linq

How does a LINQ extension chain off other extensions

I learned C# back in 2006, and recently tried to get back into it. I have learned then that they added something called LINQ Extensions to C#3.0. Now I am familiar with extension methods, and I'm just pondering the specifics of those related to IEnumerables. Earlier today, me and one of my colleagues were debating whether or not the fol...

Alternatives for NHIbernate?

HI all, What all other libraries or frameworks we can use apart from NHIbernate? Can linq work with entites as the NHIbernate does? Can linq automatically generates entities for us? Does the Data application block come with .NET 3.5 or some separate installation is required? ...

Issue with materialized query result - LINQ

I have a List that includes IQueryAble inside as a property. I'm passing List to my View in MVC project. I iterate through the List using foreach. Inside the foreach: Albums in type of List <% foreach(var x in Albums){%> <h1><%= x.Title %></h1> <p><%= x.Photos.Count() %> </p> <%}%> Displaying the Title is not an issue, but it thro...

How do I select records and summary in one query?

The scenario is like this: name | val 'aa' | 10 'bb' | 20 'cc' | 30 ********* sum | 60 For now I just select all the records in simple LINQ query and invoke the enumerator (ToList()) Then I loop over the list and summarize the val column. Is there a better way? LINQ selects all to a new typed object so I dont know how to add the ...

How to extract the most common YEAR from an array of DateTime objects using LINQ

Hi, im trying to extract the most common YEAR from an array of DateTime objects using LINQ. can someone help me? With the following its telling me i need to implement IComparable.. DateTime modeDate = (from c in dates group c by c.Year into g select g).Max(...

What are the major differences between Data Access Application Block, NHibernate, ADO.NET Entity Framework and LINQ to SQL?

What are the major differences between Data Access Application Block, NHibernate, ADO.NET Entity Framework and LINQ to SQL with respect to performance, business logic, scalability and flexibility? ...

Linq2Entities, many to many and dynamic where clause

Hi, Im fairly new to Linq and struggling using dynamic where over a many to many relationship. Database tables are like so: Products <-> Products_SubCategories <-> SubCategories with Products_SubCategories being a link table. My full linq statement is db.Products.Where("it.SubCategories.SubCategoryID = 2") .In...

query results cannot be enumerated more than once error

Hello I have a problem where I call a stored proedure twice, each with different parameters and I need 2 seperate lists but linq is caching the data and also giving me the error above I have tried 2 different methods to get round the error message, one using ToList() on tbl and the other manually walking through the data My code is sh...

int array to IEnumerable<MyTestObj> ?

I have a MVC that posts an array of int, and I want to convert that array of int's to IEnumerable<MyTestObj>, how is that done? I cant use myintArr.AsEnumerable() it seems. ...

Entity Framework and Link Table issue

Hi, I have a database which consists of the following: ** Table 1 ** Id (PK) Field1 ** Table 2 ** Id (PK) Field2 ** Link Table ** Table1Id (FK) Table2Id (FK) The problem is, I cannot access Table 2 from Table 1, even though the relationship exists in the database. For example, the following should be possible: var Results...

LINQ Expression In Subgroups

public class ErrorLogModel { public int UnitID { get; set; } public string Address { get; set; } public IList<HardwareLogModel> _Hardware { get; set; } } public class SPLHardwareLogModel { public Guid HardwareID { get; set; } public string HardwareDesc { get; set; } public string HardwareStatus { get; set; }...

C# Linq Where Date Between 2 Dates

Hi, I'm trying to get my linq statement to get me all records between two dates, and I'm not quite sure what I need to change to get it to work: (a.Start >= startDate && endDate) var appointmentNoShow = from a in appointments from p in properties from c in clients where a.Id == p.OID && (a.Start.Date >= startDate.Date &&...

Implementing Advanced Filter Page

I have a page which gives user to generate report based on different filters selected. I need some suggestion or idea on my thoughts Loop through each filter control (checkbox, multi select list, radiobox list) and build dynamic where conditions and conjunctions for each filter and then run query Get all the data (i think this will c...

Convert DataTable to Linq

I'm trying to convert DataTable to Linq using DIm result = From r in dt.AsEnumerable() Select new ( col1 = r.Field<integer>("id"), col2 = r.Field<string>("desc")) But i get error near 'new (' saying type expected. What is wrong with this query? ...

Using Linq and C#, trying to get two lists from a list of master items grouped by two inner lists...

Here's the setup: public class Parent { public List<Child> ChildrenA = new List<Child>(); public List<Child> ChildrenB = new List<Child>(); } public class Child { public Child (string name) {Name=name;} public string Name {get;set;} } Having the following data: var parents = new List<Parent>(); parents.Add (new Paren...

Using LinqSql, stored procedure returns datatype image problem

Hello! I´ve got a problem when using LINQ to execute a stored procedure and return its values. One of the column that the stored procedure returns is of datatype image and contains a pdf in binary form.(this because the database is deployed on sql server 2000, otherwised i would choose a blob) When including the stored procedure in my ...

How to convert in Linq statement and assign correct value

Hello Friends, I been trying to write the following code in expression based way but not sure how can i do that assignment to the object after comparison. Any help would be highly appreciated. var pcs = from a in collection group a by a.TotType into g select new { TType = g.Key, SColl = g.Sel...

What does this LINQ query do?

Here are two C# classes... public class Address { public string Country; public string City; } public class Traveller { public string Name; public List<Address> TravelRoute; } ... and a list of data (filled somewhere) ... List<Traveller> Travellers; ... and then this LINQ query: var result = from t in ...

How could I take 1 more item from Linq's TakeWhile?

(line of code of interest is the last one, the rest is just for a full representation) Using the following code, I wanted to take VOTERS until I exceeded the maximum votes needed, but it stops right before reaching that maximum number of votes, so my voters pool has 1 fewer voter than I wanted. Is there a clean way in LINQ where I cou...

Does this code really cause an "access to modified closure" problem?

Taking the following code, Resharper tells me that voicesSoFar and voicesNeededMaximum cause "access to a modified closure". I read about these but what puzzles me here is that Resharper suggests fixing this by extracting the variables to right before the LINQ query. But that is where they are already! Resharper stops complaining if I m...