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  • Referencing not-yet-defined variables - Java

    - by user2537337
    Because I'm tired of solving math problems, I decided to try something more engaging with my very rusty (and even without the rust, very basic) Java skills. I landed on a super-simple people simulator, and thus far have been having a grand time working through the various steps of getting it to function. Currently, it generates an array of people-class objects and runs a for loop to cycle through a set of actions that alter the relationships between them, which I have stored in a 2d integer array. When it ends, I go look at how much they all hate each other. Fun stuff. Trouble has arisen, however, because I would like the program to clearly print what action is happening when it happens. I thought the best way to do this would be to add a string, description, to my "action" class (which stores variables for the actor, reactor, and the amount the relationship changes). This works to a degree, in that I can print a generic message ("A fight has occurred!") with no problem. However, ideally I would like it to be a little more specific ("Person A has thrown a rock at Person B's head!"). This latter goal is proving more difficult: attempting to construct an action with a description string that references actor and reactor gets me a big old error, "Cannot reference field before it is defined." Which makes perfect sense. I believe I'm not quite in programmer mode, because the only other way I can think to do this is an unwieldy switch statement that negates the need for each action to have its own nicely-packaged description. And there must be a neater way. I am not looking for examples of code, only a push in the direction of the right concept to handle this.

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  • Using IAM for user authentication

    - by mdavis6890
    I've read lots and lots of posts that touch on what I think should be a very common use case - but without finding exactly what I want, or a simple reason why it can't be done. I have some files on S3. I want to be able to grant certain users access to certain files, via a front end that I build. So far, I've made it work this way: I built the front end in Django, using it's built-in Users and Groups I have a model for Buckets, in which I mirror my S3 buckets. I have a m2m relationship from groups to buckets representing the S3 permissions. The user logs in and authenticates against Django's users. I grab from Django the list of buckets that the user is allowed to see I use boto to grab a list of links to files from those buckets and display to user. This works, but isn't ideal, and also just doesn't feel right. I've got to keep a mirror of the buckets, and I also have to maintain my own list of user/passwords and permissions, when AWS already has all that built in. What I really want is to simply create the users in IAM and use group permissions in IAM to control access to the S3 buckets. No duplication of data or function. My app would request a UN/PW from the user and use that to connect to IAM/S3 to pull the list of buckets and files, then display links to the user. Simple. How can I, or why can't I? Am I looking at this the wrong way? What's the "right" way to address this (I assume) very common use case?

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  • updating dataset using join and bindingsource?

    - by netadictos
    Hi, I have created a dataset and in the designer I have created the relations and foreign keys that exist in the database. Basically, I have a product that has a relationship to a table of prices. The keyfield they share is IdProduct in the Prices table. In the Fill/Get of the product I return the Price field. I also have a DataGrid that uses a BindingSource which uses this table. Everything displays correctly and when I double click on a row within the datagrid I then open up a tabbed form that contains a detailed view of the record selected. The user at this point is able to make changes to the record and they are properly propogated back to the BindingSource. The problem is that the TableAdapter does not contain the appopriate update, therefore I am not able to call the TableAdapter.Update method with the dataset as I would had I created a tableadapter not using a join. How am I best to handle this situation. At the same time I cannot get any modified row: dTiendasDs.ProductosDataTable modified = (dTiendasDs.ProductosDataTable) dTiendasDs.Productos.GetChanges(DataRowState.Modified); modified is always null Thanks,

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  • SQL n:m Inheritance join

    - by Nightmares
    I want to join a table which contains n:m relationship between groups. (Groups are defined in a separate table). This table only has entries listing a member_group_id and a parent_group_id. Given this structure: id(int) | member_group_id(int) | parent_group_id(int) The "base" query looks like this: select p1.group_id, p2.group_id, p1.member_group_id, p2.member_group_id from group_member_group as p1 join group_member_group as p2 on p2.member_group_id = p1.member_group_id The "base" query correctly shows all relationships (I checked by doing it manually.) The problem is when I try to apply a where clause to this query to filter for a specific group as "point of origin" (the first group for which I want all parent groups) it returns only the closest parents. For example like this: select p1.group_id, p2.group_id, p1.member_group_id, p2.member_group_id from group_member_group as p1 join group_member_group as p2 on p2.member_group_id = p1.member_group_id where p1.group_id = 1 Can anyone give a clue how I can fix this? Or a different approach to realize this. (I suppose I could always do this in my C++ source code on the server side but I would have to transfer a entire table which has a high growth potential to the application server.) UPDATE: select p1.group_id, p2.group_id, p1.member_group_id, p2.member_group_id from group_member_group as p1 join group_member_group as p2 on p2.group_id = p1.member_group_id Typing mistake confirmed. Now I don't get past first level of inheritance period. Thanks at denied for pointing that out.

