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  • .Net Entity Framework & POCO ... querying full table problem

    - by Chris Klepeis
    I'm attempting to implement a repository pattern with my poco objects auto generated from my edmx. In my repository class, I have: IObjectSet<E> _objectSet; private IObjectSet<E> objectSet { get { if (_objectSet == null) { _objectSet = this._context.CreateObjectSet<E>(); } return _objectSet; } } public IQueryable<E> GetQuery(Func<E, bool> where) { return objectSet.Where(where).AsQueryable<E>(); } public IList<E> SelectAll(Func<E, bool> where) { return GetQuery(where).ToList(); } Where E is the one of my POCO classes. When I trace the database and run this: IList<Contact> c = contactRepository.SelectAll(r => r.emailAddress == "[email protected]"); It shows up in the sql trace as a select for everything in my Contact table. Where am I going wrong here? Is there a better way to do this? Does an objectset not lazy load... so it omitted the where clause? This is the article I read which said to use objectSet's... since with POCO, I do not have EntityObject's to pass into "E" http://devtalk.dk/CommentView,guid,b5d9cad2-e155-423b-b66f-7ec287c5cb06.aspx

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  • query in sql server for retrieving rows

    - by Arash khangaldi
    I have a table that contains the following 4 columns: id name lastname phone I want to write a stored procedure that gets an id as parameter, and then gets the name of that id and then use that name to get all the rows that their name is equal to the names that i found in last step! here it is my query, i know it's wrong but i'm new to sql commands: ALTER PROCEDURE dbo.GetAllNames @id int AS select name as Name from Users where id = @id -- i don't how to retrieve the names that are equal to Name select * from Users where name = Name can you correct my query and help me? Thanks.

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  • How to efficiently handle Where and OrderBy clauses

    - by Goran
    My business layer passes all the required information to UI layer. From what I have read, in general, best practice is to send fetched data to UI layer, and to avoid passing queries like ObjectQuery. My problem with this approach is next: If I am to make a flexible business layer, then I should allow UI to sort the data anyway it requires. Fetching sorted data from database, and then resorting them in UI is kind of bad practice for me, so the only way is to somehow So what are my options? Is there a way to make it like this: public void OrderByMethod(params ...) { .... } so I can call it like this: OrderByMethod(MyEntity.Property1, MyEntity.Property2 descending....); Thanks, Goran

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  • Getting error in MVC Proj while writing Lambda Expression

    - by Shrewd Demon
    hi, i am creating a sample movie (MVC) application. I was getting fine with Viewing and Creating a new record, but when i wrote the code to get the details of a particular record i met with the following error: Unable to cast objec`t of type 'System.Data.Objects.ObjectQuery`1[MovieApp.Models.Movie]' to type 'MovieApp.Model`s.Movie'. here is the code i wrote for getting the details public ActionResult Details(int id) { var moviedetail = (Movie)_entities.MovieSet.Where(mvid => mvid.Id == id); return View(moviedetail); } can any body tell me whats going wrong and where ?? thank you.

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  • Join two list comparing their elements properties

    - by 100r
    public class Person() { int ID; string Name; DateTime ChangeDate } var list1 = new List<Person> { new Person { ID= 1, Name = "Peter", ChangeDate= "2011-10-21" }, new Person { ID= 2, Name = "John", ChangeDate= "2011-10-22" }, new Person { ID= 3, Name = "Mike", ChangeDate= "2011-10-23" }, new Person { ID= 4, Name = "Dave", ChangeDate= "2011-10-24" } }; var list2 = new List<Person> { new Person { ID= 1, Name = "Pete", ChangeDate= "2011-10-21" }, new Person { ID= 2, Name = "Johny", ChangeDate= "2011-10-20" }, new Person { ID= 3, Name = "Mikey", ChangeDate= "2011-10-24" }, new Person { ID= 5, Name = "Larry", ChangeDate= "2011-10-27" } }; As output I would like to have list1 + list2 = Person { ID= 1, Name = "Peter", ChangeDate= "2011-10-21" }, Person { ID= 2, Name = "John", ChangeDate= "2011-10-22" }, Person { ID= 3, Name = "Mikey", ChangeDate= "2011-10-24" }, Person { ID= 4, Name = "Dave", ChangeDate= "2011-10-24" } Person { ID= 5, Name = "Larry", ChangeDate= "2011-10-27" } And the Algorithm is like this. Join two list. If elements of lists have same ID, compare them by ChangeDate and take the ond with bigger date. If ChangeDate are equeal take any of them but not both. Maybe its easier to concat both lists and than to filter them with lambda. I tried, but always came out with some ugly code :/ Anyone have any idea?

