Search Results

Search found 32925 results on 1317 pages for 'linq to object'.

Page 37/1317 | < Previous Page | 33 34 35 36 37 38 39 40 41 42 43 44  | Next Page >

  • Sort collection within collection using Linq

    - by user327066
    Hi, I have a one-to-many Linq query and I would like to sort on a property within the "many" collection. For example in the pseudo-code below, I am returned a List from the Linq query but I would like to sort / order the Products property based on the SequenceNumber property of the Product class. How can I do this? Any information is appreciated. Thanks. class Order { int OrderId; List<Product> Products; } class Product { string name; int SequenceNumber; }

    Read the article

  • Linq To SQL: Retain list order when using .Contains

    - by rockinthesixstring
    I'm using Lucene.net to build a MyListOfIds As List(Of Integer) which I then pass on to my Linq service. I then search the database as follows Return _EventRepository.Read().Where(Function(e) MyListOfIds.Contains(e.ID)).ToList Now I know that Lucene is already ordering MyListOfIds based on the weight it gave each term. What sucks is that Linq is losing that order in it's SQL search. My Question: How can I retain that sort order when building my Lambda expression? I tried using LINQPad to see how the query is being built, but because I had to declare a variable LINQPad didn't show me the resultant SQL :-( Here's what I tried in LINQPad Dim i As New List(Of Integer) i.Add(1) i.Add(100) i.Add(15) i.Add(3) i.Add(123) Dim r = (From e In Events Where i.Contains(e.ID) Select e) note: my example is in VB.NET, but I don't mind if responses are in C#

    Read the article

  • Duplicate a database record with linq

    - by holz
    Is there a way to duplicate a db record with linq to sql in c#? Id [int] IDENTITY(1,1) NOT NULL PRIMARY KEY, [Foo] [nvarchar](255) NOT NULL, [Bar] [numeric](28,12) NOT NULL, ... Given the table above, I would like to duplicate a record (but give it a different id), in a way that new fields added to the DB and the Linq dbml file at a later date will still get duplicated with out having to change that code that duplicates the record. ie I don't want to write newRecord.Foo = currentRecord.Foo; for all of the fields on the table.

    Read the article

  • Multiple fields from LINQ to Text Box

    - by Chuki2
    how can I pass value from selected field (LINQ) to textbox in winforms? If single fields, I just do like this var result = from row in dtValueBranch.AsEnumerable() where row.Field<int>("branchID") == idBranch select row.Field<string>("branchName"); StringBuilder sb = new StringBuilder(); foreach (string s in result) { sb.Append(s + Environment.NewLine); } tbBranch.Text = sb.ToString(); So this is the code LINQ to many fields var result = from row in dtValueBranch.AsEnumerable() where row.Field<int>("branchID") == idBranch select new { BranchName = row["branchName"].ToString(), branchTel = row["branchTel1"].ToString(), // And many more fields }; How can I to implement each fields to each textbox?

    Read the article

  • LINQ to SQL auto-generated type for stored procedure

    - by StuffHappens
    Hello. I have the following stored procedure ALTER PROCEDURE [dbo].Test AS BEGIN CREATE TABLE ##table ( ID1 int, ID2 int ) DECLARE @query varchar(MAX); INSERT INTO ##table VALUES(1, 1); SELECT * FROM ##table; END And I try to use it from C# code. I use LINQ to SQL as an O/RM. When I add the procedure to DataBaseContext it says that it can't figure out the return value of this procedure. How to modify the stored procedure so that I can use it with LINQ to SQL. Note: I need to have global template table!

    Read the article

  • Building a linked list with LINQ

    - by FreshCode
    What is the fastest way to order an unordered list of elements by predecessor (or parent) element index using LINQ? Each element has a unique ID and the ID of that element's predecessor (or parent) element, from which a linked list can be built to represent an ordered state. Example ID | Predecessor's ID --------|-------------------- 20 | 81 81 | NULL 65 | 12 12 | 20 120 | 65 The sorted order is {81, 20, 12, 65, 120}. An (ordered) linked list can easily be assembled iteratively from these elements, but can it be done in fewer LINQ statements? Edit: I should have specified that IDs are not necessarily sequential. I chose 1 to 5 for simplicity. See updated element indices which are random.