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  • How to do HABTM management with auto completion in Rails?

    - by Andrei
    I am looking for a good solution for a probably typical problem of managing models with HABTM association in Rails. Let's assume that we have two models -- products and categories: Products has_many :categorizations has_many :categories, :through => :categorizations Categories has_many :categorizations has_many :products, :through => :categorizations Categorization belongs_to :product belongs_to :category Pat Shaughnessy is developing modified auto_complete plugin which can allow to manage one-to-many (and many-to-many) association: For someone that would be enough, but I don't really like so many text fields. I guess it is possible to combine the Ryan Bates' screencasts used by Pat in a slightly different way, namely, using one text field with autocomplete: Also it would be better to remove from the list of suggested tasks (one-to-many), or products|categories (many-to-many) those which have been already added. In the case of products-categories relationship, such auto completion would be used both in the form for product, and in the form for category. I hope that there is an existing plugin for that. I am not very experienced in Ruby, and don't really know how to implement such logic by myself. Any help is appreciated!

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  • MonoRail CheckboxList?

    - by Justin
    I'm trying to use a Checkboxlist in MonoRail to represent a many to many table relationship. There is a Special table, SpecialTag table, and then a SpecialTagging table which is the many to many mapping table between Special and SpecialTag. Here is an excerpt from the Special model class: [HasAndBelongsToMany(typeof(SpecialTag), Table = "SpecialTagging", ColumnKey = "SpecialId", ColumnRef = "SpecialTagId")] public IList<SpecialTag> Tags { get; set; } And then in my add/edit special view: $Form.LabelFor("special.Tags", "Tags")<br/> #set($items = $FormHelper.CreateCheckboxList("special.Tags", $specialTags)) #foreach($specialTag in $items) $items.Item("$specialTag.Id") $Form.LabelFor("$specialTag.Id", $specialTag.Name) #end The checkboxlist renders correctly, but if I select some and then click Save, it doesn't save the special/tag associations to the SpecialTagging table (the entity passed to the Save controller action has an empty Tags list.) One thing I noticed was that the name and value attributes on the checkboxes are funky: <label for="special_Tags">Tags</label><br> <input id="3" name="special.Tags[0]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="3">Buy 1 Get 1 Free</label> <input id="1" name="special.Tags[1]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="1">Free</label> <input id="2" name="special.Tags[2]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="2">Half Price</label> <input id="5" name="special.Tags[3]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="5">Live Music</label> <input id="4" name="special.Tags[4]" value="UCampus.Core.Models.SpecialTag" type="checkbox"> <label for="4">Outdoor Seating</label> Anyone have any ideas? Thanks! Justin

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  • Seeding many to many tables with Entity Framework

    - by Doozer1979
    I have a meeting entity and a users entity which have a many to many relationship. I'm using Autopoco to create seed data for the Users and meetings How do i seed the UserMeetings linking table that is created by EntityFramework with seed data? The linking table has two fields in it; User_Id, and Meeting_ID. I'm looping through the list of users that autopoco creates and attaching a random number of meetings Here's what i've got so far. foreach (var user in userList) { var rand = new Random(); var amountOfMeetingsToAdd = rand.Next(1, 300); for (var i = 0; i <= amountOfMeetingsToAdd; i++) { var randomMeeting = rand.Next(1, MeetingRecords); //Error occurs on This line user.Meetings.Add(_meetings[randomMeeting]); } } I got an 'Object reference not set to an instance of an object.' even though the meeting record that i'm trying to attach does exist. For info all this is happening prior to me saving the context to the DB.