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  • Should I return IEnumerable<T> or IQueryable<T> from my DAL?

    - by Gary '-'
    I know this could be opinion, but I'm looking for best practices. As I understand, IQueryable implements IEnumerable, so in my DAL, I currently have method signatures like the following: IEnumerable<Product> GetProducts(); IEnumerable<Product> GetProductsByCategory(int cateogoryId); Product GetProduct(int productId); Should I be using IQueryable here? What are the pros and cons of either approach? Note that I am planning on using the Repository pattern so I will have a class like so: public class ProductRepository { DBDataContext db = new DBDataContext(<!-- connection string -->); public IEnumerable<Product> GetProductsNew(int daysOld) { return db.GetProducts() .Where(p => p.AddedDateTime > DateTime.Now.AddDays(-daysOld )); } } Should I change my IEnumerable<T> to IQueryable<T>? What advantages/disadvantages are there to one or the other?

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  • what is a performance way to 'tree-walking' through my Entity Framework data

    - by Greg
    Hi, I have a Entity Framework design with a few tables that define a "graph". So there can be a large chain of relationships between objects in the few tables via concept of parent/child relationships. What is a performance way to 'tree-walking' through my Entity Framework data? That is I assume I wouldn't want to load the full set of all NODES and RELATIONSHIPS from the database for the purpose of walking the tree, where the end result may only be identifying leaf nodes? Or would this be OK with the way lazy loading may work at the column/parameter level? Else how could I load just the skeleton of the objects and then when needing to refer to any attributes have them lazy load then?

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  • IEnumerable.Cast not calling cast overload

    - by Martin Neal
    I'm not understanding something about the way .Cast works. I have an explicit (though implicit also fails) cast defined which seems to work when I use it "regularly", but not when I try to use .Cast. Why? Here is some compilable code that demonstrates my problem. public class Class1 { public string prop1 { get; set; } public int prop2 { get; set; } public static explicit operator Class2(Class1 c1) { return new Class2() { prop1 = c1.prop1, prop2 = c1.prop2 }; } } public class Class2 { public string prop1 { get; set; } public int prop2 { get; set; } } void Main() { Class1[] c1 = new Class1[] { new Class1() {prop1 = "asdf",prop2 = 1}}; //works Class2 c2 = (Class2)c1[0]; //doesn't work: Compiles, but throws at run-time //InvalidCastException: Unable to cast object of type 'Class1' to type 'Class2'. Class2 c3 = c1.Cast<Class2>().First(); }

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  • Which O/RM tool supports Microsofts Access?

    - by Steven
    For one of my clients I'm currently building an application that communicates with a legacy Microsoft Access database. Migrating to SQL server is unfortunately not (yet) an option. I currently write the queries using OleDbConnection, OleDbCommand and –good old- text based queries. As you can imagine I'm a bit spoiled by using modern O/RM tools and I feel like I went back in time. Which O/RM tool supports Microsoft Access so I can get rid of this uglyness?

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  • What is the correct method to load an XML file and re-write it as a CSV?

