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  • Model relationships in ASP.NET MVC

    - by Fabiano
    Hi I recently started evaluating ASP.NET MVC. While it is really easy and quick to create Controllers and Views for Models with only primitive properties (like shown in the starter videos from the official page) I didn't find any good way to work with references to complex types. Let's say, I have these Models: public class Customer { public int Id { get; set; } public string Name { get; set; } public Address Address { get; set; } public IList<Order> Orders { get; set; } } public class Address { public int Id { get; set; } public string ..... ..... } public class Order { public int Id { get; set; } public Customer Customer { get; set; } public string OrderName { get; set; } ..... } Note that I don't have foreign keys in the models (like it's typical for LINQ to SQL, which is also used in the sample video) but an object reference. How can I handle such references in asp.net mvc? Does someone has some good tips or links to tutorials about this problem? maybe including autobinding with complex types.

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  • Hibernate bit array to entity mapping

    - by teabot
    I am trying to map a normalized Java model to a legacy database schema using Hibernate 3.5. One particular table encodes a foreign keys in a one-to-many relationship as a bit array column. Consider tables 'person' and 'clubs' that describes people's affiliations to clubs: person .----.------. club: .----.---------.---------------------------. | id | name | | id | name | members | binary(members) | |----+------| |----+---------|---------+-----------------| | 1 | Bob | | 10 | Cricket | 0 | 000 | | 2 | Joe | | 11 | Tennis | 5 | 101 | | 3 | Sue | | 12 | Cooking | 7 | 111 | '----'------' | 13 | Golf | 3 | 100 | '----'---------'---------'-----------------' So hopefully it is clear that person.id is used as the bit index in the bit array club.members. In this example the members column tells us that: no one is a member of Cricket, Bob/Sue - Tennis, Bob/Sue/Joe - Cooking and Sue - Golf. In my Java domain I'd like to declare this with entities like so: class Person { private int id; private String name; ... } class Club { private Set<Person> members; private int id; private String name; ... } I am assuming that I must use a UserType implementation but have been unable to find any examples where the items described by the user type are references to entities - not literal field values - or composites thereof. Additionally I am aware that I'll have to consider how the person entities are fetched when a club instance is loaded. Can anyone tell me how I can tame this legacy schema with Hibernate?

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  • user inheritance in django

    - by amateur
    Hi guys, I saw a couple of ways extending user information of users and decided to adopt the model inheritance method. for instance, I have : class Parent(User): contact_means = models.IntegerField() is_staff = False objects = userManager() Now it is done, I've downloaded django_registration to help me out with sending emails to new users. The thing is, instead of using registration forms to register new user, I want to to invoke the email sending/acitvation capability of django_registration. So my workflow is: 1. add new Parent object in admin page. 2. send email My problem is, the django-registration creates a new registration profile together with a new user in the user table. how do I tweak this such that I am able to add the user entry into the custom user table. I have tried to create a modelAdmin and alter the save_model method to launch the create_inactive_user from django_registration, however I do not how to save the user object generated from django_registration into my Parent table when I have using model inheritance and I do not have a Foreign key attribute in my parent model.

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  • How can I get a distinct list of elements in a hierarchical query?

    - by RenderIn
    I have a database table, with people identified by a name, a job and a city. I have a second table that contains a hierarchical representation of every job in the company in every city. Suppose I have 3 people in the people table: [name(PK),title,city] Jim, Salesman, Houston Jane, Associate Marketer, Chicago Bill, Cashier, New York And I have thousands of job type/location combinations in the job table, a sample of which follow. You can see the hierarchical relationship since parent_title is a foreign key to title: [title,city,pay,parent_title] Salesman, Houston, $50000, CEO Cashier, Houston, $25000 CEO, USA, $1000000 Associate Marketer, Chicago, $75000 Senior Marketer, Chicago, $125000 ..... The problem I'm having is that my Person table is a composite key, so I don't know how to structure the start with part of my query so that it starts with each of the three jobs in the cities I specified. I can execute three separate queries to get what I want, but this doesn't scale well. e.g.: select * from jobs start with city = (select city from people where name = 'Bill') and title = (select title from people where name = 'Bill') connect by prior parent_title = title UNION select * from jobs start with city = (select city from people where name = 'Jim') and title = (select title from people where name = 'Jim') connect by prior parent_title = title UNION select * from jobs start with city = (select city from people where name = 'Jane') and title = (select title from people where name = 'Jane') connect by prior parent_title = title How else can I get a distinct list (or I could wrap it with a distinct if not possible) of all the jobs which are above the three people I specified?

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  • Should this even be a has_many :through association?