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  • How to Connect to a web service (SSL enabled and proxy interface)

    - by blgnklc
    There is a web service running on tomcat on a server. It is built on Java Servlet. It is listening others to call itself on a SSL enabled http port. so its web service adreess looks like: https://172.29.12.12/axis/services/XYZClient?wsdl On the other hand I want to connect the web service above from a windows application which is built on .NET frame work. Finally, when I want to connect the web service from my computer; I get some specific erros; Firstly I get; Proxy authentication error; then I added some new line to my code; Dim cr As System.Net.NetworkCredential = New System.Net.NetworkCredential("xname", "xsurname", "xdomainname") Dim myProxy As New WebProxy("http://mar.xxxyyy.com", True) myProxy.Credentials = cr Secondly, after this modifications It says that bad request. I did not get over this error. Moreover I did try to connect the web server on the same computer. I copied my executable program to the computer where the web service runs. The error was like; The underlying connection was closed: Could not establish trust relationship for SSL/TLS secure channel PS: When I try to connect to web service by using Internet Explorer; I see firstly some warnings about accepting an unknown certificate and I click take me to web service an I get there clearly. I want to know what are the basic elements to connect a web service, could you please tell me the requirements that I have to use on my windows project. regards bk

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  • Class design when working with dataset

    - by MC
    If you have to retrieve data from a database and bring this dataset to the client, and then allow the user to manipulate the data in various ways before updating the database again, what is a good class design for this if the data tables will not have a 1:1 relationship with the class objects? Here are some I came up with: Just manipulate the DataSet itself on the client and then send it back to the database as is. This will work though obviously the code will be very dirty and not well-structured. Same as #1, but wrap the dataset code around classes. What I mean is that you may have a class that takes a dataset or a datatable in its constructor, and then provides public methods and properties to simplify the code. Inside these methods and properties it will be reading or manipulating the dataset. To update the database afterwards will be easy because you already have the updated dataset. Get rid of the dataset entirely on the client, convert to objects, then convert back to a dataset when needing to update the database. Is there any good resources where I can find information on this?

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  • Passing params in rails... Breakthrough in understanding params, aka, the "aha" moment

    - by Brian McDonough
    I have a simple has_many belongs_to relationship and I want to include the parent object for the view of the belongs_to model and I have had some success, but I want it to work better. class Submission < ActiveRecord::Base belongs_to :user belongs_to :contest end class Contest < ActiveRecord::Base belongs_to :user has_many :submissions, :dependent => :destroy end In the case that works, I pass contest_id to submissions by placing it in the url: <%= link_to 'Submit Contest Entry', new_submission_path(:contest_id => @contest.id), :class => 'btn btn-primary btn-large mleft10' %> So that, combined with a hidden_field: <%= f.hidden_field :contest_id %> And a find_contest method in the controller (called with a before_filter): def find_contest #the next line is giving the error (line 76) @contest = Contest.find(params[:submission][:contest_id]) end Makes it work for submissions/new, but how do I add a find to the controller that just works across more than that one page, like if I want to access in show and index. Right now, I get an error: Started GET "/submissions?contest_id=5" for 127.0.0.1 at 2012-12-01 16:01:45 -0800 Processing by SubmissionsController#index as HTML Parameters: {"contest_id"=>"5"} User Load (0.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = 2 ORDER BY users.created_at DESC LIMIT 1 Completed 500 Internal Server Error in 37ms NoMethodError (undefined method `[]' for nil:NilClass): app/controllers/submissions_controller.rb:76:in `find_contest' [edited] Adding show action for submissions: before_filter :find_contest, :except => [:index, :show, :edit, :update, :destroy] def find_contest @contest = Contest.find(params[:submission][:contest_id]) end def show contest_id = @submission.contest_id @submission = @commentable = Submission.find(params[:id]) @comments = @commentable.comments.order(:created_at).reverse respond_to do |format| format.html # show.html.erb format.json { render :json => @submission } end end

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  • Intermittent Issue Writing to Google Appengine Datastore

    - by user242153
    Hi, I have a functioning app and recently have had intermittent problems writing to the datastore. I did not make any relevant code changes, however in the last few days my attempts to write to the datastore sometimes work and sometimes don't. I am trying to save an object that is in a many to one relationship with an existing persisted parent. So, the logic works like this: 1) Parent pulled from the datastore 2) Child created / instantiated using constructor 3) Parent.addSingleChild(child); // the "addSingleChild" method just adds the object argument to the collection of children 4) child.setParent(Parent); // sets the Parent object to the parent field I am using transactions as explained in the documentation ending with "finally {if (tx.isActive()) {tx.rollback(); } }" When the servlet is called, the parent is called from the datastore and the child object is created and added to the many to one mapping to the pre-existing parent. The child should automatically be persisted, since the parent is already persistent, and the child is added to the collection of children that map to the parent. And it worked this way in the past. However, to be sure, i did add a pm.makePersistent(child). Doesn't seem to help, still have the intermittent problem. Any suggestions would be appreciated, and if you need to see the actual code I can post. Thanks