    - by codesmack
    I have a XML file that I want to load into an unknown object type. (I say unknown object type because I am not sure what direction to go) Once I have the data loaded I need to do some processing on certain elements that are now loaded into the new object. For sake of example, we can say that the xml file is full of elements named <car> and within the car element I need to process the <mileage> element. Then once this is all done I need to write the file as a CSV file. I would like to do this is the most direct way possible. (The less code the better) I am using VS 2008 C#

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  • ASP.net MVC3 entities, don't know how to count

    - by Spedax
    I have 2 tables, 1 with countries, 1 with states. The states table has a column with Population. I'm using entities and I have created a List of states for the countries public class TblCountries { //Entities for my table country ... public List<tblStates> States { get; set; } } So now I can for example List all the states that belong to a country. Now what I want to do is count the population, so I can show the population that of an entire country. I tried using in my view @foreach (var item in Model.Countries) { @Html.DisplayFor(modelItem => item.States.Count<population>) } But this doesn't work, anyone know how to do this? Thanks in advanced!

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  • Is there an automatic way to generate a rollback script when inserting data with LINQ2SQL?

    - by Jedidja
    Let's assume we have a bunch of LINQ2SQL InsertOnSubmit statements against a given DataContext. If the SubmitChanges call is successful, is there any way to automatically generate a list of SQL commands (or even LINQ2SQL statements) that would automatically undo everything that was submitted? It's like executing a rollback even though everything worked as expected. Note: The destination database will either be Oracle or SQL Server, so if there is specific functionality for both databases that will achieve this, I'm happy to use that as well.

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  • Testing a (big) collection retrieved from a db

    - by Bas
    I'm currently doing integration testing on a live database and I have the following sql statement: var date = DateTime.Parse("01-01-2010 20:30:00"); var result = datacontext.Repository<IObject>().Where(r => r.DateTime > date).First(); Assert.IsFalse(result.Finished); I need to test if the results retrieved from the statement, where the given date is less then the date of the object, have Finished set to False. I do not know how many results I get back and currently I'm getting the first object of the list and check if that object has Finished set to false. I know testing only the first item of the list is not valid testing, as a solution for that I could iterate through the list and check all items on Finished, but putting logic in a Test is kinda going against the concept of writing 'good' tests. So my question is: Does anyone have a good solution of how to properly test the results of this list?

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  • How to report DataContext.SubmitChanges() progress with LINQ2SQL

    - by kzen
    If there is a foreach loop that contains DataContext.Customer.InsertOnSubmit(cust) for example: foreach (Object obj in collection) { Customer cust = new Customer { Id = obj.Id, Name = obj.Name ... }; DataContext.Customer.InsertOnSubmit(cust); } And outside of the loop there is a call to: DataContext.SubmittChanges(); Is there a way to obtain the SubmittChanges progress in order to report the progress back to the user (or a different approach without moving the SubmittChanges into the loop)?

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  • ASP.Net Gridview paging, pageindex always == 0.

    - by David Archer
    Hi all, Having a slight problem with my ASP.Net 3.5 app. I'm trying to get the program to pick up what page number has been clicked. I'm using ASP.Net's built in AllowPaging="True" function. It's never the same without code, so here it is: ASP.Net: <asp:GridView ID="GridView1" runat="server" CellPadding="4" ForeColor="#333333" GridLines="Vertical" Width="960px" AllowSorting="True" EnableSortingAndPagingCallbacks="True" AllowPaging="True" PageSize="25" > <RowStyle BackColor="#F7F6F3" ForeColor="#333333" /> <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" /> <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" /> <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" /> <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" /> <EditRowStyle BackColor="#999999" /> <AlternatingRowStyle BackColor="White" ForeColor="#284775" /> </asp:GridView> C#: var fillTable = from ft in db.IncidentDatas where ft.pUserID == Convert.ToInt32(ClientList.SelectedValue.ToString()) select new { Reference = ft.pRef.ToString(), Date = ft.pIncidentDateTime.Value.Date.ToShortDateString(), Time = ft.pIncidentDateTime.Value.TimeOfDay, Premesis = ft.pPremises.ToString(), Latitude = ft.pLat.ToString(), Longitude = ft.pLong.ToString() }; if (fillTable.Count() > 0) { GridView1.DataSource = fillTable; GridView1.DataBind(); var IncidentDetails = fillTable.ToList(); for (int i = 0; i < IncidentDetails.Count(); i++) { int pageno = GridView1.PageIndex; int pagenostart = pageno * 25; if (i >= pagenostart && i < (pagenostart + 25)) { //Processing } } } Any idea why GridView1.PageIndex is always = 0? The thing is, the processing works correctly for the grid view.... it will always go to the correct paging page, but it's always 0 when I try to get the number. Help!

