Search Results

Search found 4738 results on 190 pages for 'linq'.

Page 85/190 | < Previous Page | 81 82 83 84 85 86 87 88 89 90 91 92  | Next Page >

  • Dynamic Data with Subsonic 3

    - by Ezequiel Bertti
    i want to make a webproject with Subsonic and Dynamic Data... But when i go register the ContextData a don't have it in subsonic with LINQ... in Global.asax.cs a have to do something like this model.RegisterContext(SubSonicRepo, new ContextConfiguration() { ScaffoldAllTables = true }); how can i make it work? have some way to make it work? using entities or LINQ everything work... but using Subsonic with linq it not work...

    Read the article

  • Passing integer lists in a sql query, best practices

    - by Artiom Chilaru
    I'm currently looking at ways to pass lists of integers in a SQL query, and try to decide which of them is best in which situation, what are the benefots of each, and what are the pitfalls, what should be avoided :) Right now I know of 3 ways that we currently use in our application. 1) Table valued parameter: Create a new Table Valued Parameter in sql server: CREATE TYPE [dbo].[TVP_INT] AS TABLE( [ID] [int] NOT NULL ) Then run the query against it: using (var conn = new SqlConnection(DataContext.GetDefaultConnectionString)) { var comm = conn.CreateCommand(); comm.CommandType = CommandType.Text; comm.CommandText = @" UPDATE DA SET [tsLastImportAttempt] = CURRENT_TIMESTAMP FROM [Account] DA JOIN @values IDs ON DA.ID = IDs.ID"; comm.Parameters.Add(new SqlParameter("values", downloadResults.Select(d => d.ID).ToDataTable()) { TypeName = "TVP_INT" }); conn.Open(); comm.ExecuteScalar(); } The major disadvantages of this method is the fact that Linq doesn't support table valued params (if you create an SP with a TVP param, linq won't be able to run it) :( 2) Convert the list to Binary and use it in Linq! This is a bit better.. Create an SP, and you can run it within linq :) To do this, the SP will have an IMAGE parameter, and we'll be using a user defined function (udf) to convert this to a table.. We currently have implementations of this function written in C++ and in assembly, both have pretty much the same performance :) Basically, each integer is represented by 4 bytes, and passed to the SP. In .NET we have an extension method that convers an IEnumerable to a byte array The extension method: public static Byte[] ToBinary(this IEnumerable intList) { return ToBinaryEnum(intList).ToArray(); } private static IEnumerable<Byte> ToBinaryEnum(IEnumerable<Int32> intList) { IEnumerator<Int32> marker = intList.GetEnumerator(); while (marker.MoveNext()) { Byte[] result = BitConverter.GetBytes(marker.Current); Array.Reverse(result); foreach (byte b in result) yield return b; } } The SP: CREATE PROCEDURE [Accounts-UpdateImportAttempts] @values IMAGE AS BEGIN UPDATE DA SET [tsLastImportAttempt] = CURRENT_TIMESTAMP FROM [Account] DA JOIN dbo.udfIntegerArray(@values, 4) IDs ON DA.ID = IDs.Value4 END And we can use it by running the SP directly, or in any linq query we need using (var db = new DataContext()) { db.Accounts_UpdateImportAttempts(downloadResults.Select(d => d.ID).ToBinary()); // or var accounts = db.Accounts .Where(a => db.udfIntegerArray(downloadResults.Select(d => d.ID).ToBinary(), 4) .Select(i => i.Value4) .Contains(a.ID)); } This method has the benefit of using compiled queries in linq (which will have the same sql definition, and query plan, so will also be cached), and can be used in SPs as well. Both these methods are theoretically unlimited, so you can pass millions of ints at a time :) 3) The simple linq .Contains() It's a more simple approach, and is perfect in simple scenarios. But is of course limited by this. using (var db = new DataContext()) { var accounts = db.Accounts .Where(a => downloadResults.Select(d => d.ID).Contains(a.ID)); } The biggest drawback of this method is that each integer in the downloadResults variable will be passed as a separate int.. In this case, the query is limited by sql (max allowed parameters in a sql query, which is a couple of thousand, if I remember right). So I'd like to ask.. What do you think is the best of these, and what other methods and approaches have I missed?