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  • Complicated SQL query

    - by Yandawl
    Please bare with me this is difficult to explain xD http://img90.imageshack.us/i/croppercapture1.png/ This is based on an undergraduate degree course where a student takes many units (say 4 core units and 1 optional unit per year). tblAwardCoreUnits and tblAwardOptUnits store which units are optional and core for which award, hence the relationship to tblAward and tblStudentCoreUnits and tblStudentOptUnits store the particular instances of those units which a particular student is taking. Secondly, a unit can have multiple events (say a lecture and a unit) and each of those events has sessions in which a student can attend, hence tblEvents, tblSessions and tblAttendances. The query I am trying to produce is to get a list of all level one students, grouped by their award that lists the percentage of attendances in all the units in the current level. I've tried and tried with this and the following is the best I've managed to come up with so far... I'd REALLY appreciate any help you can give with this! SELECT tblStudents.enrolmentNo, tblStudents.forename, tblStudents.surname, tblAwards.title, (SELECT COUNT((tblAttendances.attended + tblAttendances.authorisedAbsence)) AS SumOfAttendances FROM tblAttendances INNER JOIN (tblStudents ON tblStudents.enrolmentNo = tblAttendances.enrolmentNo)) / FROM tblUnits, tblAwards INNER JOIN ((tblStudents INNER JOIN tblStudentOptUnit ON tblStudents.studentID = tblStudentOptUnit.studentID) INNER JOIN tblStudentCoreUnit ON tblStudents.studentID = tblStudentCoreUnit.studentID) ON tblAwards.awardID = tblStudents.awardID WHERE (((tblStudents.level)="1") AND ((tblStudents.status)="enrolled")) GROUP BY tblAwards.title ORDER BY tblStudents.forname;

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  • Custom Django Field is deciding to work as ForiegnKey for no reason

    - by Joe Simpson
    Hi, i'm making a custom field in Django. There's a problem while trying to save it, it's supposed to save values like this 'user 5' and 'status 9' but instead in the database these fields show up as just the number. Here is the code for the field: def find_key(dic, val): return [k for k, v in dic.items() if v == val][0] class ConnectionField(models.TextField): __metaclass__ = models.SubfieldBase serialize = False description = 'Provides a connection for an object like User, Page, Group etc.' def to_python(self, value): if type(value) != unicode: return value value = value.split(" ") if value[0] == "user": return User.objects.get(pk=value[1]) else: from social.models import connections return get_object_or_404(connections[value[0]], pk=value[1]) def get_prep_value(self, value): from social.models import connections print value, "prep" if type(value) == User: return "user %s" % str(value.pk) elif type(value) in connections.values(): o= "%s %s" % (find_key(connections, type(value)), str(value.pk)) print o, "return" return o else: print "CONNECTION ERROR!" raise TypeError("Value is not connectable!") Connection is just a dictionary with the "status" text linked up to the model for a StatusUpdate. I'm saving a model like this which is causing the issue: Relationship.objects.get_or_create(type="feedback",from_user=request.user,to_user=item) Please can someone help, Many Thanks Joe *_*

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  • After I apply custom logic, next UI action crashes my app.

    - by DanF
    I've got an team (eveningRoster) that I'm making a button add employees to. The team is really a relationship to that night's event, but it's represented with an AC. I wanted to make sure an employee did not belong to the team before it adds, so I added a method to MyDocument to check first. It seems to work, the error logs complete, but after I've added a member, the next time I click anything, the program crashes. Any guesses why? Here's the code: -(IBAction)playsTonight:(id)sender { NSArray *selection = [fullRoster selectedObjects]; NSArray *existing = [eveningRoster arrangedObjects]; //Result will be within each loop. BOOL result; //noDuplicates will stay YES until a duplicate is found. BOOL noDuplicates = YES; //For the loop: int count; for (count = 0; count < [selection count]; count++){ result = [existing containsObject:[selection objectAtIndex:count]]; if (result == YES){ NSLog(@"Duplicate found!"); noDuplicates = NO; } } if (noDuplicates == YES){ [eveningRoster addObjects:[fullRoster selectedObjects]]; NSLog(@"selected objects added."); [eveningTable reloadData]; NSLog(@"Table reloaded."); } [selection release]; [existing release]; return; }

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  • Mapping an instance of IList in NHibernate

