linq

Linq 2 Sybase ASE database? What are the options?

I have a need to query an existing Sybase ASE database and would like to use Linq syntax for my data retrival. I don't need write access, nor do I need the full set of Linq operators, just Select(), SelectMany(), Where(), and GroupJoin() What are options are available? In particular, I'm wondering about nHibernate and building a ne...

Linq subqueries

Hi, I am trying to modify some open source code to change how it filters search results. I want to query by the 'name' of a record instead of it's key. (I have records with duplicate names I want to pull back, but different keys.) This pulls back all the records public static IEnumerable<ticket> GetTickets(stDataContext db, bool? ...

Linq to NHibernate returns different results than HQL?

I have this basic entity setup: public class Instrument { public virtual int Id { get; set; } public virtual Guid? InstrumentGuid { get; set; } public virtual string FIPSCode { get; set; } public virtual IList Names {get; set;} } public class Name { public virtual int Id {get; set;} public virtual string Name {g...

ASP.NET MVC - getting started with Linq and SQL procedure

Today is my first day using ASP.NET MVC, and I'm finding it very intriguing. I only just started learning asp.net. So basically I'm trying to call a procedure from an MSSQL database, and with it I need to send a paramater "PlaceID", which is an integer. This procedure basically just picks out a number of columns from different tables in...

Linq to SQL inheritance patterns

Caveat emptor, I'm new to Linq To SQL. I am knocking up a prototype to convert an existing application to use Linq To SQL for its model (it's an MVVM app). Since the app exists, I can not change its data model. The database includes information on events; these are either advertising events or prize events. As such, the data model inc...

Can I rewrite this LINQ to XML better?

I'm just learning LINQ and in particular LINQ to XML, and I've written up a query that works but I'm wondering if I'm doing it a bit round-a-bout. Can the code be improved? I have an XDocument: <SomeDocument> <Prop1> val1 </Prop1> <Prop2> val2 </Prop2> <Prop3> val3 </Prop3> </SomeDocument> But Prop1, Prop2, and Prop3 ma...

Linq to entities - How to define left join for grouping?

We have two tables - Tasks and TasksUsers (users assigned to task). Task has EntityCollection called TaskUsers. This query returns number of tasks per username: model.TaskCountByAssignee = ( from t in TaskRepository.List() from tu in t.TaskUsers group tu by tu into tug sel...

What to learn next: F# or LINQ

Just started to get my feet wet with C# and .NET, liking it so far. I think I've got the main gist of the C# language constructs, so what technology should I dive into next: F# or LINQ? I'm aiming for both "broadening my horizont" programming-wise AND for "Enhancing my resume" in no particular order. UPDATE: From reading your replies ...

Linq expression

I have 2 lists. The first is a CountryId-list that can look like this 036 208 999 The seccond list is a coundryId to Name list that can look like this: 036, AUSTRALIA 208, DENMARK 380, ITALY 578, NORWAY The result shall be like this: AUSTRALIA DENMARK UNKNOWN ID (999) How can I make a linq query that solves this? ...

Getting MethodInfo without name as string

I'm building SQL expressions from LINQ Expressions and liking it verry much. However an issue with refactoring has come up. Suppose I want to check the Method of a MethodCallExpression, I would do something like this: MethodCallExpression expr = ... // An expression from somewhere... if (expr.Method == typeof(SqlFilterExtensions).Get...

Entity framework and Exists clause

I'm a rookies of EF so, sorry for my perhaps foolish question. I've 2 entities without any relationship (VS does not load the join and I can't manually add it because the primary key of the child uses a derivated key of its parent). Example Entity master Products keys GKey_K, Product_K fields ..... Entity detail GenericInformation ...

Writing 'CONTAINS' query using LINQ

Given the output of query: var queryResult = from o in objects where ... select new { FileName = o.File, Size = o.Size } What would you consider the neatest way to detect if a file is in the queryResult? H...

Create combined DataTable from two DataTables joined with LINQ. C#

I have the following code that fills dataTable1 and dataTable2 with two simple SQL queries, dataTableSqlJoined is filled from the same tables but joined together. I'm trying to write a LINQ query that can create the dataTableLinqJoined as if it had been created using SQL. In my example below, it only returns the values from dataTable1. ...

Finding a single record in a table step-by-step by different requests

There is a table in a databse, let's call this table Document. This table has fields: MajorVersionNumber MinorVersionNumber ReleaseDate There are rules to determine the order of versions and their expiration dates. I'll give the rule of finding expiration date of a version in C# 3 because it looks more easy to read then in English. ...

Paging with LINQ for objects

How would you implement paging in a LINQ query? Actually for the time being, I would be satisfied if the sql TOP function could be imitated. However, I am sure that the need for full paging support comes up sooner later anyway. var queryResult = from o in objects where ... select new ...

Get the the most recent and the one before the most recent item

Hi I have a table with many anniversaries : Date + Name. I want to display the next anniversary and the one after with Linq. How can i build the query ? I use EF Thanks John ...

c# Linq intersect query

If I have an IEnumerable where ClassA exposes an ID property of type long. Is it possible to use a Linq query to get all instances of ClassA with ID belonging to a second IEnumerable? In other words, can this be done? IEnumerable<ClassA> = original.Intersect(idsToFind....)? where original is an IEnumerable and idsToFind is IEnumerabl...

calculate distance with linq or subsonic

i have this MySQL statement from a search page, the user enters there postcode and it finds the nearest stiocklist within 15 MIles of the entered postcode. SELECT * , ( ( ACOS( SIN( "+SENTLNG +" * PI( ) /180 ) * SIN( s_lat * PI( ) /180 ) + COS( " + SENTLNG +" * PI( ) /180 ) * COS( s_lat * PI( ) /180 ) * COS( ( " + SENTLANG + " - s_ln...

how can i query an already loaded data in EF ?

Hi I have an object Customer with a 1-n relationship to Addresses. I want to be able to take the first address. So i create a method: public Address firstAddress { get { var f=from d in this.Addresses select d; return f; } } I get the following error : Error 5 Impossible to find an i...

How Update a node attribute in xml using Linq query?

Hai I have An XDocument .All nodes in this document have an attribute UserId. I want to change the value of this attribute 0 to 1. How to do this using Linq query. I used this. MyNewUserPermission.Descendants("menuNode").Single.SetAttributeValue("userId", Me.UserId) It's not Working.Error shows Sequence contains more than one element...