    Read the article

  • Import Namespace System.Query

    - by GateKiller
    I am trying to load Linq on my .Net 3.5 enabled web server by adding the following to my .aspx page: <%@ Import Namespace="System.Query" %> However, this fails and tells me it cannot find the namespace. The type or namespace name 'Query' does not exist in the namespace 'System' I have also tried with no luck: System.Data.Linq System.Linq System.Xml.Linq I believe that .Net 3.5 is working because var hello = "Hello World" seems to work. Can anyone help please? Cheers, Stephen PS: I just want to clarify that I don't use Visual Studio, I simple have a Text Editor and write my code directly into .aspx files.

    Read the article

  • LinqKit stack overflow exception using predicate builder

    - by MLynn
    I am writing an application in C# using LINQ and LINQKit. I have a very large database table with company registration numbers in it. I want to do a LINQ query which will produce the equivalent SQL: select * from table1 where regno in('123','456') The 'in' clause may have thousands of terms. First I get the company registration numbers from a field such as Country. I then add all the company registration numbers to a predicate: var predicate = PredicateExtensions.False<table2>(); if (RegNos != null) { foreach (int searchTerm in RegNos) { int temp = searchTerm; predicate = predicate.Or(ec => ec.regno.Equals(temp)); } } On Windows Vista Professional a stack overflow exception occured after 4063 terms were added. On Windows Server 2003 a stack overflow exception occured after about 1000 terms were added. I had to solve this problem quickly for a demo. To solve the problem I used this notation: var predicate = PredicateExtensions.False<table2>(); if (RegNosDistinct != null) { predicate = predicate.Or(ec => RegNos.Contains(ec.regno)); } My questions are: Why does a stack overflow occur using the foreach loop? I take it Windows Server 2003 has a much smaller stack per process\thread than NT\2000\XP\Vista\Windows 7 workstation versions of Windows. Which is the fastest and most correct way to achieve this using LINQ and LINQKit? It was suggested I stop using LINQ and go back to dynamic SQL or ADO.NET but I think using LINQ and LINQKit is far better for maintainability.

    Read the article

  • Cast MyEntity To LinqEntity throw a base controller class

    - by Mohammad Kani
    hi there i design a multilayer we appliction andusing LINQ a my data provider i need to user my own Entites instead o LINQ etities. so i created Entities Project and create my entities in it. when i get data from contex and cast them to my entities , everything is ok. but when i want to cast on of my entities to linq entity , an exception thrown. in my linq entity i add CTYPE operator from and to my entities Exp : Public Class BaseController(Of LinqEntity As {BaseEntity, New}, MyEntity As ModuleEntities.BaseEntityInfo) Implements Interfaces.Base(Of ServiceEntity) 'This methd work fine and cast LinqEntity to MyEntity Public Function GetAll() As List(Of MyEntity ) Dim q = (From x In Context.GetTable(Of LinqEntity)() _ Select x).Cast(Of MyEntityBase) End Function Public Sub Update(ByVal entity As MyEntity) 'here is problem 'cast , direct cast , or anything not work Dim x as LinqEntity = entity Me.Context.GetTable(Of LinqEntity).InsertOnSubmit(entity) Me.Context.SubmiChanges() End Sub

    Read the article

  • extracting only elements with text (or value)

    - by guy
    hay all. i am trying to transform html to xml meaning extracting all elements with text using this code is not working maybe some one has the answer ? System.Xml.Linq.XElement query1 = new System.Xml.Linq.XElement("RawHTMLData", from q in hDoc.Descendants("TABLE") where q.HasElements select new System.Xml.Linq.XElement("TABLE" + (++i).ToString(), from j in q.Elements("TR") where j.HasElements && j.Descendants("div") != null select new System.Xml.Linq.XElement("Row", from hh in j.Descendants("div") where tt => j.Descendants("div").Contains(hh.Value) select(TT(hh)))));

    Read the article

  • How to reflect over T to build an expression tree for a query?