    - by GoodGets
    A Post belongs_to a User, and a User has_many Posts. A Post also belongs_to a Topic, and a Topic has_many Posts. class User < ActiveRecord::Base has_many :posts end class Topic < ActiveRecord::Base has_many :posts end class Post < ActiveRecord::Base belongs_to :user belongs_to :topic end Well, that's pretty simple and very easy to set up, but when I display a Topic, I not only want all of the Posts for that Topic, but also the user_name and the user_photo of the User that made that Post. However, those attributes are stored in the User model and not tied to the Topic. So how would I go about setting that up? Maybe it can already be called since the Post model has two foreign keys, one for the User and one for the Topic? Or, maybe this is some sort of "one-way" has_many through assiociation. Like the Post would be the join model, and a Topic would has_many :users, :through = :posts. But the reverse of this is not true. Like a User does NOT has_many :topics. So would this even need to be has_many :though association? I guess I'm just a little confused on what the controller would look like to call both the Post and the User of that Post for a give Topic. Edit: Seriously, thank you to all that weighed in. I chose tal's answer because I used his code for my controller; however, I could have just as easily chosen either j.'s or tim's instead. Thank you both as well. This was so damn simple to implement, and I think today marks the day that I'm beginning to fall in love with rails.

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  • Django: How can I delete a formset entry if one of it's data is blank?

    - by mkret
    Hi, I have the following scenario: I have a form with data that does not need translation and a formset with a textfield that should be translated into an undefined amount of languages. Both parts are bound to a model. Each translated text is kept in a model with a foreign key that binds it to the untranslatable data. Something like: class Person(models.Model): name = models.CharField(max_length=60) birth_date = models.DateField() class PersonBio(models.Model): person = models.ForeignKey(Person) locale = models.CharField(max_length=10) bio = models.TextField() Each form in the formset has 2 fields: A textfield (with the translated text) A locale field (with the language into which the text was translated) I've got it working with no problems until I tryed to change it's normal behaviour. I wanted to eliminate the need for the DELETE field by deleting an instance of the translated text if the textfield was left blank. I've googled quite a lot now and read the whole documentation for forms, formsets and model validation but had no luck. To be honest, I couldn't even think of a solution. Where should I implement this? On a Form clean() method? On the view? Somewhere in the Fieldset? Fieldset's save() method, maybe? I'll keep trying to find a way to do that, but any help/tip/clue is appreciated. Thanks in advance.

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  • SPPersistedObject and List<T>

    - by Sam
    Hi I want sharepoint to "persist" a List of object I wrote a class SPAlert wich inherit from SPPersistedObject : public class SMSAlert: SPPersistedObject { [Persisted] private DateTime _scheduledTime; [Persisted] private Guid _listId; [Persisted] private Guid _siteID; } Then I wrote a class wich inherit from SPJobDefinition an add a List of my previous object: public sealed class MyCustomJob: SPJobDefinition { [Persisted] private List<SMSAlert> _SMSAlerts; } The problem is : when I call the Update method of y MyCustomJob: myCustomJob.Update(); It throw an exception : message : An object in the SharePoint administrative framework, depends on other objects which do not exist. Ensure that all of the objects dependencies are created and retry this operation. stack at Microsoft.SharePoint.Administration.SPConfigurationDatabase.StoreObject(SPPersistedObject obj, Boolean storeClassIfNecessary, Boolean ensure) at Microsoft.SharePoint.Administration.SPConfigurationDatabase.PutObject(SPPersistedObject obj, Boolean ensure) at Microsoft.SharePoint.Administration.SPPersistedObject.Update() at Microsoft.SharePoint.Administration.SPJobDefinition.Update() at Sigi.Common.AlertBySMS.SmsAlertHandler.ScheduleJob(SPWeb web, SPAlertHandlerParams ahp) inner exception An object in the SharePoint administrative framework depends on other objects which do not exist. The INSERT statement conflicted with the FOREIGN KEY constraint "FK_Dependencies1_Objects". The conflict occurred in database "SharePoint_Config, table "dbo.Objects", column 'Id'. The statement has been terminated. Can anyone help me with that??

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  • Flex special characters not embedding