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  • Timeout LinqToSql inserting millions of records

    - by Bas
    I'm inserting approximently 3 million records in a database using this solution. Eventually when the application has been inserting records for a while (my last run lasted around 4 hours), it gives a timeout with the following SqlException: "SqlExcepetion: Timeout expired. The timeoutperiod elapsed prior to completion of the operation or the server is not responding." What's the best way to handle this exception? Is there a way to prevent this from happening or should I catch the exception? Thanks in advance!

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  • Linq2Sql Best Practices

    - by this. __curious_geek
    I'm recently migrating to Linq2Sql and all my future projects will be using Linq2Sql. Having said that, I researched a lot on how to properly plug-in Linq2Sql in application design. what to put at what layer ? How do you design your repositories and business layer services ? Should I use DTOs over Linq2Sql entities on interaction layer ? what things should I be careful about ? what problems did you face ? I did not find any rock-solid material that really talked about one single thing and everyone have their own opinions. I'm looking forward to your ideas on how to integrate/use Linq2Sql in projects. My priority is maintenance[it should be maintenable and when multiple people work on same project] and scalabilty [it should have scope of evolution]. Thanks.

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  • How do I convert int? into int

    - by Richard77
    Hello, I've create a SPROC that saves an object and returns the id of the new object saved. Now, I'd like to return an int not an int? public int Save(Contact contact) { int? id; context.Save_And_SendBackID(contact.FirstName, contact.LastName, ref id); //How do I return an int instead of an int? } Thanks for helping

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  • retrivenewly inserted record ID with Linq2SQL

    - by devmania
    hi, i am using the following private BlogDataContext db = new BlogDataContext (); article.Created = DateTime.UtcNow; article.Modified = DateTime.UtcNow; db.Articles.InsertOnSubmit(article); db.SubmitChanges( ); int id = article.Id; i am wondering is this save, i mean will it give me the Id of the article user inserted or will there be case of concurrences if another user update the article in fraction of second of second after this user ? thanks in advanced.

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  • .Net Reflection - Calling unexisting methods

    - by Joaozinho das Couves
    Lets say i call method M1 on class A using reflection. The method does not exist. Is there any way to put a handler on class A that says, "someone is trying to execute method M1"? Or Is it possible to add a method dinamically to a class? I want to add a method M1...Mn that always does MyStaticClass.DoAction("M1...Mn"); Something like: string methodName = "M1". A.AddMethod(methodname,x = MyStaticClass.DoAction(x)); Thanks

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  • I want to create a common unit test function to check all functions based on parameter

    - by Nilesh Rathod
    I want to create a common unit test function to check all functions based on parameter for e.g commonmethod(string methodname,string paramter1,....) { .... } what logic should i write inside this method so that by passing a actual function in parameter methodname and then the common method should execute that function and should return the output. i am using entity framework for all functions which has been created in my project and now i dont want to create a separate unit test function for each function.just one function should do the job based on different parameters... is that possible.. ?, if so then please provide me an code for same.. Thanks in advance..!!!

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  • How do I guarante node order for an Xpath 'OR' query

    - by Tom Carter
    I have a snippet of XML that looks like <body> Some text.... <nodeA>....</nodeA> more text <someOtherNode> <nodeA>.......</nodeA> </someOtherNode> <nodeB>.......</nodeB> etc..... </body> I'm selecting all nodeA and NodeB nodes inside <body> using an XPATH query similar to "//nodeA|//nodeB" As I understand it, .NET supports XPATH 1.0 which does not guarantee node order. How can I guarantee selected nodes are returned in document order in my OR query : that's to say : nodeA, nodeA, nodeB

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