linq

LINQ list of sublist

I'm trying to get all the sublists that don't inherit from a specified class and also get the parent/root list type. I can't quite figure out the syntax. Here's an example of the sort of thing I'm looking for. Thanks for any help you can give! public class Foo { public IList<Type> Bar { get; private set; } } List<Foo> test = new L...

How can I remove an "ALMOST" Duplicate using LINQ? ( OR SQL? )

This should be and easy one for the LINQ gurus out there. I'm doing a complex Query using UNIONS and CONTAINSTABLE in my database to return ranked results to my application. I'm getting duplicates in my returned data. This is expected. I'm using CONTAINSTABLE and CONTAINS to get all the results I need. CONTAINSTABLE is ranked by SQL a...

Join + IEqualityComparer<T> and HashCode

Im writing my own LINQ reference but Im getting troubles with some of the more complicated operators implementations. There is a Join implementation that takes a IEqualityComparer Im getting just crazy. Im trying to understand it first before I write (obviously) Image this two lists: List<string> initials = new List<string> {"A", "B"...

LinqKit System.InvalidCastException When Invoking method-provided expression on member property.

Given a simple parent/child class structure. I want to use linqkit to apply a child lambda expression on the parent. I also want the Lambda expression to be provided by a utility method. public class Foo { public Bar Bar { get; set; } } public class Bar { public string Value { get; set; } public static Expression<Func<Bar...

Equality between two enumerables

I have two enumerables with the exact same reference elements, and wondering why Equals wouldn't be true. As a side question, the code below to compare each element works, but there must be a more elegant way Cheers, Berryl var other = (ActivityService) obj; if (!AllAccounts.Count().Equals(other.AllAccounts.Count())) return false; for...

RIA Services query: Nested "from" and include children

Hi guys, I have the following schema. What I'd like to do is to retrieve all customers (and children properties) from a selected StaffAssignment by StaffId. So I've written the following query: from c in ObjectContext.Customers.Include("Assignments.Activities") from a in c.Assignments from sa in a.Staff...

Locked DataGridView. Linq is a problem ?

Hi, I get the collection from webservice: var allPlaceHolders = from ph in new MyService().GetPlaceHolders() select new { Code = ph.Code, Name = ph.Name, Related = false }; dgPlaceHoldersAdd.DataSource = allPlaceHolders.ToList(); Designer.cs: this.dgPlaceHoldersAdd.ColumnHeadersHeightSizeMode = System.Windows.Forms.Da...

Linq Projection Question

I'm trying to do the following: from c in db.GetAllContactsQuery() select new { ID= c.ID, LastName = c.LastName, FirstName = c.FirstName, Email = c.Email, City =c.City+" "+c.State } The issue i'm running into is that if c.City or c.State are null, the City property returns null. How can I put a function right beside tha...

LINQ to SQL select distinct from multiple colums

Hi, I'm using LINQ to SQL to select some columns from one table. I want to get rid of the duplicate result also. Dim customer = (From cus In db.Customers Select cus.CustomerId, cus.CustomerName).Distinct Result: 1 David 2 James 1 David 3 Smith 2 James 5 Joe Wanted result: 1 David 2 James 3 Smith 5 Joe Can ...

Need help with this basic Contains<>() extension method and Lambda expressions

Hi, Say I have the following class: class Foo { // ctor etc here public string Bar { get; } } Now, I have a LinkedList of Foos declared like so: LinkedList<Foo> How would I write a basic Contains<>() for this? I want to be able to do this: Foo foo = new Foo(someString); LinkedList<Foo> list = new LinkedLis...

LINQ self referencing query

I have the following SQL query: select p1.[id], p1.[useraccountid], p1.[subject], p1.[message], p1.[views], p1.[parentid], max( case when p2.[created] is null then p1.[created] else p2.[created] end ) as LastUpdate from forumposts p1 left join ( ...

What can map database tables like LINQ to SQL did?

A good thing in LINQ to SQL was a fast and reliable way to map database tables and convert them into classes accessible from c# project. However it is no longer recommended to create projects using LINQ to SQL. What is its substitute? What kind of tool should I use in VS 2010 today if I want to have the same functionality as I had with ...

Which DB? Linq to SQL classes

Hi. I want to develop a multiuser supporting accounting management application in C#. I want to use Linq To SQL classes. LINQ to SQL only supports SQL Server/Compact. However is it possible the SQLite people have written their own LINQ provider given the name of the assembly. I have to use DBMS that is FREE. Which DBMS do you suggest...

Linq to SQL Azure generating Error "Specified cast is not valid."

B"H I have an application that has been working for months using Linq to SQL connecting to a SQLExpress. I tried migrating it to SQL Azure. I copied the structure and data using the Sync Framework. I viewed the data in SQL Azure using SSMS 2008 R2 and it seams to be exactly what I have in my Sql Server. However when I try to use Linq t...

Get Max() record from table by group

Hi, i've got a table like that : Article Number Last Voucher Number Last Voucher Date 0557934 519048 04/02/2005 0557934 519067 04/02/2005 0557934 528630 09/29/2005 0557934 528631 09/29/2005 0557934 529374 10/13/2...

Check if any object in a 2d array is null

I've got an array var cells = new Cell[w, h], can I loop through all cells without a nested for-loop (I want to check if at least one is null)? Ideally I'd want to write something like Debug.Assert(!cells.Contains(null)). ...

Cannot implicitly convert type 'System.Linq.IQueryable<int>' to 'int?'

Hi this is my code var cityList = from country in doc.Element("result").Element("cities").Descendants("city") select new { Name = country.Element("name").Value, Code = country.Element("code").Value, Co...

LINQ - How to change value in select or foreach loop ?

IQueryable items = from rr in _dt.AllItems where rr.ID == ItemID select new{rr.Item, rr.SecondItem}; SecondItem is returning false or true. Is it possible to replace with different string values (for example with On and Off) and add to the items (IQueryable)? ...

The ':' character, hexadecimal value 0x3A, cannot be included in a name

I have an xml file that contains its element like <ab:test>Str</ab:test> When i am trying to access it using the code XElement tempElement = doc.Descendants(XName.Get("ab:test")).FirstOrDefault(); Its giving me error System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Xml.XmlExc...

How to use group by and having count in Linq

I am having trouble trying to convert the following query from SQL to Linq, in particular with the having count and group by parts of the query: select ProjectID from ProjectAssociation where TeamID in ( select TeamID from [User] where UserID in (4)) group by ProjectID having COUNT(TeamID) = (select...