    - by Hanpan
    Hi, I am using the following code to embed Arial into my application: [Embed(source='../assets/fonts/Arial.ttf',fontFamily='CustomFont',fontWeight='regular', unicodeRange='U+0020-U+0040,U+0041-U+005A,U+005B-U+0060,U+0061-U+007A,U+007B-U+007E,U+0080-U+00FF,U+0100-U+017F,U+0400-U+04FF,U+0370-U+03FF,U+1E00-U+1EFF,U+2022,U+2219,U+20AC-U+21AC', mimeType='application/x-font-truetype' )] public static var MY_FONT:Class; [Embed(source='../assets/fonts/Arial Bold.ttf',fontFamily='CustomFont',fontWeight='bold', unicodeRange='U+0020-U+0040,U+0041-U+005A,U+005B-U+0060,U+0061-U+007A,U+007B-U+007E,U+0080-U+00FF,U+0100-U+017F,U+0400-U+04FF,U+0370-U+03FF,U+1E00-U+1EFF,U+2022,U+2219,U+20AC-U+21AC', mimeType='application/x-font-truetype' )] public static var MY_FONT_BOLD:Class; [Embed(source='../assets/fonts/Arial Italic.ttf',fontFamily='CustomFont',fontWeight='regular',fontStyle="italic", unicodeRange='U+0020-U+0040,U+0041-U+005A,U+005B-U+0060,U+0061-U+007A,U+007B-U+007E,U+0080-U+00FF,U+0100-U+017F,U+0400-U+04FF,U+0370-U+03FF,U+1E00-U+1EFF,U+2022,U+2219,U+20AC-U+21AC', mimeType='application/x-font-truetype' )] public static var MY_FONT_ITALIC:Class; [Embed(source='../assets/fonts/Arial Bold Italic.ttf',fontFamily='CustomFont',fontWeight='bold',fontStyle="italic", unicodeRange='U+0020-U+0040,U+0041-U+005A,U+005B-U+0060,U+0061-U+007A,U+007B-U+007E,U+0080-U+00FF,U+0100-U+017F,U+0400-U+04FF,U+0370-U+03FF,U+1E00-U+1EFF,U+2022,U+2219,U+20AC-U+21AC', mimeType='application/x-font-truetype' )] public static var MY_FONT_ITALIC_BOLD:Class; [Embed(source='../assets/fonts/Arial Unicode.ttf',fontFamily='CustomFont',fontWeight='regular', unicodeRange='U+0020-U+0040,U+0041-U+005A,U+005B-U+0060,U+0061-U+007A,U+007B-U+007E,U+0080-U+00FF,U+0100-U+017F,U+0400-U+04FF,U+0370-U+03FF,U+1E00-U+1EFF,U+2022,U+2219,U+20AC-U+21AC', mimeType='application/x-font-truetype' )] public static var MY_FONT_UNICODE:Class; It's working fine for foreign characters, but no special characters (copyright, trademark, euro sign etc) are working. Can anyone help? I've checked my unicode ranges, they should work fine!

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  • The type of field isn't supported by declared persistence strategy "OneToMany"

    - by Robert
    We are new to JPA and trying to setup a very simple one to many relationship where a pojo called Message can have a list of integer group id's defined by a join table called GROUP_ASSOC. Here is the DDL: CREATE TABLE "APP"."MESSAGE" ( "MESSAGE_ID" INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1) ); ALTER TABLE "APP"."MESSAGE" ADD CONSTRAINT "MESSAGE_PK" PRIMARY KEY ("MESSAGE_ID"); CREATE TABLE "APP"."GROUP_ASSOC" ( "GROUP_ID" INTEGER NOT NULL, "MESSAGE_ID" INTEGER NOT NULL ); ALTER TABLE "APP"."GROUP_ASSOC" ADD CONSTRAINT "GROUP_ASSOC_PK" PRIMARY KEY ("MESSAGE_ID", "GROUP_ID"); ALTER TABLE "APP"."GROUP_ASSOC" ADD CONSTRAINT "GROUP_ASSOC_FK" FOREIGN KEY ("MESSAGE_ID") REFERENCES "APP"."MESSAGE" ("MESSAGE_ID"); Here is the pojo: @Entity @Table(name = "MESSAGE") public class Message { @Id @Column(name = "MESSAGE_ID") @GeneratedValue(strategy = GenerationType.IDENTITY) private int messageId; @OneToMany(fetch=FetchType.LAZY, cascade=CascadeType.PERSIST) private List groupIds; public int getMessageId() { return messageId; } public void setMessageId(int messageId) { this.messageId = messageId; } public List getGroupIds() { return groupIds; } public void setGroupIds(List groupIds) { this.groupIds = groupIds; } } When we try to execute the following test code we get <openjpa-1.2.3-SNAPSHOT-r422266:907835 fatal user error> org.apache.openjpa.util.MetaDataException: The type of field "pojo.Message.groupIds" isn't supported by declared persistence strategy "OneToMany". Please choose a different strategy. Message msg = new Message(); List groups = new ArrayList(); groups.add(101); groups.add(102); EntityManager em = Persistence.createEntityManagerFactory("TestDBWeb").createEntityManager(); em.getTransaction().begin(); em.persist(msg); em.getTransaction().commit(); Help!

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  • Multi-table Update(MySQL)

    - by smokinguns
    Hey all, I have a question regarding multi-table update(MySQL). Consider table t1 and t2. The PKEY for t1 is 'tid' which is a foreign Key in t2. There is a field "qtyt2" in t2 which depends on a field called "qtyt1" in table t1. Consider the foll SQL statement: UPDATE t2,t1 SET t2.qtyt2=IF(( t2.qtyt2- t1.qtyt1 )<0,0,( t2.qtyt2- t1.qtyt1 ) ), t1.qtyt1 ="Some value.." where t2.tid="some value.." AND t2.tid=t1.tid In this example qtyt2 depends on qtyt1 for update and the latter itself is updated.Now the result should return 2 if two rows are updated. Is there a guarantee that the fields will be updated in the order in which they appear in the statement( first qtyt2 will be set and then qtyt1).Is it possible that qtyt1 will be set first and then qtyt2? Is the order of tables in the statement important (UPDATE t2, t1 or UPDATE t1,t2)? I found that if I wrote "UPDATE t1,t2" then only t1 would get updated, but on changing the statement to "UPDATE t2,t1" everything worked correctly.

