File Uploader in IE 11 and Safari Fixed issue where users were able to create pages with the same name Fixed issue that affected older versions of DNN that do not include the maxAllowedContentLength during upgrade Fixed issue that stopped some skins from being upgraded to newer versions Fixed issue that randomly showed an unexpected error during us...WordMat: WordMat for Mac: WordMat for Mac has a few limitations compared to the Windows version - Graph is not supported (Gnuplot, GeoGebra and Excel works) - Units are not supported yet (Coming up) The Mac version is yet as tested as the windows version.MFCMAPI: August 2014 Release: Build: 15.0.0.1042 Full release notes at SGriffin's blog. If you just want to run the MFCMAPI or MrMAPI, get the executables. If you want to debug them, get the symbol files and the source. The 64 bit builds will only work on a machine with Outlook 2010/2013 64 bit installed. All other machines should use the 32 bit builds, regardless of the operating system. Facebook BadgeNew Projectsangle.works: Angle.works sample solutionAutomatically Update CMS from SCOM: Microsoft Central Management Server (CMS) was released with SQL Server 2008; however keeping the server list up-to-date is challenging.BLE for NETMF: Class library targeted to .NET Micro Framework for BLE support (both central and peripheral profiles).CIIS: ciisClipboard Calculator: Simple tool to calculate numbers from the clipboard. Useful for SQL Server Management Studio User.CYCLOPS: CYCLOPS is a project that seeks to aid the development and testing of ANPR software. CYCLOPS provides a virtual camera and virtual frame grabber for image procedemo4: demo4eAsset: Web based Fixed Asset Management SystemEFML-Runtime: Create applications with xml,css,js feeadmin: Complete fee managementFinal Fantasy VI Randomizer: This is a simple program that randomizes skills, items, and characters in Final Fantasy VI. It is used for racing the game.Object Editor: Object Editor is a visual editor which allows to edit any properties of any class and to simplify the changing and displaying of a class instance.pbb: Pinoy Badminton Buddies Web ApplicationRubyFeed: RubyFeed is a stand-alone HTML5 page for Internet Explorer on Windows 8 and above that makes it easy to view and manage your Windows RSS Platform feeds.

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• Stop lazy loading or skip loading a property in NHibernate? Proxy cannot be serialized through WCF

  - by HelloSam

  Consider I have a parent, child relationship class and mapping. I am using NHibernate to read the object from the database, and intended to use WCF to send the object across the wire. Goal For reading the parent object, I want to selectively, at different execution path, decide when I would want to load the child object. Because I don't want to read more than what I needed. Those partially loaded object must be able to sent through WCF. When I mean I don't load it, neither side will access such property. Problem When such partially loaded object is being sent through WCF, as those property is marked as [DataContract], it cannot be serialized as the property is lazy load proxy instead of real known type. What I want to archive, or solution that I can think of lazy=false or lazy=true doesn't work. Former will eagerly fetch all the relationships, latter will create a proxy. But I want nothing instead - a null would be the best. I don't need lazy load. I hope to get a null for those references that I don't want to fetch. A null, but not just a proxy. This will makes WCF happy, and waste less time to have a lazy-load proxy constructed. Like could I have a null proxy factory? -OR- Or making WCF ignoring those property that's a proxy instead of real. I tried the IDataContractSurrogate solution, but only parent is passed to GetObjectToSerialize, I never observe an proxy being passed through GetObjectToSerialize, leaving no chance to un-proxy it. Edit After reading the comments, more surfing on the Internet... It seems to me that DTO would shift major part of the computation to the server side. But for the project I am working on, 50% of time the client is "smarter" than the server and the server is more like a data store with validation and verification. Though I agree the server is not exactly dumb - I have to decide when to fetch the extra references already, and DTO will make this very explicit. Maybe I should just take the pain. I didn't know http://automapper.codeplex.com/ before, this motivates me a little more to take the pain. On the other hand, I found http://trentacular.com/2009/08/how-to-use-nhibernate-lazy-initializing-proxies-with-web-services-or-wcf/, which seems to be working with IDataContractSurrogate.GetObjectToSerialize.

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• ASP.NET MVC 2: Updating a Linq-To-Sql Entity with an EntitySet

  - by Simon

  I have a Linq to Sql Entity which has an EntitySet. In my View I display the Entity with it's properties plus an editable list for the child entites. The user can dynamically add and delete those child entities. The DefaultModelBinder works fine so far, it correctly binds the child entites. Now my problem is that I just can't get Linq To Sql to delete the deleted child entities, it will happily add new ones but not delete the deleted ones. I have enabled cascade deleting in the foreign key relationship, and the Linq To Sql designer added the "DeleteOnNull=true" attribute to the foreign key relationships. If I manually delete a child entity like this: myObject.Childs.Remove(child); context.SubmitChanges(); This will delete the child record from the DB. But I can't get it to work for a model binded object. I tried the following: // this does nothing public ActionResult Update(int id, MyObject obj) // obj now has 4 child entities { var obj2 = _repository.GetObj(id); // obj2 has 6 child entities if(TryUpdateModel(obj2)) //it sucessfully updates obj2 and its childs { _repository.SubmitChanges(); // nothing happens, records stay in DB } else ..... return RedirectToAction("List"); } and this throws an InvalidOperationException, I have a german OS so I'm not exactly sure what the error message is in english, but it says something along the lines of that the entity needs a Version (Timestamp row?) or no update check policies. I have set UpdateCheck="Never" to every column except the primary key column. public ActionResult Update(MyObject obj) { _repository.MyObjectTable.Attach(obj, true); _repository.SubmitChanges(); // never gets here, exception at attach } I've read alot about similar "problems" with Linq To Sql, but it seems most of those "problems" are actually by design. So am I right in my assumption that this doesn't work like I expect it to work? Do I really have to manually iterate through the child entities and delete, update and insert them manually? For such a simple object this may work, but I plan to create more complex objects with nested EntitySets and so on. This is just a test to see what works and what not. So far I'm disappointed with Linq To Sql (maybe I just don't get it). Would be the Entity Framework or NHibernate a better choice for this scenario? Or would I run into the same problem?