    - by Martin Kirsche
    I'm trying to map a parent-child relationship using NHibernate (2.1.2), MySql.Data (6.2.2) and MySQL Server (5.1). I figured out that this must be done using a <bag> in the mapping file. I build a test app which is running without yielding any errors and is doing an insert for each entry but somehow the foreign key inside the children table (ParentId) is always empty (null). Here are the important parts of my code... Parent public class Parent { public virtual int Id { get; set; } public virtual IList<Child> Children { get; set; } } <class name="Parent"> <id name="Id"> <generator class="native"/> </id> <bag name="Children" cascade="all"> <key column="ParentId"/> <one-to-many class="Child"/> </bag> </class> Child public class Child { public virtual int Id { get; set; } } <class name="Child"> <id name="Id"> <generator class="native"/> </id> </class> Program using (ISession session = sessionFactory.OpenSession()) { session.Save( new Parent() { Children = new List<Child>() { new Child(), new Child() } }); } Any ideas what I did wrong?

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  • Liskov Substition and Composition

    - by FlySwat
    Let say I have a class like this: public sealed class Foo { public void Bar { // Do Bar Stuff } } And I want to extend it to add something beyond what an extension method could do....My only option is composition: public class SuperFoo { private Foo _internalFoo; public SuperFoo() { _internalFoo = new Foo(); } public void Bar() { _internalFoo.Bar(); } public void Baz() { // Do Baz Stuff } } While this works, it is a lot of work...however I still run into a problem: public void AcceptsAFoo(Foo a) I can pass in a Foo here, but not a super Foo, because C# has no idea that SuperFoo truly does qualify in the Liskov Substitution sense...This means that my extended class via composition is of very limited use. So, the only way to fix it is to hope that the original API designers left an interface laying around: public interface IFoo { public Bar(); } public sealed class Foo : IFoo { // etc } Now, I can implement IFoo on SuperFoo (Which since SuperFoo already implements Foo, is just a matter of changing the signature). public class SuperFoo : IFoo And in the perfect world, the methods that consume Foo would consume IFoo's: public void AcceptsAFoo(IFoo a) Now, C# understands the relationship between SuperFoo and Foo due to the common interface and all is well. The big problem is that .NET seals lots of classes that would occasionally be nice to extend, and they don't usually implement a common interface, so API methods that take a Foo would not accept a SuperFoo and you can't add an overload. So, for all the composition fans out there....How do you get around this limitation? The only thing I can think of is to expose the internal Foo publicly, so that you can pass it on occasion, but that seems messy.

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  • How do I establish table association in JPA / Hibernate with existing database?

    - by Paperino
    Currently I have two tables in my database Encounters and Referrals: There is a one to many relationship between these two tables. Currently they are linked together with foreign keys. Right now I have public class Encounter extends JPASupport implements java.io.Serializable { @Column(name="referralid", unique=false, nullable=true, insertable=true, updatable=true) public Integer referralid; } But what I really want is public class Encounter extends JPASupport implements java.io.Serializable { .......... @OneToMany(cascade=CascadeType.PERSIST) public Set<Referrals> referral; ............ } So that I can eventually do a query like this: List<Encounter> cases = Encounter.find( "select distinct p from Encounter p join p.referrals as t where t.caseid =103" ).fetch(); How do I tell JPA that even though I have non-standard column names for my foreign keys and primary keys that its the object models that I want linked, not simply the integer value for the keys? Does this make sense? I hope so. Thanks in advanced!

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  • how to model a follower stream in appengine?

    - by molicule
    I am trying to design tables to buildout a follower relationship. Say I have a stream of 140char records that have user, hashtag and other text. Users follow other users, and can also follow hashtags. I am outlining the way I've designed this below, but there are two limitaions in my design. I was wondering if others had smarter ways to accomplish the same goal. The issues with this are The list of followers is copied in for each record If a new follower is added or one removed, 'all' the records have to be updated. The code class HashtagFollowers(db.Model): """ This table contains the followers for each hashtag """ hashtag = db.StringProperty() followers = db.StringListProperty() class UserFollowers(db.Model): """ This table contains the followers for each user """ username = db.StringProperty() followers = db.StringListProperty() class stream(db.Model): """ This table contains the data stream """ username = db.StringProperty() hashtag = db.StringProperty() text = db.TextProperty() def save(self): """ On each save all the followers for each hashtag and user are added into a another table with this record as the parent """ super(stream, self).save() hfs = HashtagFollowers.all().filter("hashtag =", self.hashtag).fetch(10) for hf in hfs: sh = streamHashtags(parent=self, followers=hf.followers) sh.save() ufs = UserFollowers.all().filter("username =", self.username).fetch(10) for uf in ufs: uh = streamUsers(parent=self, followers=uf.followers) uh.save() class streamHashtags(db.Model): """ The stream record is the parent of this record """ followers = db.StringListProperty() class streamUsers(db.Model): """ The stream record is the parent of this record """ followers = db.StringListProperty() Now, to get the stream of followed hastags indexes = db.GqlQuery("""SELECT __key__ from streamHashtags where followers = 'myusername'""") keys = [k,parent() for k in indexes[offset:numresults]] return db.get(keys) Is there a smarter way to do this?