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  • Asynchronous callback - gwt

    - by sprasad12
    Hi, I am using gwt and postgres for my project. On the front end i have few widgets whose data i am trying to save on to tables at the back-end when i click on "save project" button(this also takes the name for the created project). In the asynchronous callback part i am setting more than one table. But it is not sending the data properly. I am getting the following error: org.postgresql.util.PSQLException: ERROR: insert or update on table "entitytype" violates foreign key constraint "entitytype_pname_fkey" Detail: Key (pname)=(Project Name) is not present in table "project". But when i do the select statement on project table i can see that the project name is present. Here is how the callback part looks like: oksave.addClickHandler(new ClickHandler(){ @Override public void onClick(ClickEvent event) { if(erasync == null) erasync = GWT.create(EntityRelationService.class); AsyncCallback<Void> callback = new AsyncCallback<Void>(){ @Override public void onFailure(Throwable caught) { } @Override public void onSuccess(Void result){ } }; erasync.setProjects(projectname, callback); for(int i = 0; i < boundaryPanel.getWidgetCount(); i++){ top = new Integer(boundaryPanel.getWidget(i).getAbsoluteTop()).toString(); left = new Integer(boundaryPanel.getWidget(i).getAbsoluteLeft()).toString(); if(widgetTitle.startsWith("ATTR")){ type = "regular"; erasync.setEntityAttribute(name1, name, type, top, left, projectname, callback); } else{ erasync.setEntityType(name, top, left, projectname, callback); } } } Question: Is it wrong to set more than one in the asynchronous callback where all the other tables are dependent on a particular table? when i say setProjects in the above code isn't it first completed and then moved on to the next one? Please any input will be greatly appreciated. Thank you.

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  • Movies recommendation engine conceptual database design

    - by Supyxy
    I am working at an movie recommendations engine and i'm facing a DB design issue. My actual database looks like this: MOVIES [ID,TITLE] KEYWORDS_TABLE [ID,KEY_ID] - where ID is Foreign Key for MOVIES.id and KEY_ID is a key for a text keywords table This is not the entire DB, but i showed here what's important for my problem. I have about 50,000 movies and about 1,3 milion keywords correlations, and basically my algorithm consists in extracting all the who have the same keywords with a given movie, then ordering them by the number of keywords correlations. For example i looked for a movie similar to 'Cast away' and it returned 'Six days and six nights' because it had the most keywords correlations (4 keywords): Island Airplane crash Stranded Pilot The algorithm is based on more factors, but this one is the most important and the most difficult for the approach. Basically what i do now is getting all the movies that have at least one keyword similar to the given movie and then ordering them by other factors which are not important for a moment. There wouldn't be any problem if there weren't so many records, a query lasts in many cases up to 10-20 seconds and some of them return even over 5000 movies. Someone already helped me on here (thanks Mark Byers) with optimizing the query but that's not enough because it takes too longer SELECT DISTINCT M.title FROM keywords_table K1 JOIN keywords_table K2 ON K2.key_id = K1.key_id JOIN movies M ON K2.id = M.id WHERE K1.id = 4 So i thought it would be better if i pre-made those lists with movies recommendations for each movie, but i'm not sure how to design the tables.. whatever is it a good idea or how would you take this approach?

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  • JPA @ManyToMany on only one side?

    - by Ethan Leroy
    I am trying to refresh the @ManyToMany relation but it gets cleared instead... My Project class looks like this: @Entity public class Project { ... @ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER) @JoinTable(name = "PROJECT_USER", joinColumns = @JoinColumn(name = "PROJECT_ID", referencedColumnName = "ID"), inverseJoinColumns = @JoinColumn(name = "USER_ID", referencedColumnName = "ID")) private Collection<User> users; ... } But I don't have - and I don't want - the collection of Projects in the User entity. When I look at the generated database tables, they look good. They contain all columns and constraints (primary/foreign keys). But when I persist a Project that has a list of Users (and the users are still in the database), the mapping table doesn't get updated gets updated but when I refresh the project afterwards, the list of Users is cleared. For better understanding: Project project = ...; // new project with users that are available in the db System.out.println(project getUsers().size()); // prints 5 em.persist(project); System.out.println(project getUsers().size()); // prints 5 em.refresh(project); System.out.println(project getUsers().size()); // prints 0 So, how can I refresh the relation between User and Project?

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  • SSIS: "Failure inserting into the read-only column <ColumnName>"

    - by Cory
    I have an Excel source going into an OLE DB destination. I'm inserting data into a view that has an INSTEAD OF trigger that handles all inserts. When I try to execute the package I receive this error: "Failure inserting into the read-only column ColumnName" What can I do to let SSIS know that this view is safe to insert into because there is an INSTEAD OF trigger that will handle the insert? EDIT (Additional info): Some more additional info. I have a flat file that is being inserted into a normalized database. My initial problem was how do I take a flat file and insert that data into multiple tables while keeping track of all the primary/foreign key relationships. My solution was to create a VIEW that mimicked the structure of the flat file and then create an INSTEAD OF trigger on that view. In my INSTEAD OF trigger I would handle the logic of maintaining all the relationships between tables My view looks something like this. CREATE VIEW ImportView AS SELECT CONVERT(varchar(100, NULL) AS CustomerName, CONVERT(varchar(100), NULL) AS Address1, CONVERT(varchar(100), NULL) AS Address2, CONVERT(varchar(100), NULL) AS City, CONVERT(char(2), NULL) AS State, CONVERT(varchar(250), NULL) AS ItemOrdered, CONVERT(int, NULL) AS QuantityOrdered ... I will never need to select from this view, I only use it to insert data into it from this flat file I receive. I need someway to tell SQL Server that the fields aren't really read only because there is an INSTEAD OF trigger on this view.

