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  • Howw to add new value with generic Repository if there are foreign keys (EF-4)?

    - by Phsika
    i try to write a kind of generic repository to add method. Everything is ok to add but I have table which is related with two tables with FOREIGN KEY.But Not working because of foreign key public class DomainRepository<TModel> : IDomainRepository<TModel> where TModel : class { #region IDomainRepository<T> Members private ObjectContext _context; private IObjectSet<TModel> _objectSet; public DomainRepository() { } public DomainRepository(ObjectContext context) { _context = context; _objectSet = _context.CreateObjectSet<TModel>(); } //do something..... public TModel Add<TModel>(TModel entity) where TModel : IEntityWithKey { EntityKey key; object originalItem; key = _context.CreateEntityKey(entity.GetType().Name, entity); _context.AddObject(key.EntitySetName, entity); _context.SaveChanges(); return entity; } //do something..... } Calling REPOSITORY: //insert-update-delete public partial class AddtoTables { public table3 Add(int TaskId, int RefAircraftsId) { using (DomainRepository<table3> repTask = new DomainRepository<table3>(new TaskEntities())) { return repTask.Add<table3>(new table3() { TaskId = TaskId, TaskRefAircraftsID = RefAircraftsId }); } } } How to add a new value if this table includes foreign key relation

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  • IF I have multiple candidate keys which one is a primary key and justify your choice ??

    - by zahrani
    Given R = { Account , Analyst , Assets, Broker, Client, Commission, Company, Dividend, Exchange, Investment, Office, Profile, Return, Risk_profile, Stock, Volume} and a set of functional dependencies F{fd1, fd2,fd3, fd4, fd5,fd6, fd7, fd8, fd9, fd10, fd11} where: fd1: Client - Office fd2: Stock - Exchange, Dividend fd3: Broker - Profile fd4: Company - Stock fd5: Client - Risk_profile, Analyst fd6: Analyst - Broker fd7: Stock, Broker - Invenstment, Volume fd8: Stock - Company fd9: Investment,Commission - Return fd10: Stock, Broker - Client fd11: Account - Assests these are candidate key(s) : (Account, Commission,Analyst ,Company) (Account, Commission,Analyst ,Stock) (Account ,Commission,Broker ,Company) (Account ,Commission,Broker ,Stock) (Account ,Commission,Client, Company) (Account ,Commission,Client ,Stock) (Q) Select a primary key and justify your choice ? I was select (Account ,Commission,Broker ,Stock) as a primary key ??? I chose that because it has the most direct dependencies compared to other ones. e.g. more attributes are functionally dependent on this primary key. please check if my answer is it true ? or Not I'm waiting your answer asap thank you

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  • How to insert an n:m-relationship with technical primary keys generated by a sequence?

    - by bitschnau
    Let's say I have two tables with several fields and in every table there is a primary key which is a technical id generated by a database sequence: table1 table2 ------------- ------------- field11 <pk> field21 <pk> field12 field22 field11 and field21 are generated by sequences. Also there is a n:m-relationship between table1 und table2, designed in table3: table3 ------------- field11 <fk> field21 <fk> The ids in table1 und table2 are generated during the insert statement: INSERT INTO table1 VALUES (table1_seq1.NEXTVAL, ... INSERT INTO table2 VALUES (table2_seq1.NEXTVAL, ... Therefore I don't know the primary key of the added row in the data-access-layer of my program, because the generation of the pk happens completely in the database. What's the best practice to update table3 now? How can I gain access to the primary key of the rows I just inserted?

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  • Why does cisco IOS require domain-name to be set before SSH keys can be generated?

    - by Daniel Papasian
    Is there a technical reason why IOS requires the device's domain-name to be set (via ip domain-name) before an SSH key can be generated? Is the domain-name used in any way in the generation of the key? Is there any way to force the generation of a key before the domain name is set? UPDATE: Myself (before I posted this question) and others in your answer seem to think it may be used as either a salt or a source of entropy for the key. Wouldn't the domain-name be very predictable? This doesn't seem like a suitable source of entropy.

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  • Find messages from certain key till certain key while being able to remove stale keys.

    - by Alfred
    My problem Let's say I add messages to some sort of datastructure: 1. "dude" 2. "where" 3. "is" 4. "my" 5. "car" Asking for messages from index[4,5] should return: "my","car". Next let's assume that after a while I would like to purge old messages because they aren't useful anymore and I want to save memory. Let's say at time x messages[1-3] became stale. I assume that it would be most efficient to just do the deletion once every x seconds. Next my datastructure should contain: 4. "my" 5. "car" My solution? I was thinking of using a concurrentskiplistset or concurrentskiplist map. Also I was thinking of deleting the old messages from inside a newSingleThreadScheduledExecutor. I would like to know how you would implement(efficiently/thread-safe) this or maybe use a library?