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  • How to link a table to a field a in MySQL server

    - by Nek
    I have this data from a xml file: <?xml version="1.0" encoding="utf-8" ?> <words> <id>...</id> <word>...</word> <meaning>...</meaning> <translation> <ES>...</ES> <PT>...</PT> </translation> </words> This forms the table named "words", which has four fields ("id","word","meaning" and "translation"). On the other hand, the "translation" field can hold several languages like ES,PT,EN,JA,KO,etc... So I create a table ("words.translation", one field is "id" and the others ones are languages ids like "ES","PT",...). I'm sorry for this newby question, but I'd like to know a couple of things about this one-to-many relationship. How to join (or link?) this two tables in MySQL? What information does the "translation" field in the "words" table has to store? How is the sql query to get all the word information (JOIN syntax used?) Thanks for your patience.

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  • How can I set the tab on a webpage depending on which page you come from in ASP.Net MVC?

    - by uriDium
    I have a rather large entity. It has a parent relationship with many different child tables. Each of the child tables I have represented as a tab (luckily it makes sense and looks nice and makes things easier to navigate). If the users wants to add a new child row, they go the particular tab, and there they see a list of rows which is owned by the parent and they can do the usual CRUD. The CRUD takes them to a new controller and action and passes the ID of the parent to the action. (This is as far as I can tell what I was meant to do, any other ideas??) When they have finsihed they click save and it takes them back to the original page BUT I want it to automatically go to the right tab. How can I do this? I am using Jquery UI tabs, ASP.Net MVC 2.0. One idea I had was to just go back to the bookmark (the href part with the #, for e.g. /Parent/Details/4/#tabname). Apparently JQuery UI tabs can handle this. Or to set the tab name as part of the query string (/Parent/Details/4?tab=name) What is the best practise here?

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  • EF 4.0 Code only assocation from abstract to derived

    - by Jeroen
    Using EF 4.0 Code only i want to make an assocation between an abstract and normal class. I have class 'Item', 'ContentBase' and 'Test'. 'ContentBase' is abstract and 'Test' derives from it. 'ContentBase' has a property 'Item' that links to an instance of 'Item'. So that 'Test.Item' or any class that derives from 'ContentBase' has an 'Item' navigation property. In my DB every record for Test has a matching record for Item. public class Item { public int Id { get; set;} } public abstract class ContentBase { public int ContentId { get; set;} public int Id { get; set;} public Item Item { get; set;} } public class Test : ContentBase { public string Name { get; set;} } now some init code public void SomeInitFunction() { var itemConfig = new EntityConfiguration<Item>(); itemConfig.HasKey(p => p.Id); itemConfig.Property(p => p.Id).IsIdentity(); this.ContextBuilder.Configurations.Add(itemConfig); var testConfig = new EntityConfiguration<Test>(); testConfig.HasKey(p => p.ContentId); testConfig.Property(p => p.ContentId).IsIdentity(); // the problem testConfig.Relationship(p => p.Item).HasConstraint((p, q) => p.Id == q.Id); this.ContextBuilder.Configurations.Add(testConfig); } This gives an error: A key is registered for the derived type 'Test'. Keys must be registered for the root type 'ContentBase'. anyway i try i get an error. What am i a doing wrong?