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• Cross-table linq query with EF4/POCO

  - by Basiclife

  Hi All, I'm new to EF(any version) and POCO. I'm trying to use POCO entities with a generic repository in a "code-first" mode(?) I've got some POCO Entities (no proxies, no lazy loading, nothing). I have a repository(of T as Entity) which provides me with basic get/getsingle/getfirst functionality which takes a lambda as a parameter (specifically a System.Func(Of T, Boolean)) Now as I'm returning the simplest possible POCO object, none of the relationship parameters work once they've been retrieved from the database (as I would expect). However, I had assumed (wrongly) that my lambda query passed to the repository would be able to use the links between entities as it would be executed against the DB before the simple POCO entities are generated. The flow is: GUI calls: Public Function GetAllTypesForCategory(ByVal CategoryID As Guid) As IEnumerable(Of ItemType) Return ItemTypeRepository.Get(Function(x) x.Category.ID = CategoryID) End Function Get is defined in Repository(of T as Entity): Public Function [Get](ByVal Query As System.Func(Of T, Boolean)) As IEnumerable(Of T) Implements Interfaces.IRepository(Of T).Get Return ObjectSet.Where(Query).ToList() End Function The code doesn't error when this method is called but does when I try to use the result set. (This seems to be a lazy loading behaviour so I tried adding the .ToList() to force eager loading - no difference) I'm using unity/IOC to wire it all up but I believe that's irrelevant to the issue I'm having NB: Relationships between entities are being configured properly and if I turn on proxies/lazy loading/etc... this all just works. I'm intentionally leaving all that turned off as some calls to the BL will be from a website but some will be via WCF - So I want the simplest possible objects. Also, I don't want a change in an object passed to the UI to be committed to the DB if another BL method calls Commit() Can someone please either point out how to make this work or explain why it's not possible? All I want to do is make sure the lambda I pass in is performed against the DB before the results are returned Many thanks. In case it matters, the container is being populated with everything as shown below: Container.AddNewExtension(Of EFRepositoryExtension)() Container.Configure(Of IEFRepositoryExtension)(). WithConnection(ConnectionString). WithContextLifetime(New HttpContextLifetimeManager(Of IObjectContext)()). ConfigureEntity(New CategoryConfig(), "Categories"). ConfigureEntity(New ItemConfig()). ... )

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• Importing a large dataset into a database

  - by peaceful

  I'm a beginning programmer in the relevant areas to this question, so if possible, it'd be helpful to avoid assuming I know a lot already. I'm trying to import the OpenLibrary dataset into a local Postgres database. After it's imported, I plan to use it as a starting seed for a Ruby on Rails application that will include information on books. The OpenLibrary datasets are available here, in a modified JSON format: http://openlibrary.org/dev/docs/jsondump I only need very basic information for my application, much less than what is provided in the dumps. I'm only trying to get out book titles, author names, and relationships between books and authors. Below are two typical entries from their dataset, the first for an author, and the second for a book (they seem to have an entry for each edition of a book). The entries seem to lead off with a primary key, and then with a type, before including the actual JSON database dump. /a/OL2A /type/author {"name": "U. Venkatakrishna Rao", "personal_name": "U. Venkatakrishna Rao", "last_modified": {"type": "/type/datetime", "value": "2008-09-10 08:44:01.978456"}, "key": "/a/OL2A", "birth_date": "1904", "type": {"key": "/type/author"}, "id": 99, "revision": 3} /b/OL345M /type/edition {"publishers": ["Social Science Research Project, Dept. of Geography, University of Dacca"], "pagination": "ii, 54 p.", "title": "Land use in Fayadabad area", "lccn": ["sa 65000491"], "subject_place": ["East Pakistan", "Dacca region."], "number_of_pages": 54, "languages": [{"comment": "initial import", "code": "eng", "name": "English", "key": "/l/eng"}], "lc_classifications": ["S471.P162 E23"], "publish_date": "1963", "publish_country": "pk ", "key": "/b/OL345M", "authors": [{"birth_date": "1911", "name": "Nafis Ahmad", "key": "/a/OL302A", "personal_name": "Nafis Ahmad"}], "publish_places": ["Dacca, East Pakistan"], "by_statement": "[by] Nafis Ahmad and F. Karim Khan.", "oclc_numbers": ["4671066"], "contributions": ["Khan, Fazle Karim, joint author."], "subjects": ["Land use -- East Pakistan -- Dacca region."]} The size of the uncompressed dumps are enormous, about 2GB for the authors list, and 18GB for the book editions list. OpenLibrary does not provide any tools for this themselves, they provide a simple unoptimized Python script for reading in sample data (which unlike the actual dumps comes in pure JSON format), but they estimate if that was modified for use on their actual data it would take 2 months (!) to finish loading the data. How can I read this into the database? I assume I'll need to write a program to do this. What language and any guidance on how I should do it to finish in a reasonable amount of time? The only scripting language I have any experience with is Ruby.

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• Deletes not cascading for self-referencing entities

  - by jwaddell

  I have the following (simplified) Hibernate entities: @Entity @Table(name = "package") public class Package { protected Content content; @OneToOne(cascade = {javax.persistence.CascadeType.ALL}) @JoinColumn(name = "content_id") @Fetch(value = FetchMode.JOIN) public Content getContent() { return content; } public void setContent(Content content) { this.content = content; } } @Entity @Table(name = "content") public class Content { private Set<Content> subContents = new HashSet<Content>(); private ArchivalInformationPackage parentPackage; @OneToMany(fetch = FetchType.EAGER) @JoinTable(name = "subcontents", joinColumns = {@JoinColumn(name = "content_id")}, inverseJoinColumns = {@JoinColumn(name = "elt")}) @Cascade(value = {org.hibernate.annotations.CascadeType.DELETE, org.hibernate.annotations.CascadeType.REPLICATE}) @Fetch(value = FetchMode.SUBSELECT) public Set<Content> getSubContents() { return subContents; } public void setSubContents(Set<Content> subContents) { this.subContents = subContents; } @ManyToOne(cascade = {CascadeType.ALL}) @JoinColumn(name = "parent_package_id") public Package getParentPackage() { return parentPackage; } public void setParentPackage(Package parentPackage) { this.parentPackage = parentPackage; } } So there is one Package, which has one "top" Content. The top Content links back to the Package, with cascade set to ALL. The top Content may have many "sub" Contents, and each sub-Content may have many sub-Contents of its own. Each sub-Content has a parent Package, which may or may not be the same Package as the top Content (ie a many-to-one relationship for Content to Package). The relationships are required to be ManyToOne (Package to Content) and ManyToMany (Content to sub-Contents) but for the case I am currently testing each sub-Content only relates to one Package or Content. The problem is that when I delete a Package and flush the session, I get a Hibernate error stating that I'm violating a foreign key constraint on table subcontents, with a particular content_id still referenced from table subcontents. I've tried specifically (recursively) deleting the Contents before deleting the Package but I get the same error. Is there a reason why this entity tree is not being deleted properly? EDIT: After reading answers/comments I realised that a Content cannot have multiple Packages, and a sub-Content cannot have multiple parent-Contents, so I have modified the annotations from ManyToOne and ManyToMany to OneToOne and OneToMany. Unfortunately that did not fix the problem. I have also added the bi-directional link from Content back to the parent Package which I left out of the simplified code.