    Read the article

  • Where Not In OR Except simulation of SQL in LINQ to Object(C#)

    - by Thinking
    Suppose I have two lists that holds the list of source file names and destination file names respectively. The Sourcefilenamelist has files as 1.txt, 2.txt,3.txt, 4.txt while the Destinaitonlist has 1.txt,2.txt. I ned to write a linq query to find out which files are in SourceList that are absent in DestinationFile list. e.g. here the out put will be 3.txt and 4.txt. I have done this by a foreach statement.. but now I want to do the same by using LINQ(C#). Help needed. Thanks

    Read the article

  • Doing a UNION ALL on two different COUNTs using Linq-To-Sql

    - by Danno
    Is it possible to write a linq-to-sql statement that will return two different COUNTs that have been put into a single dataset using UNION ALL? I know this is syntactically wrong but here's what I'm trying to do: (from t1 in TableOne select t1).Count().Union( (from t2 in TableTwo select t2).Count() ) Here's the sql I would like would like to have generated: select count(*) from TableOne union all select count(*) from TableTwo I realize that Count() returns an int and does not have a Union method on it and therein lies my question. Can Linq-to-Sql be written that will achieve what I'm after?

    Read the article

  • Linq Order By a subtable

    - by Michael
    Hello, My question is how to sort a Linq query by a sub table: Table Apps: - app_id - name Table AppStatus: - app_status_id - app_id - severity - status_date I would like to have a query with all the apps, sorted by the last status severity: app_id name 1 first 2 second 3 third app_status_id app_id severity status_date 1 1 5 12-4-2010 2 1 2 15-4-2010 3 2 7 10-4-2010 4 3 3 13-4-2010 Now i want it sorted like: app_id name 3 third 1 first 2 second Can anyone help me with a LINQ query for this. I tried the following already, but that didn't work: var apps = from apps in dc.Apps orderby apps.AppStatus.LastOrDefault().severity select apps;

    Read the article

  • Transform LINQ Dataset into a Matrix for export

    - by Mad Halfling
    Hi folks, I've got a data table with columns in which include Item, Category and Value (and others, but those are the only relevant ones for this problem) that I access via LINQ in a C# ASP.Net MVC app. I want to transform these into a matrix and output that as a CSV file to pull into Excel as matrix with the items down the side, the categories across the top and the values in the row cells. However, I don't know how many, or what, categories there will be in this table, nor will there always be a record for each item/category combination. I've written this by looping round, getting my "master category" list, then looking again for each item, filling in either blank or Value, depending on whether the item/category record exists, but as there are currently 27000 records in the table, this isn't as fast as I'd like. Is there a slicker and faster way I can do this, maybe via LINQ (firing into a quicker SQL statement so the DB server can do the leg-work), or will any method essentially come back to what I am doing? Thx MH

    Read the article

  • Use LINQ to insert data from dataset to SQL

    - by Mayo
    Let's say I have a dataset in an ASP.NET website (.NET 3.5) with 5 tables, each has roughly 30,000 rows and an average of 12 columns. I want to insert all of the data from the dataset into 5 very-similar-but-not-quite-identical tables in SQL Server 2008. I also want to use LINQ (personal preference - trying to learn something new). Is it as simple as iterating through the dataset and, for each row, creating a new instance of the associated class, initializing its data with the dataset's row, adding it to the data model, and then doing one giant SubmitChanges at the end? Are there better ways of doing this with LINQ? Or is this the de-facto standard?

    Read the article

  • How does linq decide between inner & outer joins

    - by user287795
    Hi Usually linq is using an left outer join for its queries but on some cases it decides to use inner join instead. I have a situation where that decision results in wrong results since the second table doesn't always have suitable records and that removes the records from the first table. I'm using a linqdatasource over a dbml where the relevant tables are identical but one holds historical records removed from the first. both have the same primary key. and I'm using a dataloadoption to load both tables at once with out round trips. Would you explain why linq decided to use an inner join here? Thanks

    Read the article

  • stepping into a linq query

    - by MyNameIsJob
    Is it possible to step into a linq query? I have a linq to entity framework 4 query in it's simplest form: List = List.Where(f => f.Value.ToString().ToLowerInvariant().Contains(filter.ToLowerInvariant())); It's a query against an Entity Framework DbContext and I'm having trouble seeing why it works for something like: List searching for 001 yields no results against the following list Test001 Test002 Test003 Test004 However any other search yields results (Such as t00 or Test) I was hoping to figure out a way to see the resulting sql but it appears that I need Intellitrace, which I don't currently have or possibly stepping through the query itself and see each iteration build itself.