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  • MySQL - NULL value check and Dynamic SQL inside stored procedure

    - by Mithun P
    DROP PROCEDURE IF EXISTS HaveSomeFun; CREATE PROCEDURE HaveSomeFun(user_id CHAR(50),house_id CHAR(50),room_id CHAR(50),fun_text TEXT,video_url CHAR(100)) BEGIN DECLARE query_full TEXT; SET @fields_part = 'INSERT INTO fun(FunKey,UserKey,FunBody,LastModified'; SET @values_part = CONCAT(') VALUES( NewBinKey(), KeyToBin(\"', user_id, '\"), \"', fun_text, '\", NOW() '); IF (house_id) THEN SET @fields_part = CONCAT(@fields_part, ', HouseKey'); SET @values_part = CONCAT(@values_part, ', KeyToBin(\'', house_id, '\')'); END IF; IF (room_id) THEN SET @fields_part = CONCAT(@fields_part, ', RoomKey'); SET @values_part = CONCAT(@values_part, ', KeyToBin(\'', room_id, '\')'); END IF; IF (video_url IS NOT NULL) THEN SET @fields_part = CONCAT(@fields_part, ', VideoURL'); SET @values_part = CONCAT(@values_part, ', "', video_url, '"'); END IF; SET query_full = CONCAT(@fields_part, @values_part, ' );'); SET @query_full = query_full; PREPARE STMT FROM @query_full; EXECUTE STMT; SELECT query_full; END; And CALL HaveSomeFun('29B455DE-A9BC-102D-9C16-00163EEDFCFC', '', 'F82C47A8-64DE-11DF-9D7E-0026B9481364', 'Jokes apart', ''); will construct the below string in the variable query_full INSERT INTO fun(FunKey,UserKey,FunBody,LastModified, VideoURL) VALUES( NewBinKey(), KeyToBin("29B455DE-A9BC-102D-9C16-00163EEDFCFC"), "Jokes apart", NOW() , "" ); But I need to get INSERT INTO fun(FunKey,UserKey,FunBody,LastModified, RoomKey, VideoURL) VALUES( NewBinKey(), KeyToBin("29B455DE-A9BC-102D-9C16-00163EEDFCFC"), "Jokes apart", NOW() , KeyToBin('F82C47A8-64DE-11DF-9D7E-0026B9481364'), "" ); Something is missing in the check IF (room_id) THEN. But I cannot impose IF (room_id IS NOT NULL) THEN since it will create KeyToBin('') and RoomKey is foreign key , KeyToBin('') will produce an invalid RoomKey. Any Idea?

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  • mySQL Efficiency Issue - How to find the right balance of normalization...?

    - by Foo
    I'm fairly new to working with relational databases, but have read a few books and know the basics of good design. I'm facing a design decision, and I'm not sure how to continue. Here's a very over simplified version of what I'm building: People can rate photos 1-5, and I need to display the average votes on the picture while keeping track of the individual votes. For example, 12 people voted 1, 7 people voted 2, etc. etc. The normalization freak of me initially designed the table structure like this: Table pictures id* | picture | userID | Table ratings id* | pictureID | userID | rating With all the foreign key constraints and everything set as they shoudl be. Every time someone rates a picture, I just insert a new record into ratings and be done with it. To find the average rating of a picture, I'd just run something like this: SELECT AVG(rating) FROM ratings WHERE pictureID = '5' GROUP by pictureID Having it setup this way lets me run my fancy statistics to. I can easily find who rated a certain picture a 3, and what not. Now I'm thinking if there's a crapload of ratings (which is very possible in what I'm really designing), finding the average will became very expensive and painful. Using a non-normalized version would seem to be more efficient. e.g.: Table picture id | picture | userID | ratingOne | ratingTwo | ratingThree | ratingFour | ratingFive To calculate the average, I'd just have to select a single row. It seems so much more efficient, but so much more uglier. Can someone point me in the right direction of what to do? My initial research shows that I have to "find the right balance", but how do I go about finding that balance? Any articles or additional reading information would be appreciated as well. Thanks.