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• Filter chain halted as [:login_required] rendered_or_redirected

  - by Magicked

  Hopefully I can explain this well enough, but please let me know if more information is needed! I'm building a form where a user can create an "incident". This incident has the following relationships: belongs_to: customer (customer has_many incidents) belongs_to: user (user has_many incidents) has_one: incident_status (incident_status belongs to incident) The form allows the user to assign the incident to a user (select form) and then select an incident status. The incident is nested in customer. However, I'm getting the following in the server logs: Processing IncidentsController#create (for 127.0.0.1 at 2010-04-26 10:41:33) [POST] Parameters: {"commit"=>"Create", "action"=>"create", "authenticity_token"=>"YhW++vd/dnLoNV/DSl1DULcaWq/RwP7jvLOVx9jQblA=", "customer_id"=>"4", "controller"=>"incidents", "incident"=>{"title"=>"Some Bad Incident", "incident_status_id"=>"1", "user_id"=>"2", "other_name"=>"SS01-042310-001"}} User Load (0.3ms) SELECT * FROM "users" WHERE ("users"."id" = 2) LIMIT 1 Redirected to http://localhost:3000/session/new Filter chain halted as [:login_required] rendered_or_redirected. Completed in 55ms (DB: 0) | 302 Found [http://localhost/customers/4/incidents] It looks to me like it's trying to gather information about the user, even though it already has the id (which is all it needs to create the incident), and the user may not have permission to do a select statement like that? I'm rather confused. Here is the relevant (I think) information in the Incident controller. before_filter :login_required, :get_customer def new @incident = @customer.incidents.build @users = @customer.users @statuses = IncidentStatus.find(:all) respond_to do |format| format.html # new.html.erb format.xml { render :xml => @incident } end end def create @incident = @customer.incidents.build(params[:incident]) respond_to do |format| if @incident.save flash[:notice] = 'Incident was successfully created.' format.html { redirect_to(@incident) } format.xml { render :xml => @incident, :status => :created, :location => @incident } else format.html { render :action => "new" } format.xml { render :xml => @incident.errors, :status => :unprocessable_entity } end end end Just as an FYI, I am using the restful_authentication plugin. So in summary, when I submit the incident creation form, it does not save the incident because it halts. I'm still very new to rails, so my skill at diagnosing problems like this is still very bad. I'm going in circles. :) Thanks in advance for any help. Please let me know if more information is needed and I'll edit it in!

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• Many-to-Many Relationship mapping does not trigger the EventListener OnPostInsert or OnPostDelete Ev

  - by san

  I'm doing my auditing using the Events listeners that nHibernate provides. It works fine for all mappings apart from HasmanyToMany mapping. My Mappings are as such: Table("Order"); Id(x => x.Id, "OrderId"); Map(x => x.Name, "OrderName").Length(150).Not.Nullable(); Map(x => x.Description, "OrderDescription").Length(800).Not.Nullable(); Map(x => x.CreatedOn).Not.Nullable(); Map(x => x.CreatedBy).Length(70).Not.Nullable(); Map(x => x.UpdatedOn).Not.Nullable(); Map(x => x.UpdatedBy).Length(70).Not.Nullable(); HasManyToMany(x => x.Products) .Table("OrderProduct") .ParentKeyColumn("OrderId") .ChildKeyColumn("ProductId") .Cascade.None() .Inverse() .AsSet(); Table("Product"); Id(x => x.Id, "ProductId"); Map(x => x.ProductName).Length(150).Not.Nullable(); Map(x => x.ProductnDescription).Length(800).Not.Nullable(); Map(x => x.Amount).Not.Nullable(); Map(x => x.CreatedOn).Not.Nullable(); ; Map(x => x.CreatedBy).Length(70).Not.Nullable(); Map(x => x.UpdatedOn).Not.Nullable(); Map(x => x.UpdatedBy).Length(70).Not.Nullable(); HasManyToMany(x => x.Orders) .Table("OrderProduct") .ParentKeyColumn("ProductId") .ChildKeyColumn("OrderId") .Cascade.None() .AsSet(); Whenever I do an update of an order (Eg: Changed the Orderdescription and deleted one of the products associated with it) It works fine as in it updated the order table and deletes the row in the orderproduct table. the event listener that I have associated with it captures the update of the order table but does NOT capture the associated delete event when the orderproduct is deleted. This behaviour is observed only in case of a ManyTomany mapped relationships. Since I would also like audit the packageproduct deletion, its kind of an annoyance when the event listener aren't able to capture the delete event. Any information about it would be greatly appreciated.

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• How to optimize Core Data query for full text search

  - by dk

  Can I optimize a Core Data query when searching for matching words in a text? (This question also pertains to the wisdom of custom SQL versus Core Data on an iPhone.) I'm working on a new (iPhone) app that is a handheld reference tool for a scientific database. The main interface is a standard searchable table view and I want as-you-type response as the user types new words. Words matches must be prefixes of words in the text. The text is composed of 100,000s of words. In my prototype I coded SQL directly. I created a separate "words" table containing every word in the text fields of the main entity. I indexed words and performed searches along the lines of SELECT id, * FROM textTable JOIN (SELECT DISTINCT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) ON id=textTableId LIMIT 50 This runs very fast. Using an IN would probably work just as well, i.e. SELECT * FROM textTable WHERE id IN (SELECT textTableId FROM words WHERE word BETWEEN 'foo' AND 'fooz' ) LIMIT 50 The LIMIT is crucial and allows me to display results quickly. I notify the user that there are too many to display if the limit is reached. This is kludgy. I've spent the last several days pondering the advantages of moving to Core Data, but I worry about the lack of control in the schema, indexing, and querying for an important query. Theoretically an NSPredicate of textField MATCHES '.*\bfoo.*' would just work, but I'm sure it will be slow. This sort of text search seems so common that I wonder what is the usual attack? Would you create a words entity as I did above and use a predicate of "word BEGINSWITH 'foo'"? Will that work as fast as my prototype? Will Core Data automatically create the right indexes? I can't find any explicit means of advising the persistent store about indexes. I see some nice advantages of Core Data in my iPhone app. The faulting and other memory considerations allow for efficient database retrievals for tableview queries without setting arbitrary limits. The object graph management allows me to easily traverse entities without writing lots of SQL. Migration features will be nice in the future. On the other hand, in a limited resource environment (iPhone) I worry that an automatically generated database will be bloated with metadata, unnecessary inverse relationships, inefficient attribute datatypes, etc. Should I dive in or proceed with caution?