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  • Problem in Saving Multi Level Models in YII

    - by Waqar
    My Table structure for user and his adress detail is as follows CREATE TABLE tbl_users ( id bigint(20) unsigned NOT NULL AUTO_INCREMENT, loginname varchar(128) NOT NULL, enabled enum("True","False"), approved enum("True","False"), password varchar(128) NOT NULL, email varchar(128) NOT NULL, role_id int(20) NOT NULL DEFAULT '2', name varchar(70) NOT NULL, co_type enum("S/O","D/O","W/O") DEFAULT "S/O", co_name varchar(70), gender enum("MALE","FEMALE","OTHER") DEFAULT "MALE", dob date DEFAULT NULL, maritalstatus enum("SINGLE","MARRIED","DIVORCED","WIDOWER") DEFAULT "MARRIED", occupation varchar(100) DEFAULT NULL, occupationtype_id int(20) DEFAULT NULL, occupationindustry_id int(20) DEFAULT NULL, contact_id bigint(20) unsigned DEFAULT NULL, signupreason varchar(500), PRIMARY KEY (id), UNIQUE KEY loginname (loginname), UNIQUE KEY email (email), FOREIGN KEY (role_id) REFERENCES tbl_roles (id), FOREIGN KEY (occupationtype_id) REFERENCES tbl_occupationtypes (id), FOREIGN KEY (occupationindustry_id) REFERENCES tbl_occupationindustries (id), FOREIGN KEY (contact_id) REFERENCES tbl_contacts (id) ) ENGINE=InnoDB; CREATE TABLE tbl_contacts ( id bigint(20) unsigned NOT NULL AUTO_INCREMENT, contact_type enum("cres","pres","coff"), address varchar(300) DEFAULT NULL, landmark varchar(100) DEFAULT NULL, district_id int(11) DEFAULT NULL, city_id int(20) DEFAULT NULL, state_id int(20) DEFAULT NULL, pin_id bigint(20) unsigned DEFAULT NULL, area_id bigint(20) unsigned DEFAULT NULL, po_id bigint(20) unsigned DEFAULT NULL, phone1 varchar(20) DEFAULT NULL, phone2 varchar(20) DEFAULT NULL, mobile1 varchar(20) DEFAULT NULL, mobile2 varchar(20) DEFAULT NULL, PRIMARY KEY (id), FOREIGN KEY (district_id) REFERENCES tbl_districts (id), FOREIGN KEY (city_id) REFERENCES tbl_cities (id), FOREIGN KEY (state_id) REFERENCES tbl_states (id) ) ENGINE=InnoDB; CREATE TABLE tbl_states ( id int(20) NOT NULL AUTO_INCREMENT, name varchar(70) DEFAULT NULL, PRIMARY KEY (id) ) ENGINE=InnoDB; CREATE TABLE tbl_districts ( id int(20) NOT NULL AUTO_INCREMENT, name varchar(70) DEFAULT NULL, state_id int(20) DEFAULT NULL, PRIMARY KEY (id), FOREIGN KEY (state_id) REFERENCES tbl_states (id) ) ENGINE=InnoDB; CREATE TABLE tbl_cities ( id int(20) NOT NULL AUTO_INCREMENT, name varchar(70) DEFAULT NULL, district_id int(20) DEFAULT NULL, state_id int(20) DEFAULT NULL, PRIMARY KEY (id), FOREIGN KEY (district_id) REFERENCES tbl_districts (id), FOREIGN KEY (state_id) REFERENCES tbl_states (id) ) ENGINE=InnoDB; The relationship is as follows User has multiple contacts i.e Permanent Address, Current Address, Office Address. Each Contact has state and City. User-Contact-state like this How to save models of this structure in one go. Please provide a reply ASAP

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  • JPA concatenating table names for parent/child @OneToMany

    - by Robert
    We are trying to use a basic @OneToMany relationship: @Entity @Table(name = "PARENT_MESSAGE") public class ParentMessage { @Id @Column(name = "PARENT_ID") @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer parentId; @OneToMany(fetch=FetchType.LAZY) private List childMessages; public List getChildMessages() { return this.childMessages; } ... } @Entity @Table(name = "CHILD_MSG_USER_MAP") public class ChildMessage { @Id @Column(name = "CHILD_ID") @GeneratedValue(strategy = GenerationType.IDENTITY) private Integer childId; @ManyToOne(optional=false,targetEntity=ParentMessage.class,cascade={CascadeType.REFRESH}, fetch=FetchType.LAZY) private ParentMessage parentMsg; public ParentMessage getParentMsg() { return parentMsg; } ... } ChildMessage child = new ChildMessage(); em.getTransaction().begin(); ParentMessage parentMessage = (ParentMessage) em.find(ParentMessage.class, parentId); child.setParentMsg(parentMessage); List list = parentMessage.getChildMessages(); if(list == null) list = new ArrayList(); list.add(child); em.getTransaction().commit(); We receive the following error. Why is OpenJPA concatenating the table names to APP.PARENT_MESSAGE_CHILD_MSG_USER_MAP? Of course that table doesn't exist.. the tables defined are APP.PARENT_MESSAGE and APP.CHILD_MSG_USER_MAP Caused by: org.apache.openjpa.lib.jdbc.ReportingSQLException: Table/View 'APP.PARENT_MESSAGE_CHILD_MSG_USER_MAP' does not exist. {SELECT t1.CHILD_ID, t1.PARENT_ID, t1.CREATED_TIME, t1.USER_ID FROM APP.PARENT_MESSAGE_CHILD_MSG_USER_MAP t0 INNER JOIN APP.CHILD_MSG_USER_MAP t1 ON t0.CHILDMESSAGES_CHILD_ID = t1.CHILD_ID WHERE t0.PARENTMESSAGE_PARENT_ID = ?} [code=30000, state=42X05]