    - by Alex
    Hi all, I'm trying to build a generic class to work with entities from EF. This class talks to repositories, but it's this class that creates the expressions sent to the repositories. Anyway, I'm just trying to implement one virtual method that will act as a base for common querying. Specifically, it will accept a an int and it only needs to perform a query over the primary key of the entity in question. I've been screwing around with it and I've built a reflection which may or may not work. I say that because I get a NotSupportedException with a message of LINQ to Entities does not recognize the method 'System.Object GetValue(System.Object, System.Object[])' method, and this method cannot be translated into a store expression. So then I tried another approach and it produced the same exception but with the error of The LINQ expression node type 'ArrayIndex' is not supported in LINQ to Entities. I know it's because EF will not parse the expression the way L2S will. Anyway, I'm hopping someone with a bit more experience can point me into the right direction on this. I'm posting the entire class with both attempts I've made. public class Provider<T> where T : class { protected readonly Repository<T> Repository = null; private readonly string TEntityName = typeof(T).Name; [Inject] public Provider( Repository<T> Repository) { this.Repository = Repository; } public virtual void Add( T TEntity) { this.Repository.Insert(TEntity); } public virtual T Get( int PrimaryKey) { // The LINQ expression node type 'ArrayIndex' is not supported in // LINQ to Entities. return this.Repository.Select( t => (((int)(t as EntityObject).EntityKey.EntityKeyValues[0].Value) == PrimaryKey)).Single(); // LINQ to Entities does not recognize the method // 'System.Object GetValue(System.Object, System.Object[])' method, // and this method cannot be translated into a store expression. return this.Repository.Select( t => (((int)t.GetType().GetProperties().Single( p => (p.Name == (this.TEntityName + "Id"))).GetValue(t, null)) == PrimaryKey)).Single(); } public virtual IList<T> GetAll() { return this.Repository.Select().ToList(); } protected virtual void Save() { this.Repository.Update(); } }

    Read the article

  • DeleteOnSubmit doesnt exist?

    - by Anders Metnik
    using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data; Thats my namespaces.. i was looking for System.Data.Linq; but it doesnt seem to be anywhere, and i guess that is what have been moved to System.Linq, since i have access to most other things in Linq. EDIT: found System.Data:Linq, no difference Here is my method: public void deleteStudienummer(int studienummer) { dbcontent = new DBEntities(); var dQry = from members in dbcontent.Medlemmer where members.Studienummer == studienummer select members; foreach (var member in dQry) { dbcontent.*** } dbcontent.AcceptAllChanges(); Console.WriteLine("delete member should have occured"); } The * was supposed to be DeleteOnSubmit, but i only have DeleteDatabase and DeleteObject, i tried with object but it doesnt work.. Have also tried dbcontent.Medlemmer.* but still not present. And AcceptAllChanges() was supposed to be .submitChanges() but that wasnt present either.

    Read the article

  • LINQ. Grouping by days. How to do this easily?

    - by punkouter
    I can't seem to find any god reference on this. I have alot of data in SQL with dates. So I wanted to make a line chart to show this data over time. If I want to show it over a perioud of days then I need to group by days.. But the LOGDATE is the full date.. not the DAY.. So I have this below.. but LINQ doesnt know what 'DayOfYear' property is.. HELP var q = from x in dc.ApplicationLogs let dt = x.LogDate group x by new { dayofyear = dt.Value.DayOfYear } into g select new { iCount = g.Count(), strDate = g.Key };

    Read the article

  • How to use Linq with Castle ActiveRecord

    - by Ronnie Overby
    I am playing around with Castle ActiveRecord and noticed that the download included the file, Castle.ActiveRecord.Linq.dll. I haven't found any documentation for using Linq with ActiveRecord, only some old blog posts. What is the usage pattern? Is Castle.ActiveRecord.Linq ready for production use? I'm using reflector, pending an answer.