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• How to eager load sibling data using LINQ to SQL?

  - by Scott

  The goal is to issue the fewest queries to SQL Server using LINQ to SQL without using anonymous types. The return type for the method will need to be IList<Child1>. The relationships are as follows: Parent Child1 Child2 Grandchild1 Parent Child1 is a one-to-many relationship Child1 Grandchild1 is a one-to-n relationship (where n is zero to infinity) Parent Child2 is a one-to-n relationship (where n is zero to infinity) I am able to eager load the Parent, Child1 and Grandchild1 data resulting in one query to SQL Server. This query with load options eager loads all of the data, except the sibling data (Child2): DataLoadOptions loadOptions = new DataLoadOptions(); loadOptions.LoadWith<Child1>(o => o.GrandChild1List); loadOptions.LoadWith<Child1>(o => o.Parent); dataContext.LoadOptions = loadOptions; IQueryable<Child1> children = from child in dataContext.Child1 select child; I need to load the sibling data as well. One approach I have tried is splitting the query into two LINQ to SQL queries and merging the result sets together (not pretty), however upon accessing the sibling data it is lazy loaded anyway. Adding the sibling load option will issue a query to SQL Server for each Grandchild1 and Child2 record (which is exactly what I am trying to avoid): DataLoadOptions loadOptions = new DataLoadOptions(); loadOptions.LoadWith<Child1>(o => o.GrandChild1List); loadOptions.LoadWith<Child1>(o => o.Parent); loadOptions.LoadWith<Parent>(o => o.Child2List); dataContext.LoadOptions = loadOptions; IQueryable<Child1> children = from child in dataContext.Child1 select child; exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=1 exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=2 exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=3 exec sp_executesql N'SELECT * FROM [dbo].[Child2] AS [t0] WHERE [t0].[ForeignKeyToParent] = @p0',N'@p0 int',@p0=4 I've also written LINQ to SQL queries to join in all of the data in hopes that it would eager load the data, however when the LINQ to SQL EntitySet of Child2 or Grandchild1 are accessed it lazy loads the data. The reason for returning the IList<Child1> is to hydrate business objects. My thoughts are I am either: Approaching this problem the wrong way. Have the option of calling a stored procedure? My organization should not be using LINQ to SQL as an ORM? Any help is greatly appreciated. Thank you, -Scott

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• redoing object model construction to fit with asynchronous data fetching

  - by Andrew Patterson

  I have a modeled a set of objects that correspond with some real world concepts. TradeDrug, GenericDrug, TradePackage, DrugForm Underlying the simple object model I am trying to provide is a complex medical terminology that uses numeric codes to represent relationships and concepts, all accessible via a REST service - I am trying to hide away some of that complexity with an object wrapper. To give a concrete example I can call TradeDrug d = Searcher.FindTradeDrug("Zoloft") or TradeDrug d = new TradeDrug(34) where 34 might be the code for Zoloft. This will consult a remote server to find out some details about Zoloft. I might then call GenericDrug generic = d.EquivalentGeneric() System.Out.WriteLine(generic.ActiveIngredient().Name) in order to get back the generic drug sertraline as an object (again via a background REST call to the remote server that has all these drug details), and then perhaps find its ingredient. This model works fine and is being used in some applications that involve data processing. Recently however I wanted to do a silverlight application that used and displayed these objects. The silverlight environment only allows asynchronous REST/web service calls. I have no problems with how to make the asychhronous calls - but I am having trouble with what the design should be for my object construction. Currently the constructors for my objects do some REST calls sychronously. public TradeDrug(int code) { form = restclient.FetchForm(code) name = restclient.FetchName(code) etc.. } If I have to use async 'events' or 'actions' in order to use the Silverlight web client (I know silverlight can be forced to be a synchronous client but I am interested in asychronous approaches), does anyone have an guidance or best practice for how to structure my objects. I can pass in an action callback to the constructor public TradeDrug(int code, Action<TradeDrug> constructCompleted) { } but this then allows the user to have a TradeDrug object instance before what I want to construct is actually finished. It also doesn't support an 'event' async pattern because the object doesn't exist to add the event to until it is constructed. Extending that approach might be a factory object that itself has an asynchronous interface to objects factory.GetTradeDrugAsync(code, completedaction) or with a GetTradeDrugCompleted event? Does anyone have any recommendations?

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• Rails find over multiple models

  - by kgb

  I think I'm missing something very obvious and its making my brain hurt. class User < ActiveRecord::Base has_one :profile class Profile < ActiveRecord::Base has_one :user belongs_to :team I have a partial that loops through the users and print some basic info, I'm using this partial in my team show page. I had originally written this to return users who's profiles were a member of a team. def show @team = Team.find_by_id(params[:id]) @profiles= Profile.find(:all, :conditions => ['team_id = ?', @team.id]) @users = User.find_by_id(@profiles.user_id) end But quickly realized @profiles was an array, and it looks messy as hell. Stuck as to what my find should look like to select all User who have a profile that is a member of a team. The partial that is working elsewhere for displaying users looks like this <% for user in @users%> <table> <tr> <td> <%= image_tag user.profile.picture.url %> </td> <td> <a href="/users/<%= user.id %>"><%= user.login %></a> </td> <td> <%= user.profile.first_name %> <%= user.profile.second_name %> </td> <td> <%= user.profile.status %> </td> </tr> </table> <% end %> Development log output with updated show and relationships Processing TeamsController#show (for 127.0.0.1 at 2010-03-30 22:06:31) [GET] Parameters: {"id"=>"1"} User Load (1.3ms) SELECT * FROM "users" WHERE ("users"."id" = 3) LIMIT 1 Team Load (1.0ms) SELECT * FROM "teams" WHERE ("teams"."id" = 1) Rendering template within layouts/main Rendering teams/show Completed in 75ms (View: 11, DB: 2) | 200 OK [http://localhost/teams/1]

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• Translating itunes affiliate rss via xslt