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  • inverse relation to multiple inheriting classes in django

    - by Ofri Raviv
    Here are my schematic models: class Law(models.Model): ... class Bill(models.Model): ... # data for a proposed law, or change of an existing law class PrivateBill(Bill): ... # data for a Bill that was initiated by a parliament member class GovernmentBill(Bill): ... # data for a Bill that was initiated by the government It is possible and likely that in the future I (or maybe someone else) would want to add more Bill types. Every Bill should point to a Law (indicating what law this bill is going to change) and my question is: What is the best way to implement this? If I add the ForeignKey(Law) to Bill, I'll have a relation from every Bill to Law, but a Law would only have an inverse relation to Bills (bill_set), and not a different inverse relation to each type of bill. Of course I'll be able to filter each type of bill to get only the ones pointing to a specific Law, but this is something I think I'll need to use often, so I think having privatebill_set, governmentbill_set etc would make the code more readable. Another possible solution is to add the foreign key to each of the inheriting classes (this would give me a privatebill_set, governmentbill_set, futurebill_set), but that seems hairy because I would be relying on future programmers to remember to add that relation. How would you solve this?

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  • Sort and limit queryset by comment count and date using queryset.extra() (django)

    - by thornomad
    I am trying to sort/narrow a queryset of objects based on the number of comments each object has as well as by the timeframe during which the comments were posted. Am using a queryset.extra() method (using django_comments which utilizes generic foreign keys). I got the idea for using queryset.extra() (and the code) from here. This is a follow-up question to my initial question yesterday (which shows I am making some progress). Current Code: What I have so far works in that it will sort by the number of comments; however, I want to extend the functionality and also be able to pass a time frame argument (eg, 7 days) and return an ordered list of the most commented posts in that time frame. Here is what my view looks like with the basic functionality in tact: import datetime from django.contrib.comments.models import Comment from django.contrib.contenttypes.models import ContentType from django.db.models import Count, Sum from django.views.generic.list_detail import object_list def custom_object_list(request, queryset, *args, **kwargs): '''Extending the list_detail.object_list to allow some sorting. Example: http://example.com/video?sort_by=comments&days=7 Would get a list of the videos sorted by most comments in the last seven days. ''' try: # this is where I started working on the date business ... days = int(request.GET.get('days', None)) period = datetime.datetime.utcnow() - datetime.timedelta(days=int(days)) except (ValueError, TypeError): days = None period = None sort_by = request.GET.get('sort_by', None) ctype = ContentType.objects.get_for_model(queryset.model) if sort_by == 'comments': queryset = queryset.extra(select={ 'count' : """ SELECT COUNT(*) AS comment_count FROM django_comments WHERE content_type_id=%s AND object_pk=%s.%s """ % ( ctype.pk, queryset.model._meta.db_table, queryset.model._meta.pk.name ), }, order_by=['-count']).order_by('-count', '-created') return object_list(request, queryset, *args, **kwargs) What I've Tried: I am not well versed in SQL but I did try just to add another WHERE criteria by hand to see if I could make some progress: SELECT COUNT(*) AS comment_count FROM django_comments WHERE content_type_id=%s AND object_pk=%s.%s AND submit_date='2010-05-01 12:00:00' But that didn't do anything except mess around with my sort order. Any ideas on how I can add this extra layer of functionality? Thanks for any help or insight.

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  • Python halts while iteratively processing my 1GB csv file

    - by Dan
    I have two files: metadata.csv: contains an ID, followed by vendor name, a filename, etc hashes.csv: contains an ID, followed by a hash The ID is essentially a foreign key of sorts, relating file metadata to its hash. I wrote this script to quickly extract out all hashes associated with a particular vendor. It craps out before it finishes processing hashes.csv stored_ids = [] # this file is about 1 MB entries = csv.reader(open(options.entries, "rb")) for row in entries: # row[2] is the vendor if row[2] == options.vendor: # row[0] is the ID stored_ids.append(row[0]) # this file is 1 GB hashes = open(options.hashes, "rb") # I iteratively read the file here, # just in case the csv module doesn't do this. for line in hashes: # not sure if stored_ids contains strings or ints here... # this probably isn't the problem though if line.split(",")[0] in stored_ids: # if its one of the IDs we're looking for, print the file and hash to STDOUT print "%s,%s" % (line.split(",")[2], line.split(",")[4]) hashes.close() This script gets about 2000 entries through hashes.csv before it halts. What am I doing wrong? I thought I was processing it line by line. ps. the csv files are the popular HashKeeper format and the files I am parsing are the NSRL hash sets. http://www.nsrl.nist.gov/Downloads.htm#converter UPDATE: working solution below. Thanks everyone who commented! entries = csv.reader(open(options.entries, "rb")) stored_ids = dict((row[0],1) for row in entries if row[2] == options.vendor) hashes = csv.reader(open(options.hashes, "rb")) matches = dict((row[2], row[4]) for row in hashes if row[0] in stored_ids) for k, v in matches.iteritems(): print "%s,%s" % (k, v)

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  • Storing User Information in Session with aspNetMembershipProvider