    Read the article

  • Extracting the Date from a DateTime in Entity Framework 4 and LINQ

    - by Ken Cox [MVP]
    In my current ASP.NET 4 project, I’m displaying dates in a GridDateTimeColumn of Telerik’s ASP.NET Radgrid control. I don’t care about the time stuff, so my DataFormatString shows only the date bits: <telerik:GridDateTimeColumn FilterControlWidth="100px"   DataField="DateCreated" HeaderText="Created"    SortExpression="DateCreated" ReadOnly="True"    UniqueName="DateCreated" PickerType="DatePicker"    DataFormatString="{0:dd MMM yy}"> My problem was that I couldn’t get the built-in column filtering (it uses Telerik’s DatePicker control) to behave.  The DatePicker assumes that the time is 00:00:00 but the data would have times like 09:22:21. So, when you select a date and apply the EqualTo filter, you get no results. You would get results if all the time portions were 00:00:00. In essence, I wanted my Entity Framework query to give the DatePicker what it wanted… a Date without the Time portion. Fortunately, EF4 provides the TruncateTime  function. After you include Imports System.Data.Objects.EntityFunctions You’ll find that your EF queries will accept the TruncateTime function. Here’s my routine: Protected Sub RadGrid1_NeedDataSource _     (ByVal source As Object, _      ByVal e As Telerik.Web.UI.GridNeedDataSourceEventArgs) _     Handles RadGrid1.NeedDataSource     Dim ent As New OfficeBookDBEntities1     Dim TopBOMs = From t In ent.TopBom, i In ent.Items _                   Where t.BusActivityID = busActivityID _       And i.BusActivityID And t.ItemID = i.RecordID _       Order By t.DateUpdated Descending _       Select New With {.TopBomID = t.TopBomID, .ItemID = t.ItemID, _                        .PartNumber = i.PartNumber, _                        .Description = i.Description, .Notes = t.Notes, _                        .DateCreated = TruncateTime(t.DateCreated), _                        .DateUpdated = TruncateTime(t.DateUpdated)}     RadGrid1.DataSource = TopBOMs End Sub Now when I select March 14, 2011 on the DatePicker, the filter doesn’t stumble on time values that don’t make sense. Full Disclosure: Telerik gives me (and other developer MVPs) free copies of their suite.

    Read the article

  • Crazy Linq: performing System.ComponentModel.DataAnnotations validation in a single statement

    - by Daniel Cazzulino
    public static IEnumerable&lt;ValidationResult&gt; Validate(object component) { return from descriptor in TypeDescriptor.GetProperties(component).Cast&lt;PropertyDescriptor&gt;() from validation in descriptor.Attributes.OfType&lt;System.ComponentModel.DataAnnotations.ValidationAttribute&gt;() where !validation.IsValid(descriptor.GetValue(component)) select new ValidationResult( validation.ErrorMessage ?? string.Format(CultureInfo.CurrentUICulture, "{0} validation failed.", validation.GetType().Name), new[] { descriptor.Name }); } ...Read full article

    Read the article

  • Fixing LINQ Error: Sequence contains no elements

    - by ChrisD
    I’ve read some posts regarding this error when using the First() or Single() command.   They suggest using FirstOrDefault() or SingleorDefault() instead. But I recently encountered it when using a Sum() command in conjunction with a Where():   Code Snippet var effectiveFloor = policies.Where(p => p.PricingStrategy == PricingStrategy.EstablishFloor).Max(p => p.Amount);   When the Where() function eliminated all the items in the policies collection, the Sum() command threw the “Sequence contains no elements” exception.   Inserting the DefaultIfEmpty() command between the Where() and Sum(), prevents this error: Code Snippet var effectiveFloor = policies.Where(p => p.PricingStrategy == PricingStrategy.EstablishFloor).DefaultIfEmpty().Max(p => p.Amount);   but now throws a Null Reference exception!   The Fix: Using a combination of DefaultIfEmpty() and a null check in the Sum() command solves this problem entirely: Code Snippet var effectiveFloor = policies.Where(p => p.PricingStrategy == PricingStrategy.EstablishFloor).DefaultIfEmpty().Max(p =>  p==null?0 :p.Amount);