  - by jd

  I can't get this working for the life of me. Here is a snippet of the xml I get from an RSS feed from itunes affiliate. I want top print the values within tags but I cannot for some reason: <?xml version="1.0" encoding="utf-8"?> <feed xmlns:im="http://itunes.apple.com/rss" xmlns="http://www.w3.org/2005/Atom" xml:lang="en"> <id>http://ax.itunes.apple.com/WebObjects/MZStoreServices.woa/ws/RSS/toppaidapplications/sf=143441/limit=100/genre=6014/xml</id><title>iTunes Store: Top Paid Applications</title><updated>2010-03-24T15:36:42-07:00</updated><link rel="alternate" type="text/html" href="http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewTop?id=25180&amp;popId=30"/><link rel="self" href="http://ax.itunes.apple.com/WebObjects/MZStoreServices.woa/ws/RSS/toppaidapplications/sf=143441/limit=100/genre=6014/xml"/><icon>http://phobos.apple.com/favicon.ico</icon><author><name>iTunes Store</name><uri>http://www.apple.com/itunes/</uri></author><rights>Copyright 2008 Apple Inc.</rights> <entry> <updated>date</updated> <id>someID</id> <title>a</title> <im:name>b</im:name> </entry> <entry> <updated>date2/updated> <id>someID2</id> <title>a2</title> <im:name>b2</im:name> </entry> </feed> If I try <xsl:apply-templates match="entry"/> it spits out the entire contents of file. If I use <xsl:call-template name="entry"> it will show only one entry and I have to use <xsl:value-of select="//*[local-name(.)='name']"/> to get name but that's a hack. I've used xslt before for xml without namespaces and xml that has proper parent child relationships but not like this RSS feed. Notice entry is not wrapped in entries or anything. Any help is appreciated. I want to use xslt because I want to alter the itunes link to go through my affiliate account - so something automated wouldn't work for me.

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• Having trouble getting MEF imports to be resolved

  - by Dave

  This is sort of a continuation of one of my earlier posts, which involves the resolving of modules in my WPF application. This question is specifically related to the effect of interdependencies of modules and the method of constructing those modules (i.e. via MEF or through new) on MEF's ability to resolve relationships. First of all, here is a simple UML diagram of my test application: I have tried two approaches: left approach: the App implements IError right approach: the App has a member that implements IError Left approach My code behind looked like this (just the MEF-related stuff): // app.cs [Export(typeof(IError))] public partial class Window1 : Window, IError { [Import] public CandyCo.Shared.LibraryInterfaces.IPlugin Plugin { get; set; } [Export] public CandyCo.Shared.LibraryInterfaces.ICandySettings Settings { get; set; } private ICandySettings Settings; public Window1() { // I create the preferences here with new, instead of using MEF. I wonder // if that's my whole problem? If I use MEF, and want to have parameters // going to the constructor, then do I have to [Export] a POCO (i.e. string)? Settings = new CandySettings( "Settings", @"c:\settings.xml"); var catalog = new DirectoryCatalog( "."); var container = new CompositionContainer( catalog); try { container.ComposeParts( this); } catch( CompositionException ex) { foreach( CompositionError e in ex.Errors) { string description = e.Description; string details = e.Exception.Message; } throw; } } } // plugin.cs [Export(typeof(IPlugin))] public class Plugin : IPlugin { [Import] public CandyCo.Shared.LibraryInterfaces.ICandySettings CandySettings { get; set; } [Import] public CandyCo.Shared.LibraryInterfaces.IError ErrorInterface { get; set; } [ImportingConstructor] public Plugin( ICandySettings candy_settings, IError error_interface) { CandySettings = candy_settings; ErrorInterface = error_interface; } } // candysettings.cs [Export(typeof(ICandySettings))] public class CandySettings : ICandySettings { ... } Right-side approach Basically the same as the left-side approach, except that I created a class that inherits from IError in the same assembly as Window1. I then used an [Import] to try to get MEF to resolve that for me. Can anyone explain how the two ways I have approached MEF here are flawed? I have been in the dark for so long that instead of reading about MEF and trying different suggestions, I've added MEF to my solution and am stepping into the code. The part where it looks like it fails is when it calls partManager.GetSavedImport(). For some reason, the importCache is null, which I don't understand. All the way up to this point, it's been looking at the part (Window1) and trying to resolve two imported interfaces -- IError and IPlugin. I would have expected it to enter code that looks at other assemblies in the same executable folder, and then check it for exports so that it knows how to resolve the imports...

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• Does this mySQL Stored Procedure Work?

  - by Laxmidi

  Hi, I got the following stored procedure from http://dev.mysql.com/doc/refman/5.1/en/functions-that-test-spatial-relationships-between-geometries.html Does this work? CREATE FUNCTION myWithin(p POINT, poly POLYGON) RETURNS INT(1) DETERMINISTIC BEGIN DECLARE n INT DEFAULT 0; DECLARE pX DECIMAL(9,6); DECLARE pY DECIMAL(9,6); DECLARE ls LINESTRING; DECLARE poly1 POINT; DECLARE poly1X DECIMAL(9,6); DECLARE poly1Y DECIMAL(9,6); DECLARE poly2 POINT; DECLARE poly2X DECIMAL(9,6); DECLARE poly2Y DECIMAL(9,6); DECLARE i INT DEFAULT 0; DECLARE result INT(1) DEFAULT 0; SET pX = X(p); SET pY = Y(p); SET ls = ExteriorRing(poly); SET poly2 = EndPoint(ls); SET poly2X = X(poly2); SET poly2Y = Y(poly2); SET n = NumPoints(ls); WHILE i<n DO SET poly1 = PointN(ls, (i+1)); SET poly1X = X(poly1); SET poly1Y = Y(poly1); IF ( ( ( ( poly1X <= pX ) && ( pX < poly2X ) ) || ( ( poly2X <= pX ) && ( pX < poly1X ) ) ) && ( pY > ( poly2Y - poly1Y ) * ( pX - poly1X ) / ( poly2X - poly1X ) + poly1Y ) ) THEN SET result = !result; END IF; SET poly2X = poly1X; SET poly2Y = poly1Y; SET i = i + 1; END WHILE; RETURN result; End; Usage: SET @point = PointFromText('POINT(5 5)') ; SET @polygon = PolyFromText('POLYGON((0 0,10 0,10 10,0 10))') ; SELECT myWithin(@point, @polygon) AS result ; I'm using phpMyAdmin and it blows up when using stored procedures. If this one works, then I'll try to figure out how to call it in php instead. Thanks, Laxmidi