    Read the article

  • What's the benefit of object-oriented programming over procedural programming?

    - by niko
    I'm trying to understand the difference between procedural languages like C and object-oriented languages like C++. I've never used C++, but I've been discussing with my friends on how to differentiate the two. I've been told C++ has object-oriented concepts as well as public and private modes for definition of variables: things C does not have. I've never had to use these for while developing programs in Visual Basic.NET: what are the benefits of these? I've also been told that if a variable is public, it can be accessed anywhere, but it's not clear how that's different from a global variable in a language like C. It's also not clear how a private variable differs from a local variable. Another thing I've heard is that, for security reasons, if a function needs to be accessed it should be inherited first. The use-case is that an administrator should only have as much rights as they need and not everything, but it seems a conditional would work as well: if ( login == "admin") { // invoke the function } Why is this not ideal? Given that there seems to be a procedural way to do everything object-oriented, why should I care about object-oriented programming?

    Read the article

  • Questioning the motivation for dependency injection: Why is creating an object graph hard?

    - by oberlies
    Dependency injection frameworks like Google Guice give the following motivation for their usage (source): To construct an object, you first build its dependencies. But to build each dependency, you need its dependencies, and so on. So when you build an object, you really need to build an object graph. Building object graphs by hand is labour intensive (...) and makes testing difficult. But I don't buy this argument: Even without dependency injection, I can write classes which are both easy to instantiate and convenient to test. E.g. the example from the Guice motivation page could be rewritten in the following way: class BillingService { private final CreditCardProcessor processor; private final TransactionLog transactionLog; // constructor for tests, taking all collaborators as parameters BillingService(CreditCardProcessor processor, TransactionLog transactionLog) { this.processor = processor; this.transactionLog = transactionLog; } // constructor for production, calling the (productive) constructors of the collaborators public BillingService() { this(new PaypalCreditCardProcessor(), new DatabaseTransactionLog()); } public Receipt chargeOrder(PizzaOrder order, CreditCard creditCard) { ... } } So dependency injection may really be an advantage in advanced use cases, but I don't need it for easy construction and testability, do I?

    Read the article

  • Is the Entity Component System architecture object oriented by definition?

    - by tieTYT
    Is the Entity Component System architecture object oriented, by definition? It seems more procedural or functional to me. My opinion is that it doesn't prevent you from implementing it in an OO language, but it would not be idiomatic to do so in a staunchly OO way. It seems like ECS separates data (E & C) from behavior (S). As evidence: The idea is to have no game methods embedded in the entity. And: The component consists of a minimal set of data needed for a specific purpose Systems are single purpose functions that take a set of entities which have a specific component I think this is not object oriented because a big part of being object oriented is combining your data and behavior together. As evidence: In contrast, the object-oriented approach encourages the programmer to place data where it is not directly accessible by the rest of the program. Instead, the data is accessed by calling specially written functions, commonly called methods, which are bundled in with the data. ECS, on the other hand, seems to be all about separating your data from your behavior.

    Read the article

  • Why can't Java servlet sent out an object ?