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  • Having a problem inserting a foreign key data into a table using a PHP form

    - by Gideon
    I am newbee with PHP and MySQL and need help... I have two tables (Staff and Position) in the database. The Staff table (StaffId, Name, PositionID (fk)). The Position table is populated with different positions (Manager, Supervisor, and so on). The two tables are linked with a PositionID foreign key in the Staff table. I have a staff registration form with textfields asking for the relevant attributes and a dynamically populated drop down list to choose the position. I need to insert the user's entry into the staff table along with the selected position. However, when inserting the data, I get the following error (Cannot add or update a child row: a foreign key constraint fails). How do I insert the position selected by the user into the staff table? Here is some of my code... ... echo "<tr>"; echo "<td>"; echo "*Position:"; echo "</td>"; echo "<td>"; //dynamically populate the staff position drop down list from the position table $position="SELECT PositionId, PositionName FROM Position ORDER BY PositionId"; $exeposition = mysql_query ($position) or die (mysql_error()); echo "<select name=position value=''>Select Position</option>"; while($positionarray=mysql_fetch_array($exeposition)) { echo "<option value=$positionarray[PositionId]>$positionarray[PositionName]</option>"; } echo "</select>"; echo "</td>"; echo "</tr>" //the form is processed with the code below $FirstName = $_POST['firstname']; $LastName = $_POST['lastname']; $Address = $_POST['address']; $City = $_POST['city']; $PostCode = $_POST['postcode']; $Country = $_POST['country']; $Email = $_POST['email']; $Password = $_POST['password']; $ConfirmPass = $_POST['confirmpass']; $Mobile = $_POST['mobile']; $NI = $_POST['nationalinsurance']; $PositionId = $_POST[$positionarray['PositionId']]; //format the dob for the database $dobpart = explode("/", $_POST['dob']); $formatdob = $dobpart[2]."-".$dobpart[1]."-".$dobpart[0]; $DOB = date("Y-m-d", strtotime($formatdob)); $newReg = "INSERT INTO Staff (FirstName, LastName, Address, City, PostCode, Country, Email, Password, Mobile, DOB, NI, PositionId) VALUES ('".$FirstName."', '".$LastName."', '".$Address."', '".$City."', '".$PostCode."', '".$Country."', '".$Email."', '".$Password."', ".$Mobile.", '".$DOB."', '".$NI."', '".$PostionId."')"; Your time and help is surely appreciated.

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  • How can I make this LinqToSQL query work? (SqlExecption)

    - by kversch
    The following code gives me an SqlException: OO theCourse = subject.Course; var students = dc.studentsCourses.Where(x = x.course == theCourse).Select(x = x.student); "Invalid object name 'dbo.studentsCourses'." I tried the following code instead but I also get an Exception. My original question was asked on Aardvark and can be read bellow: var allStudents = from s in dc.students select s; List thestudents = new List(); foreach (student s in allStudents) { if (s.courses.Contains(theCourse)) { thestudents.Add(s); } } I did a right click, "run custom tool" on my dbml and checked my names of my tables and entities. The project compiles but I get an Exception at runtime on this line: "if (s.courses.Contains(theCourse))" Any ideas? Original question on Aardvark: How do I do a LinqToSQL query that gives me this: I want to select all students that attended a certain lesson. The lesson is from a certain course. So select the course the lesson is from. Now select all the students that are following that course. There is a many-to-many relationship between the students and the courses table in my DB. I already extended my LINQ entities to be able to select student.Courses and course.Students using this method: http://www.codeproject.com/KB/linq/linq-to-sql-many-to-many.aspx

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