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• Simple database design and LINQ

  - by Anders Svensson

  I have very little experience designing databases, and now I want to create a very simple database that does the same thing I have previously had in xml. Here's the xml: <services> <service type="writing"> <small>125</small> <medium>100</medium> <large>60</large> <xlarge>30</xlarge> </service> <service type="analysis"> <small>56</small> <medium>104</medium> <large>200</large> <xlarge>250</xlarge> </service> </services> Now, I wanted to create the same thing in a SQL database, and started doing this ( hope this formats ok, but you'll get the gist, four columns and two rows): > ServiceType Small Medium Large > > Writing 125 100 60 > > Analysis 56 104 200 This didn't work too well, since I then wanted to use LINQ to select, say, the Large value for Writing (60). But I couldn't use LINQ for this (as far as I know) and use a variable for the size (see parameters in the method below). I could only do that if I had a column like "Size" where Small, Medium, and Large would be the values. But that doesn't feel right either, because then I would get several rows with ServiceType = Writing (3 in this case, one for each size), and the same for Analysis. And if I were to add more servicetypes I would have to do the same. Simply repetitive... Is there any smart way to do this using relationships or something? Using the second design above (although not good), I could use the following LINQ to select a value with parameters sent to the method: protected int GetHourRateDB(string serviceType, Size size) { CalculatorLinqDataContext context = new CalculatorLinqDataContext(); var data = (from calculatorData in context.CalculatorDatas where calculatorData.Service == serviceType && calculatorData.Size == size.ToString() select calculatorData).Single(); return data.Hours; } But if there is another better design, could you please also describe how to do the same selection using LINQ with that design? Please keep in mind that I am a rookie at database design, so please be as explicit and pedagogical as possible :-) Thanks! Anders

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• Complex relationship between tables in NHibernate

  - by Ilya Kogan

  Hi all, I'm writing a Fluent NHibernate mapping for a legacy Oracle database. The challenge is that the tables have composite primary keys. If I were at total freedom, I would redesign the relationships and auto-generate primary keys, but other applications must write to the same database and read from it, so I cannot do it. These are the two tables I'll focus on: Example data Trips table: 1, 10:00, 11:00 ... 1, 12:00, 15:00 ... 1, 16:00, 19:00 ... 2, 12:00, 13:00 ... 3, 9:00, 18:00 ... Faults table: 1, 13:00 ... 1, 23:00 ... 2, 12:30 ... In this case, vehicle 1 made three trips and has two faults. The first fault happened during the second trip, and the second fault happened while the vehicle was resting. Vehicle 2 had one trip, during which a fault happened. Constraints Trips of the same vehicle never overlap. So the tables have an optional one-to-many relationship, because every fault either happens during a trip or it doesn't. If I wanted to join them in SQL, I would write: select ... from Faults left outer join Trips on Faults.VehicleId = Trips.VehicleId and Faults.FaultTime between Trips.TripStartTime and Trips.TripEndTime and then I'd get a dataset where every fault appears exactly once (one-to-many as I said). Note that there is no Vehicles table, and I don't need one. But I did create a view that contains all VehicleIds from both tables, so I can use it as a junction table. What am I actually looking for? The tables are huge because they cover years of data, and every time I only need to fetch a range of a few hours. So I need a mapping and a criteria that will run something like the following SQL underneath: select ... from Faults left outer join Trips on Faults.VehicleId = Trips.VehicleId and Faults.FaultTime between Trips.TripStartTime and Trips.TripEndTime where Faults.FaultTime between :p0 and :p1 Do you have any ideas how to achieve it? Note 1: Currently the application shouldn't write to the database, so persistence is not a must, although if the mapping supports persistence, it may help at some point in the future. Note 2: I know it's a tough one, so if you give me a great answer, you will be properly rewarded :) Thank you for reading this long question, and now I only hope for the best :)

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• Complex Entity Framework linked-graphs issue: how to limit change set / break the graph?

  - by Hightechrider

  I have an EDMX containing Sentences, and Words, say and a Sentence contains three Words, say. Appropriate FK relationships exist between the tables. I create some words: Word word1 = new Word(); Word word2 = ... I build a Sentence: Sentence x = new Sentence (word1, word2, word3); I build another Sentence: Sentence y = new Sentence (word1, word4, word5); I try to save x to the database, but EF builds a change set that includes everything, including y, word4 and word5 that aren't ready to save to the database. When SaveChanges() happens it throws an exception: Unable to determine the principal end of the ... relationship. Multiple added entities may have the same primary key. I think it does this because Word has an EntityCollection<Sentence> on it from the FK relationship between the two tables, and thus Sentence y is inextricably linked to Sentence x through word1. So I remove the Navigation Property Sentences from Word and try again. It still tries to put the entire graph into the change set. What suggestions do the Entity Framework experts have for ways to break this connection. Essentially what I want is a one-way mapping from Sentence to Word; I don't want an EntityCollection<Sentence> on Word and I don't want the object graph to get intertwined like this. Code sample: This puts two sentences into the database because Verb1 links them and EF explores the entire graph of existing objects and added objects when you do Add/SaveChanges. Word subject1 = new Word(){ Text = "Subject1"}; Word subject2 = new Word(){ Text = "Subject2"}; Word verb1 = new Word(){ Text = "Verb11"}; Word object1 = new Word(){ Text = "Object1"}; Word object2 = new Word(){ Text = "Object2"}; Sentence s1 = new Sentence(){Subject = subject1, Verb=verb1, Object=object1}; Sentence s2 = new Sentence(){Subject=subject2, Verb=verb1, Object=object2}; context.AddToSentences(s1); context.SaveChanges(); foreach (var s in context.Sentences) { Console.WriteLine(s.Subject + " " + s.Verb + " " + s.Object); }

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• why is this rails association loading individually after an eager load?