    Read the article

  • How to profile LINQ to Entities queries in your asp.net applications - part 3

    - by nikolaosk
    In this post I will continue exploring ways on how to profile database activity when using the Entity Framework as the data access layer in our applications. If you want to read the first post of the series click here . If you want to read the second post of the series click here . In this post I will use the excellent (best tool for EF profiling) which is called Entity Framework Profiler. You can download the trial - fully functional edition of this tool from here . I will use the previous example...(read more)

    Read the article

  • How to profile LINQ to Entities queries in your asp.net applications - part 2

    - by nikolaosk
    In this post I will continue exploring ways on how to profile database activity when using the Entity Framework as the data access layer in our applications. I will use a simple asp.net web site and EF to demonstrate this. If you want to read the first post of the series click here . In this post I will use the Tracing Provider Wrappers which extend the Entity framework. You can download the whole solutions/samples project from here .The providers were developed from Jaroslaw Kowalski . 1) Unzip...(read more)

    Read the article

  • Cannot .Count() on IQueryable (NHibernate)

    - by Bruno Reis
    Hello, I'm with an irritating problem. It might be something stupid, but I couldn't find out. I'm using Linq to NHibernate, and I would like to count how many items are there in a repository. Here is a very simplified definition of my repository, with the code that matters: public class Repository { private ISession session; /* ... */ public virtual IQueryable<Product> GetAll() { return session.Linq<Product>(); } } All the relevant code in the end of the question. Then, to count the items on my repository, I do something like: var total = productRepository.GetAll().Count(); The problem is that total is 0. Always. However there are items in the repository. Furthermore, I can .Get(id) any of them. My NHibernate log shows that the following query was executed: SELECT count(*) as y0_ FROM [Product] this_ WHERE not (1=1) That must be that "WHERE not (1=1)" clause the cause of this problem. What can I do to be able .Count() the items in my repository? Thanks! EDIT: Actually the repository.GetAll() code is a little bit different... and that might change something! It is actually a generic repository for Entities. Some of the entities implement also the ILogicalDeletable interface (it contains a single bool property "IsDeleted"). Just before the "return" inside the GetAll() method I check if if the Entity I'm querying implements ILogicalDeletable. public interface IRepository<TEntity, TId> where TEntity : Entity<TEntity, TId> { IQueryable<TEntity> GetAll(); ... } public abstract class Repository<TEntity, TId> : IRepository<TEntity, TId> where TEntity : Entity<TEntity, TId> { public virtual IQueryable<TEntity> GetAll() { if (typeof (ILogicalDeletable).IsAssignableFrom(typeof (TEntity))) { return session.Linq<TEntity>() .Where(x => (x as ILogicalDeletable).IsDeleted == false); } else { return session.Linq<TEntity>(); } } } public interface ILogicalDeletable { bool IsDeleted {get; set;} } public Product : Entity<Product, int>, ILogicalDeletable { ... } public IProductRepository : IRepository<Product, int> {} public ProductRepository : Repository<Product, int>, IProductRepository {} Edit 2: actually the .GetAll() is always returning an empty result-set for entities that implement the ILogicalDeletable interface (ie, it ALWAYS add a WHERE NOT (1=1) clause. I think Linq to NHibernate does not like the typecast.

    Read the article

< Previous Page | 81 82 83 84 85 86 87 88 89 90 91 92  | Next Page >