    - by Muhammad Adeel Zahid
    Hi Everyone, i m developing an application in .NET mvc2. i m using aspnetMembershipProvider for User registration and related activities. i need some custom information about user that i stored in a separate table (sysUser for example) and linked it to aspnetUser table through foreign key. after Login i need to fetch user's credentials from sysUser table and push it to the session. For this Account controller's Logon method seemed best to me and i pasted following code in my Logon ActionResult if (!ValidateLogOn(userName, password)) { return View(); } FormsAuth.SignIn(userName, rememberMe); ApplicationRepository _ApplicationRepository = new ApplicationRepository(); MembershipUser aspUser = Membership.GetUser(userName); SessionUser CurrentUser = _ApplicationRepository.GetUserCredentials(aspUser.ProviderUserKey.ToString()); //Session["CurrentUser"] = CurrentUser; if (!String.IsNullOrEmpty(returnUrl)) { return Redirect(returnUrl); } else { return RedirectToAction("Index", "Home"); } The code is working perfectly for me and put my desired information in the session but the thing is that if a user selects Remember me and on his next visit he won't have to Log in and i would not find my desired information in the Session. Can anyone guide me where should i put my code that stores the user information in the session. any Help is Highly appreciated Regards Adeel

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  • Using Linq2Sql to insert data into multiple tables using an auto incremented primary key

    - by Thomas
    I have a Customer table with a Primary key (int auto increment) and an Address table with a foreign key to the Customer table. I am trying to insert both rows into the database in one nice transaction. using (DatabaseDataContext db = new DatabaseDataContext()) { Customer newCustomer = new Customer() { Email = customer.Email }; Address b = new Address() { CustomerID = newCustomer.CustomerID, Address1 = billingAddress.Address1 }; db.Customers.InsertOnSubmit(newCustomer); db.Addresses.InsertOnSubmit(b); db.SubmitChanges(); } When I run this I was hoping that the Customer and Address table automatically had the correct keys in the database since the context knows this is an auto incremented key and will do two inserts with the right key in both tables. The only way I can get this to work would be to do SubmitChanges() on the Customer object first then create the address and do SubmitChanges() on that as well. This would create two roundtrips to the database and I would like to see if I can do this in one transaction. Is it possible? Thanks

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  • General many-to-many relationship problem ( Postgresql )

    - by David
    Hi, i have two tables: CREATE TABLE "public"."auctions" ( "id" VARCHAR(255) NOT NULL, "auction_value_key" VARCHAR(255) NOT NULL, "ctime" TIMESTAMP WITHOUT TIME ZONE NOT NULL, "mtime" TIMESTAMP WITHOUT TIME ZONE NOT NULL, CONSTRAINT "pk_XXXX2" PRIMARY KEY("id"), ); and CREATE TABLE "public"."auction_values" ( "id" NUMERIC DEFAULT nextval('default_seq'::regclass) NOT NULL, "fk_auction_value_key" VARCHAR(255) NOT NULL, "key" VARCHAR(255) NOT NULL, "value" TEXT, "ctime" TIMESTAMP WITHOUT TIME ZONE NOT NULL, "mtime" TIMESTAMP WITHOUT TIME ZONE NOT NULL, CONSTRAINT "pk_XXXX1" PRIMARY KEY("id"), ); if i want to create a many-to-many relationship on the auction_value_key like this: ALTER TABLE "public"."auction_values" ADD CONSTRAINT "auction_values_fk" FOREIGN KEY ("fk_auction_value_key") REFERENCES "public"."auctions"("auction_value_key") ON DELETE NO ACTION ON UPDATE NO ACTION NOT DEFERRABLE; i get this SQL error: ERROR: there is no unique constraint matching given keys for referenced table "auctions" Question: As you might see, i want "auction_values" to be be "reused" by different auctions without duplicating them for every auction... So i don't want a key relation on the "id" field in the auctions table... Am i thinking wrong here or what is the deal? ;) Thanks

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  • Canonical resource for forms-based design in ASP.NET MVC?

    - by Robert Harvey
    Is there a resource on the web that describes various form scenarios in ASP.NET MVC, and gives example solutions within a sensible, consistent design philosophy? Examples of such scenarios might be: One-to-many forms, like invoice data-entry forms. Foreign-table forms such as Add New User in a form that requires specifying a user Forms that require dynamic interaction, using Ajax or JSON. Popup forms Forms requiring multiple data records to be input, without postbacks. Note that there is considerable conceptual and technological overlap among these example scenarios. I am aware that there is a vast patchwork quilt of available technologies and examples out there that provide partial solutions and pieces of solutions, such as jQuery Ajax, CSS, and so forth. But I would like guidance in using these technologies in more effective and consistent ways. I am not considering web forms integration with an ASP.NET MVC application; I would still like my applications to be pure MVC. Nor am I, at the moment, considering a paid solution like Telerik. But I would like to know if someone has already done some of the work combining these technologies into a consistent, cohesive whole, that follows a sensible design philosophy. (an open source framework, perhaps?)