  - by codeman73

  I'm trying to avoid the N+1 queries problem with eager loading, but it's not working. The associated models are still being loaded individually. Here are the relevant ActiveRecords and their relationships: class Player < ActiveRecord::Base has_one :tableau end Class Tableau < ActiveRecord::Base belongs_to :player has_many :tableau_cards has_many :deck_cards, :through => :tableau_cards end Class TableauCard < ActiveRecord::Base belongs_to :tableau belongs_to :deck_card, :include => :card end class DeckCard < ActiveRecord::Base belongs_to :card has_many :tableaus, :through => :tableau_cards end class Card < ActiveRecord::Base has_many :deck_cards end and the query I'm using is inside this method of Player: def tableau_contains(card_id) self.tableau.tableau_cards = TableauCard.find :all, :include => [ {:deck_card => (:card)}], :conditions => ['tableau_cards.tableau_id = ?', self.tableau.id] contains = false for tableau_card in self.tableau.tableau_cards # my logic here, looking at attributes of the Card model, with # tableau_card.deck_card.card; # individual loads of related Card models related to tableau_card are done here end return contains end Does it have to do with scope? This tableau_contains method is down a few method calls in a larger loop, where I originally tried doing the eager loading because there are several places where these same objects are looped through and examined. Then I eventually tried the code as it is above, with the load just before the loop, and I'm still seeing the individual SELECT queries for Card inside the tableau_cards loop in the log. I can see the eager-loading query with the IN clause just before the tableau_cards loop as well. EDIT: additional info below with the larger, outer loop Here's the larger loop. It is inside an observer on after_save def after_save(pa) @game = Game.find(turn.game_id, :include => :goals) @game.players = Player.find :all, :include => [ {:tableau => (:tableau_cards)}, :player_goals ], :conditions => ['players.game_id =?', @game.id] for player in @game.players player.tableau.tableau_cards = TableauCard.find :all, :include => [ {:deck_card => (:card)}], :conditions => ['tableau_cards.tableau_id = ?', player.tableau.id] if(player.tableau_contains(card)) ... end end end

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• SQL efficiency argument, add a column or solvable by query?

  - by theTurk

  I am a recent college graduate and a new hire for software development. Things have been a little slow lately so I was given a db task. My db skills are limited to pet projects with Rails and Django. So, I was a little surprised with my latest task. I have been asked by my manager to subclass Person with a 'Parent' table and add a reference to their custodian in the Person table. This is to facilitate going from Parent to Form when the custodian, not the Parent, is the FormContact. Here is a simplified, mock structure of a sql-db I am working with. I would have drawn the relationship tables if I had access to Visio. We have a table 'Person' and we have a table 'Form'. There is a table, 'FormContact', that relates a Person to a Form, not all Persons are related to a Form. There is a relationship table for Person to Person relationships (Employer, Parent, etc.) I've asked, "Why this couldn't be handled by a query?" Response, Inefficient. (Really!?!) So, I ask, "Why not have a reference to the Form? That would be more efficient since you wouldn't be querying the FormContacts table with the reference from child/custodian." Response, this would essentially make the Parent is a FormContact. (Fair enough.) I went ahead an wrote a query to get from non-FormContact Parent to Form, and tested on the production server. The response time was instantaneous. *SOME_VALUE* is the Parent's fk ID. SELECT FormID FROM FormContact WHERE FormContact.ContactID IN (SELECT SourceContactID FROM ContactRelationship WHERE (ContactRelationship.RelatedContactID = *SOME_VALUE*) AND (ContactRelationship.Relationship = 'Parent')); If I am right, "This is an unnecessary change." What should I do, defend my position or should I concede to the managers request? If I am wrong. What is my error? Is there a better solution than the manager's?

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• MS Access MSChart.Graph.8 not printing

  - by Tanj

  Software: Microsoft Access 2007 SP2 Database File Version: Access 2000 I have an access program that I inherited from a previous employee. It uses forms for reports and since I don't have much experience in access I have continued to do this. I have created a copy of the program for another project and modified it to suit. I am having trouble getting more then one chart to print. All the charts display in form view, they all have the same properties (excepting data, position, etc.) For some reason they are not printing. They don't even show up in the print preview. I am thinking it must be something with the graphs themselves as they sometimes lose all information. I have to open the graphs in edit mode and change the data source from column to row and back again so that it gets redrawn. (Refresh doesn't fix it) So right now I don't even have a clue as to where to look so ideas are welcome. Edit #1 It seems to be a problem with linking to an unbound form. Subform Field Linker: Can't build a link between unbound forms. The query for the main form is SELECT tTest.ixTest, tMotorTypes.ixMotorType, tMotorTypes.asMotorType, tMotorTypes.fDeprecated, tTestType.asTest, tTest.asSerialNum, tTest.asOrderNum, tTest.asFrameNum, tTest.asRotorNum, tTest.asOperator, tTest.iStation, tTest.dtTestDate, tTest.ixTestType FROM tMotorTypes INNER JOIN (tTestType INNER JOIN tTest ON tTestType.ixTestType=tTest.ixTestType) ON tMotorTypes.ixMotorType=tTest.ixMotorType; The query for the chart is: SELECT qGraphRSTTemperatures.Frequency, qGraphRSTTemperatures.[Drive End], qGraphRSTTemperatures.[Non Drive End], qGraphRSTTemperatures.[Air In], qGraphRSTTemperatures.Core FROM qGraphRSTTemperatures ORDER BY qGraphRSTTemperatures.ixTemperature; Query qGraphRSTTemperatures: SELECT tElectricalData.dblFrequency AS Frequency, tTemperatures.dblDrvEnd AS [Drive End], tTemperatures.dblNonDrvEnd AS [Non Drive End], tTemperatures.dblAirIn AS [Air In], tTemperatures.dblCore AS Core, tSubTest.ixTest, tTemperatures.ixTemperature FROM (tSubTest INNER JOIN tElectricalData ON tSubTest.ixSubTest = tElectricalData.ixSubTest) LEFT JOIN tTemperatures ON tElectricalData.ixElectrical = tTemperatures.ixElectrical WHERE (((tSubTest.ixSubTestType)=5)) ORDER BY tSubTest.ixTest, tTemperatures.ixTemperature; So how come, in the form view it shows the graph with the correct data when linked thus: Child field: ixTest Master field: ixTest but won't print the graph. The graph will print if I remove the links, but then I have all the data from chart query as it is not limited by ixTest. edit #2 It seems to be a data retrieval/rendering issue in printing. Is there anything in printing that changes the context of records with respect to parent/child relationships?