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  • Percentage difference between different values in the same keys of two different arrays.

    - by Paul
    Hey. I'm looking for a solution to this problem. I got 2 arrays, like this: array(2) { [20100526]=> array(1) { ["ga:pageviews"]=> string(5) "19088" } [20100527]=> array(1) { ["ga:pageviews"]=> string(5) "15566" } } array(2) { [20100526]=> array(1) { ["ga:pageviews"]=> string(5) "12043" } [20100527]=> array(1) { ["ga:pageviews"]=> string(5) "11953" } } Now I'd like to create a new array, with the % difference between the values per key. Would be something like this: array(2) { [20100526]=> array(1) { ["ga:pageviews"]=> string(5) "88,23" } [20100527]=> array(1) { ["ga:pageviews"]=> string(5) "74,54" } } Can anyone help me how to create that array?

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  • How do I order by foreign attribute for belongs_to reference where there are 2 keys to foreign table

    - by Will
    I have a Model which has a belongs_to association with another Model as follows class Article belongs_to :author, :class_name => "User" end If I wanted to find all articles for a particular genre ordered by author I would do something like the following articles = Article.all(:includes => [:author], :order => "users.name") However if Article happens to have two references to User how can I sort on :author? class Article belongs_to :editor, :class_name => "User" belongs_to :author, :class_name => "User" end I have tried articles = Article.all(:includes => [:author], :order => "users.name") #=> incorrect results articles = Article.all(:includes => [:author], :order => "authors.name") #=> Exception Thrown

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  • What's the best way to get a bunch of rows from MySQL if you have an array of integer primary keys?

    - by Evan P.
    I have a MySQL table with an auto-incremented integer primary key. I want to get a bunch of rows from the table based on an array of integers I have in memory in my program. The array ranges from a handful to about 1000 items. What's the most efficient query syntax to get the rows? I can think of a few: "SELECT * FROM thetable WHERE id IN (1, 2, 3, 4, 5)" (this is what I do now) "SELECT * FROM thetable where id = 1 OR id = 2 OR id = 3" Multiple queries of the form "SELECT * FROM thetable WHERE id = 1". Probably the most friendly to the query cache, but expensive due to having lots of query parsing. A union, like "SELECT * FROM thetable WHERE id = 1 UNION SELECT * FROM thetable WHERE id = 2 ..." I'm not sure if MySQL caches the results of each query; it's also the most verbose format. I think using the NoSQL interface in MySQL 5.6+ would be the most efficient way to do this, but I'm not yet up to MySQL 5.6.

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  • Rails 3: Create an instance with 3 foreign keys.

    - by donald
    Hello, Having a reviews table: # Table name: reviews # # id :integer not null, primary key # wsp_id :integer # service_id :integer # user_id :integer # description :text # rating :integer # created_at :datetime # updated_at :datetime # belongs_to :wsp belongs_to :service belongs_to :user How can I create a review for a service and pass the wsp_id and user_id? Do I need to use nested routes? I am able to do @user.reviews.new(params[:review]) but I'm not being able of passing the wsp_id and the service_id. Here's my Reviews create controller. def create @review = current_user.reviews.new(params[:review]) if @review.save #Saved else #Error, not saved end end What am I doing wrong? Thank you!

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  • Nested Resource - How to pass needed keys, and attribute to update?

    - by Jason B
    My nested resources are working for form_for updates, but I have a few toggles that I need to setup to change a status field. So I am using link_to, and accessing the url helper. link_to "toggle", edit_project_expense_path(@project[:id],expense_item[:id]) routes.rb resources :projects do resources :expenses end match '/submit_expense/:id' => 'expenses#submit_expense', :as => 'submit_expense' rake routes edit_project_expense GET /projects/:project_id/expenses/:id/edit(.:format) expenses#edit My question is: How can I also send along :approval_status = "1", with my link_to?

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  • How to handle ids and polymorphic associations in views if compound keys are not supported?

