I want to get the last result returned from this query. How do I do this? Last and LastOrDefault aren't supported by Linq to Sql. var docs = (from d in db.Documents where d.Version > 1 orderby d.DocumentID select new ...
I'm trying to get a handle on if there's a good time to use standard linq keywords or linq extension methods with lambda expressions. They seems to do the same thing, just are written differently. Is it purely a matter of style? var query = from p in Products where p.Name.Contains("foo") orderby c.Name select p; // or wi...
Using LINQ to Entities sounds like a great way to query against a database and get actual CLR objects that I can modify, data bind against and so forth. But if I perform the same query a second time do I get back references to the same CLR objects or an entirely new set? I do not want multiple queries to generate an ever growing number...
Hi, I seem to be in the minority, but to be honest I am not comfortable with linq and don't see any benefits in my personal development (not to say there are no benefits, just a personal opinion based on my situation). I build web applications (.net, .net mvc) and I love having part of my data layer in stored procedures. One thing I l...
We have scalar functions in our database for returning things like "number of tasks for a customer" or "total invoice amount for a customer". We are experimenting and looking to try to do this w/o stored procedures ... normally we would just call this function in our stored procedure and return it as a single value. Is there a way t...
The code below gives an error: Property 'Int32 Key' is not defined for type 'ConsoleApplication1.IKeyed`1[TKey]' when the expression e is created but is fine when func f is created, can anyone explain why and if there is a way to fix it? Module Module1 Sub Main() Dim g = New keyedThingGetter(Of KeyedThing, Integer) ...
How do I utilize a ?: operator in the SELECT clause of a LINQ query? If this can't be done, how can I emulate one? The goal is to get a CASE block in my select clause. As you might suspect, I'm getting an error: Invalid anonymous type member declarator. Anonymous type members must be declared with a member assignment, simple name or m...
Given the following simple example: List<string> list = new List<string>() { "One", "Two", "Three", "three", "Four", "Five" }; CaseInsensitiveComparer ignoreCaseComparer = new CaseInsensitiveComparer(); var distinctList = list.Distinct(ignoreCaseComparer as IEqualityComparer<string>).ToList(); It appears the CaseInsensit...
We have a form that allows a user to filter a list with by typing in a textbox. We need to filter the list based on two fields. The FundName and the CompanyName. When the form loads I put the initial LINQ to SQL results into a list so that for every subsequent action (filter) the database is not hit. This speeds things up significantly (...
Say a class Person +Name: string +Contacts: List<Person> I want to be able to check if a person has a contact with a certain name without having to create a dummy Person instance. person.Contacts.Contains<string>("aPersonName"); This should check all persons in the Contacts list if their Name.Equals("aPersonName"); I see that ...
My query is: var query1 = from u in dc.Usage_Computers.AsEnumerable where u.DomainUser == s3 orderby u.OperationTime descending select new { u.ProgramVersion, u.OperationTime, u.IPaddress, u.ComputerName, ...
I have a requirement to extract a distinct subset of rows from a DataTable, and thought LINQ2DataSets may be a useful and clean way to do this, however it appears that it is not possible to simply identify return rows from a LINQ2DS query as follows var result = from r in fips.AsEnumerable() select r.Field<string>("FACILITY_PROCESS_SUB_...
Say I have two lists: var list1 = new int[] {1, 2, 3}; var list2 = new string[] {"a", "b", "c"}; Is it possible to write a LINQ statement that will generate the following list: var result = new []{ new {i = 1, s = "a"}, new {i = 1, s = "b"}, new {i = 1, s = "c"}, new {i = 2, s = "a"}, new {i = 2, s = "b"}, ne...
I have an object I am using to store document meta data into a table. The body text of the document can be very large, sometimes > 2GB so I will be storing it into a nvarchar(max) field in SQL 2008. I'll use SQL 2008 later to index that field. I won't be using filestreams because they are very restrictive to the database and prevents ...
HI, I have 3 tables: Clips, Books and relationships between ClipBook Problem is: i need get book that has bookID=4 with some clips i mean many-to-many in simple text sql it will be something like this: select * from Clips where clipID in (select clipID from ClipBook where bookID=4) Question is: How can i do this with Linq without o...
how come this work public IQueryable<Category> getCategories(int postId) { subnusMVCRepository<Categories> categories = new subnusMVCRepository<Categories>(); subnusMVCRepository<Post_Category_Map> postCategoryMap = new subnusMVCRepository<Post_Category_Map>(); var query = from c in categories.GetAll() ...
I just watched the last Channel 9 vid on the upcoming parallel extensions to .NET. How would you use this in a web app? I'm specifically thinking of using the parallel Linq extensions against a SQL db. Would this makes sense to use as a way to speed up your data access layer in a multi-user server app? What are the issues (aside from the...
Every time that I change a value in the designer after saving it, the .designer.cs file will be deleted. Can anyone tell me how can I fix this problem? ...
I have a few ASP.Net database front-end websites where MS Access is the back-end. I am trying to use ASP.Net dynamic data website. Should I change this database to SQL Server Express or something else to make it easier or should this work from with MS Access. ...
By convention our DB only alows the use of stored procedures for INSERT, UPDATE and DELETE. For some tables / types there is no DELETE stored procedure, because it is not allowed to delete rows. (You can only update the status of such a type to "deleted"). e.g. a customer may be marked as deleted but is never really removed from the DB. ...