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• Django Multi-Table Inheritance VS Specifying Explicit OneToOne Relationship in Models

  - by chefsmart

  Hope all this makes sense :) I'll clarify via comments if necessary. Also, I am experimenting using bold text in this question, and will edit it out if I (or you) find it distracting. With that out of the way... Using django.contrib.auth gives us User and Group, among other useful things that I can't do without (like basic messaging). In my app I have several different types of users. A user can be of only one type. That would easily be handled by groups, with a little extra care. However, these different users are related to each other in hierarchies / relationships. Let's take a look at these users: - Principals - "top level" users Administrators - each administrator reports to a Principal Coordinators - each coordinator reports to an Administrator Apart from these there are other user types that are not directly related, but may get related later on. For example, "Company" is another type of user, and can have various "Products", and products may be supervised by a "Coordinator". "Buyer" is another kind of user that may buy products. Now all these users have various other attributes, some of which are common to all types of users and some of which are distinct only to one user type. For example, all types of users have to have an address. On the other hand, only the Principal user belongs to a "BranchOffice". Another point, which was stated above, is that a User can only ever be of one type. The app also needs to keep track of who created and/or modified Principals, Administrators, Coordinators, Companies, Products etc. (So that's two more links to the User model.) In this scenario, is it a good idea to use Django's multi-table inheritance as follows: - from django.contrib.auth.models import User class Principal(User): # # # branchoffice = models.ForeignKey(BranchOffice) landline = models.CharField(blank=True, max_length=20) mobile = models.CharField(blank=True, max_length=20) created_by = models.ForeignKey(User, editable=False, blank=True, related_name="principalcreator") modified_by = models.ForeignKey(User, editable=False, blank=True, related_name="principalmodifier") # # # Or should I go about doing it like this: - class Principal(models.Model): # # # user = models.OneToOneField(User, blank=True) branchoffice = models.ForeignKey(BranchOffice) landline = models.CharField(blank=True, max_length=20) mobile = models.CharField(blank=True, max_length=20) created_by = models.ForeignKey(User, editable=False, blank=True, related_name="principalcreator") modified_by = models.ForeignKey(User, editable=False, blank=True, related_name="principalmodifier") # # # Please keep in mind that there are other user types that are related via foreign keys, for example: - class Administrator(models.Model): # # # principal = models.ForeignKey(Principal, help_text="The supervising principal for this Administrator") user = models.OneToOneField(User, blank=True) province = models.ForeignKey( Province) landline = models.CharField(blank=True, max_length=20) mobile = models.CharField(blank=True, max_length=20) created_by = models.ForeignKey(User, editable=False, blank=True, related_name="administratorcreator") modified_by = models.ForeignKey(User, editable=False, blank=True, related_name="administratormodifier") I am aware that Django does use a one-to-one relationship for multi-table inheritance behind the scenes. I am just not qualified enough to decide which is a more sound approach.

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• 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.

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• Zend Table Relationship Modeling with Composite Key

  - by emeraldjava

  I have a table with a composite primary key using four columns. mysql> describe leaguesummary; +------------------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +------------------------+------------------+------+-----+---------+----------------+ | leagueid | int(10) unsigned | NO | PRI | NULL | auto_increment | | leaguetype | enum('I','T') | NO | PRI | NULL | | | leagueparticipantid | int(10) unsigned | NO | PRI | NULL | | | leaguestandard | int(10) unsigned | NO | | NULL | | | leaguedivision | varchar(5) | NO | PRI | NULL | | | leagueposition | int(10) unsigned | NO | | NULL | | I have the league object modelled as so (all plain enough mappings) <?php class Model_DbTable_League extends Zend_Db_Table_Abstract { protected $_name = 'league'; protected $_primary = 'id'; protected $_dependentTables = array('Model_DbTable_LeagueSummary'); And I've started like this on the new model class. I've mapped a simple reference map which returns all rows linked to the league id. // http://files.zend.com/help/Zend-Framework/zend.db.table.relationships.html // http://naneau.nl/2007/04/21/a-zend-framework-tutorial-part-one/ class Model_DbTable_LeagueSummary extends Zend_Db_Table_Abstract { protected $_name = "leaguesummary"; protected $_primary = array('leagueid', 'leaguetype','leagueparticipantid','leaguedivision'); protected $_referenceMap = array( 'Summary' => array( 'columns' => array('leagueid'), 'refTableClass' => 'Model_DbTable_League', 'refColumns' => array('id') ), ..... ); } ?> The simple case works when called from my controller public function listAction() { // action body $leagueTable = new Model_DbTable_League(); $this->view->leagues = $leagueTable->getLeagues(); $league = $leagueTable->getLeague(6); // work $summary = $league->findDependentRowset('Model_DbTable_LeagueSummary','Summary'); Zend_Debug::dump($summary,"",true); I'm not sure how i can define extra _referenceMap keys which will take extra contraint ket values. I would like to be able to define a set called 'MenA' in which the type and division values are hardcoded, and the league id is taken from the initial rowset. 'MenA' =>array( 'columns' => array('leagueid','leaguetype','leaguedivision'), 'refTableClass' => 'Model_DbTable_League', 'refColumns' => array("id","I","A") ) Is this style of mapping possible ie hardcoding the values into the 'refColumns'. The second crazy idea i had was to pass the variable values in as part of the third param of the findDependentRowset() method. $menA = $league->findDependentRowset('Model_DbTable_LeagueSummary','MenA',array("I","A")); Any suggestions on how I might use the Zend DB Table Relationship mapping correctly to do this would be appreciated. I'm not interested in the plain, old and ugly $db-select(a,b,c)-where(..) style solution.

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• MVC pattern implementation. What is the n-relation between its components

  - by Srodriguez

  Dear all, I'm working in a C# project and we are , in order to get some unity across the different parts of our UI, trying to use the MVC pattern. The client is windows form based and I'm trying to create a simple MVC pattern implementation. It's been more challenging than expected, but I still have some questions regarding the MVC pattern. The problem comes mostly from the n-n relationships between its components: Here is what I've understood, but I'm not sure at all of it. Maybe someone can correct me? Model: can be shared among different Views. 1-n relationship between Model-View View: shows the state of the model. only one controller (can be shared among different views?). 1-1 relationship with the Model, 1-1 relationship with the controller Controller: handles the user actions on the view and updates the model. One controller can be shared among different views, a controller interacts only with one model? I'm not sure about the two last ones: Can a view have several controller? Or can a view share a controller with another view? Or is it only a 1:1 relationship? Can a controller handle several views? can it interact with several models? Also, I take advantage of this question to ask another MVC related question. I've suppressed all the synchronous calls between the different members of the MVC, making use of the events and delegates. One last call is still synchronous and is actually the most important one: The call between the view and the controller is still synchronous, as I need to know rather the controller has been able to handle the user's action or not. This is very bad as it means that I could block the UI thread (hence the client itself) while the controller is processing or doing some work. How can I avoid this? I can make use of the callback but then how do i know to which event the callback comes from? PS: I can't change the pattern at this stage, so please avoid answers of type "use MVP or MVVC, etc ;) Thanks!

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