    - by duncan
    I have a Movie plan table: movie_plans (id, description) Each plan has items, which describe a sequence of movies and the duration in minutes: movie_plan_items (id, movie_plan_id, movie_id, start_minutes, end_minutes) A specific instance of that plan happens in: movie_schedules (id, movie_plan_id, start_at) However the schedule items can be calculated from the movie_plan_items and the schedule start time by adding the minutes create view movie_schedule_items as select CONCAT(p.id, '-', s.id) as id, s.id as movie_schedule_id, p.id as movie_plan_item_id, p.movie_id, p.movie_plan_id, (s.start_at + INTERVAL p.start_minutes MINUTE) as start_at, (s.start_at + INTERVAL p.end_minutes MINUTE) as end_at from movie_plan_items p, movie_schedules s where s.movie_plan_id=p.movie_plan_id; I have a model over this view (readonly), it works ok, except that the id is right now a string. I now want to add a polymorphic property (like comments) to various of the previous tables. Therefore for movie_schedule_items I need a unique and persistent numeric id. I have the following dilemma: I could avoid the id and have movie_schedule_items just use the movie_plan_id and movie_schedule_id as a compound key, as it should. But Rails sucks in this regard. I could create an id using String#hash or a md5, thus making it slower or collision prone (and IIRC String#hash is no longer persistent across processes in Ruby 1.9) Any ideas on how to handle this situation?

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  • EF Code First, how can I achieve two foreign keys from one table to other table?

    - by Yoo Matsuo
    I've recently downloaded Entity Framework Code First CTP5, and have a trouble with this scenario. I have two tables as follows: Members table ID Name Comments table ID Comment CommentedMemberID CommentMemberID And, the data should be like the following: Members ID Name 1 Mike 2 John 3 Tom Comments ID Comment CommentedMemberID CommentMemberID 1 Good 1 2 2 Good 1 3 3 Bad 2 1 Then, I coded as shown below: public class Member { public int ID {get; set; } public string Name { get; set;} public virtual ICollection Comments { get; set;} } public class Comment { public int ID { get; set; } public string Comment { get; set; } public int CommentedMemberID { get; set; } public int CommentMemberID{ get; set; } public virtual Member CommentedMember { get; set; } public virtual Member CommentMember { get; set; } } public class TestContext : DbContext { public DbSet Members { get; set; } public DbSet Comments { get; set; } } But when I run these models on my cshtml, it gives me errors saying "Cannot create CommentMember instance" or something like that (Sorry, I already changed my models to proceed the EF Code First evaluation, so can't reproduce the same error). I've also tried to use OnModelCreating on the TestContext, but can't find any good instructions and don't know what to do. I saw a blog post of the EF Code First CTP3, and it seems there was a RelatedTo attribute in that version, but now it has gone. Could anyone know how to get it work properly? Or is this a totally wrong way to go with this scenario? Thanks, Yoo

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  • C# form - checkboxes do not respond to plus/minus keys - easy workaround?

    - by Scott
    On forms created with pre dotNET VB and C++ (MFC), a checkbox control responded to the plus/minus key without custom programming. When focus was on the checbox control, pressing PLUS would check the box, no matter what the previous state (checked/unchecked), while pressing MINUS would uncheck it, no matter the previous state. C# winform checkboxes do not seem to exhibit this behavior. Said behavior was very, very handy for automation, whereby the automating program would set focus to a checkbox control and issue a PLUS or MINUS to check or uncheck it. Without this capability, that cannot be done, as the automation program (at least the one I am using) is unable to query the current state of the checkbox (so it can decide whether to issue a SPACE key to toggle the state to the desired one). I've gone over the properties of a checkbox in the Visual Studio 2008 IDE and could not find anything that would restore/enable response to PLUS/MINUS. Since I am in control of the sourcecode for the WinForms in question, I could replace all checkbox controls with a custom checkbox control, but blech, I'd like to avoid that - heck, I don't think I could even consider that given the amount of refactoring that would need to be done. So the bottom line is: does anyone know of a way to get this behavior back more easily than a coding change?

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  • How to avoid Foreign Keys constraints for all tables in DB truncate ?

    - by eugeneK
    Hi, for designing purposes i need to truncate all DB which has lots of FK's. I cannot use DELETE command simply because some tables set with Identity of TinyInts and contain about 150 items. this is a query ( truncate all tables in selected DB ) i'm trying to run Declare @t varchar (1024) Declare tbl_cur cursor for select TABLE_NAME from INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE' OPEN tbl_cur FETCH NEXT from tbl_cur INTO @t WHILE @@FETCH_STATUS = 0 BEGIN EXEC ('TRUNCATE TABLE '+ @t) FETCH NEXT from tbl_cur INTO @t END CLOSE tbl_cur DEALLOCATE tbl_Cur What the best and easiest way to achieve truncate on DB with many FK's ?

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  • Entity diagram with tables that have foreign keys that point to a non-PK column do not show relation

    - by Jason Coyne
    I have two tables parent and child. If I make a foreign key on child that points to the primary key of parent, and then make an entity diagram, the relationship is shown correctly. If I make the foreign key point to a different column, the relationship is not shown. I have tried adding indexes to the column, but it does not have an effect. The database is sqlite, but I am not sure if that has an effect since its all hidden behind ADO.net. How do I get the relationship to work correctly?

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