    - by Frank
    I use the following method to send out an object from a servlet : public void doGet(HttpServletRequest request,HttpServletResponse response) throws IOException { String Full_URL=request.getRequestURL().append("?"+request.getQueryString()).toString(); String Contact_Id=request.getParameter("Contact_Id"); String Time_Stamp=Get_Date_Format(6),query="select from "+Contact_Info_Entry.class.getName()+" where Contact_Id == '"+Contact_Id+"' order by Contact_Id desc"; PersistenceManager pm=null; try { pm=PMF.get().getPersistenceManager(); // note that this returns a list, there could be multiple, DataStore does not ensure uniqueness for non-primary key fields List<Contact_Info_Entry> results=(List<Contact_Info_Entry>)pm.newQuery(query).execute(); Write_Serialized_XML(response.getOutputStream(),results.get(0)); } catch (Exception e) { Send_Email(Email_From,Email_To,"Check_License_Servlet Error [ "+Time_Stamp+" ]",new Text(e.toString()+"\n"+Get_Stack_Trace(e)),null); } finally { pm.close(); } } /** Writes the object and CLOSES the stream. Uses the persistance delegate registered in this class. * @param os The stream to write to. * @param o The object to be serialized. */ public static void writeXMLObject(OutputStream os,Object o) { // Classloader reference must be set since netBeans uses another class loader to loead the bean wich will fail in some circumstances. ClassLoader oldClassLoader=Thread.currentThread().getContextClassLoader(); Thread.currentThread().setContextClassLoader(Check_License_Servlet.class.getClassLoader()); XMLEncoder encoder=new XMLEncoder(os); encoder.setExceptionListener(new ExceptionListener() { public void exceptionThrown(Exception e) { e.printStackTrace(); }}); encoder.writeObject(o); encoder.flush(); encoder.close(); Thread.currentThread().setContextClassLoader(oldClassLoader); } private static ByteArrayOutputStream writeOutputStream=new ByteArrayOutputStream(16384); /** Writes an object to XML. * @param out The boject out to write to. [ Will not be closed. ] * @param o The object to write. */ public static synchronized void writeAsXML(ObjectOutput out,Object o) throws IOException { writeOutputStream.reset(); writeXMLObject(writeOutputStream,o); byte[] Bt_1=writeOutputStream.toByteArray(); byte[] Bt_2=new Des_Encrypter().encrypt(Bt_1,Key); out.writeInt(Bt_2.length); out.write(Bt_2); out.flush(); out.close(); } public static synchronized void Write_Serialized_XML(OutputStream Output_Stream,Object o) throws IOException { writeAsXML(new ObjectOutputStream(Output_Stream),o); } At the receiving end the code look like this : File_Url="http://"+Site_Url+App_Dir+File_Name; try { Contact_Info_Entry Online_Contact_Entry=(Contact_Info_Entry)Read_Serialized_XML(new URL(File_Url)); } catch (Exception e) { e.printStackTrace(); } private static byte[] readBuf=new byte[16384]; public static synchronized Object readAsXML(ObjectInput in) throws IOException { // Classloader reference must be set since netBeans uses another class loader to load the bean which will fail under some circumstances. ClassLoader oldClassLoader=Thread.currentThread().getContextClassLoader(); Thread.currentThread().setContextClassLoader(Tool_Lib_Simple.class.getClassLoader()); int length=in.readInt(); readBuf=new byte[length]; in.readFully(readBuf,0,length); byte Bt[]=new Des_Encrypter().decrypt(readBuf,Key); XMLDecoder dec=new XMLDecoder(new ByteArrayInputStream(Bt,0,Bt.length)); Object o=dec.readObject(); Thread.currentThread().setContextClassLoader(oldClassLoader); in.close(); return o; } public static synchronized Object Read_Serialized_XML(URL File_Url) throws IOException { return readAsXML(new ObjectInputStream(File_Url.openStream())); } But I can't get the object from the Java app that's on the receiving end, why ? The error messages look like this : java.lang.ClassNotFoundException: PayPal_Monitor.Contact_Info_Entry Continuing ... java.lang.NullPointerException: target should not be null Continuing ... java.lang.NullPointerException: target should not be null Continuing ... java.lang.NullPointerException: target should not be null Continuing ...

    Read the article

  • Cannot convert lambda expression to type 'string' because it is not a delegate type

    - by RememberME
    I have the following code written by another developer on 2 pages of my site. This used to work just fine, but now is giving the error "Cannot convert lambda expression to type 'string' because it is not a delegate type" on the Delete line with Ajax.ThemeRollerActionLink. I don't go into this section of the site often, and we recently upgraded from MVC 1.0 to 2.0. I'm guessing that's probably when it stopped working. I've looked up this error and the recommended fix seems to be add using System.Linq However, the page already has <%@ Import Namespace="System.Linq" %> <% Html.Grid(Model).Columns(col => { col.For(c => "<a href='" + Url.Action("Edit", new { userName = c }) + "' class=\"fg-button fg-button-icon-solo ui-state-default ui-corner-all\"><span class=\"ui-icon ui-icon-pencil\"></span></a>").Named("Edit").DoNotEncode(); col.For(c => Ajax.ThemeRollerActionLink("fg-button fg-button-icon-solo ui-state-default ui-corner-all", "ui-icon ui-icon-close", "Delete", new { userName = c }, new AjaxOptions { Confirm = "Delete User?", HttpMethod = "Delete", InsertionMode = InsertionMode.Replace, UpdateTargetId = "gridcontainer", OnSuccess = "successDeleteAssignment", OnFailure = "failureDeleteAssignment" })).Named("Delete").DoNotEncode(); col.For(c => c).Named("User"); }).Attributes(id => "userlist").Render(); %>

    Read the article

< Previous Page | 33 34 35 36 37 38 39 40 41 42 43 44  | Next Page >