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  • SCD2 + Merge Statement + SQL Server

    - by Nev_Rahd
    I am trying work out with MERGE statment to Insert / Update Dimension Table of Type SCD2 My source is a Table var to Merge with Dimension table. My MERGE statement is throwing an error as: The target table 'DM.DATA_ERROR.ERROR_DIMENSION' of the INSERT statement cannot be on either side of a (primary key, foreign key) relationship when the FROM clause contains a nested INSERT, UPDATE, DELETE, or MERGE statement. Found reference constraint 'FK_ERROR_DIMENSION_to_AUDIT_CreatedBy'. My MERGE Statement: DECLARE @DATAERROROBJECT AS [ERROR_DIMENSION] INSERT INTO DM.DATA_ERROR.ERROR_DIMENSION SELECT ERROR_CODE, DATA_STREAM_ID, [ERROR_SEVERITY], DATA_QUALITY_RATING, ERROR_LONG_DESCRIPTION, ERROR_DESCRIPTION, VALIDATION_RULE, ERROR_TYPE, ERROR_CLASS, VALID_FROM, VALID_TO, CURR_FLAG, CREATED_BY_AUDIT_SK, UPDATED_BY_AUDIT_SK FROM (MERGE DM.DATA_ERROR.ERROR_DIMENSION ED USING @DATAERROROBJECT OBJ ON(ED.ERROR_CODE = OBJ.ERROR_CODE AND ED.DATA_STREAM_ID = OBJ.DATA_STREAM_ID) WHEN NOT MATCHED THEN INSERT VALUES( OBJ.ERROR_CODE ,OBJ.DATA_STREAM_ID ,OBJ.[ERROR_SEVERITY] ,OBJ.DATA_QUALITY_RATING ,OBJ.ERROR_LONG_DESCRIPTION ,OBJ.ERROR_DESCRIPTION ,OBJ.VALIDATION_RULE ,OBJ.ERROR_TYPE ,OBJ.ERROR_CLASS ,GETDATE() ,'9999-12-13' ,'Y' ,1 ,1 ) WHEN MATCHED AND ED.CURR_FLAG = 'Y' AND ( ED.[ERROR_SEVERITY] <> OBJ.[ERROR_SEVERITY] OR ED.[DATA_QUALITY_RATING] <> OBJ.[DATA_QUALITY_RATING] OR ED.[ERROR_LONG_DESCRIPTION] <> OBJ.[ERROR_LONG_DESCRIPTION] OR ED.[ERROR_DESCRIPTION] <> OBJ.[ERROR_DESCRIPTION] OR ED.[VALIDATION_RULE] <> OBJ.[VALIDATION_RULE] OR ED.[ERROR_TYPE] <> OBJ.[ERROR_TYPE] OR ED.[ERROR_CLASS] <> OBJ.[ERROR_CLASS] ) THEN UPDATE SET ED.CURR_FLAG = 'N', ED.VALID_TO = GETDATE() OUTPUT $ACTION ACTION_OUT, OBJ.ERROR_CODE ERROR_CODE, OBJ.DATA_STREAM_ID DATA_STREAM_ID, OBJ.[ERROR_SEVERITY] [ERROR_SEVERITY], OBJ.DATA_QUALITY_RATING DATA_QUALITY_RATING, OBJ.ERROR_LONG_DESCRIPTION ERROR_LONG_DESCRIPTION, OBJ.ERROR_DESCRIPTION ERROR_DESCRIPTION, OBJ.VALIDATION_RULE VALIDATION_RULE, OBJ.ERROR_TYPE ERROR_TYPE, OBJ.ERROR_CLASS ERROR_CLASS, GETDATE() VALID_FROM, '9999-12-31' VALID_TO, 'Y' CURR_FLAG, 555 CREATED_BY_AUDIT_SK, 555 UPDATED_BY_AUDIT_SK ) AS MERGE_OUT WHERE MERGE_OUT.ACTION_OUT = 'UPDATE'; What am I doing wrong ?

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  • DB2 Child Table Not Working - Create Table

    - by gamerzfuse
    I have a bit of a task before me. (DB2 Database) I need to create a table that will be a child table (is that what it is called in SQL?) I need it so that it has a foreign key constraint with my other table, so when the parent table is modified (record deleted) the child table also loses that record. Once I have the table, I also need to populate it with the data from the other table (if there is an easy way to UPDATE this). If you could point me in the right direction, this would help alot, as I do not even know what syntax to look for. Thanks in advance The table I have in place: create table titleauthors ( au_id char(11), title_id char(6), au_ord integer, royaltyshare decimal(5,2)); The table I am creating: create table titles ( title_id char(6), title varchar(80), type varchar(12), pub_id char(4), price decimal(9,2), advance decimal(9,2), ytd_sales integer, contract integer, notes varchar(200), pubdate date); I need the title_id to be matched with the title_id from the parent table AND use the ON DELETE CASCADE syntax to delete when that table is deleted from. My Attempt: CREATE TABLE BookTitles ( title_id char(6) NOT NULL CONSTRAINT BookTitles_title_id_pk REFERENCES titleauthors(title_id) ON DELETE CASCADE, title varchar(80) NOT NULL, type varchar(12), pub_id char(4), price decimal(9,2), advance decimal(9,2), ytd_sales integer, contract integer, notes varchar(200), pubdate date) ; Thanks in advance!

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