Hi I have recently started off with LINQ and its amazing. I was wondering if LINQ would allow me to apply a function - any function - to all the elements of a collection, without using foreach. Something like python lambda functions. For example if I have a int list, Can I add a constant to every element using LINQ If i have a DB tabl...
Hello, I have a linq query which returns the ID of a question based on the questions text. This ID is then needed to be used to relate a date in a date table to that particular question. The question is already stored and the date is stored at a different time. The problem is that the query returns the questionID as an anonymous type a...
I have a huge IQueryable that I want to export directly to Excel for data dumps, how would I do this? I was trying to put it into a GridView and export from there, which works if I use only a chunk of the data, but if I use the whole IQueryable, nothing happens. This is a table with 4k rows and each row has 70 or so columns. Edit: CSV...
I have a exchange rate table. I need to get current rate and previous rate and then compare results. I can get first record using FirstOrDefault. When i using ElementAtOrDefault,error show "The query operator 'ElementAtOrDefault' is not supported". How can i get second record? ...
I am trying to construct a LINQ query, with expression trees, to do the following: I have a field in my ItemCode table called Labels, an example of the data contained in this field is "lamps lighting chandelier". I want to allow the user to type in some text, i.e. "Red Lamp", and be able to search the Labels field, of the ItemCode, tab...
Hi, I have a simple select from a typed dataset: var productlist = from prds in dsProducts.sk_products.AsEnumerable() join prdcat in dsProducts.sk_productscategories.AsEnumerable() on prds.Field<int>("productid") equals prdcat.Field<int>("productid") where prdcat.Field<int>("categoryid") == categoryid ...
Hi. I have a small problem where I want to find the next "active" item in a list with linq. Then next "active" item is defined by a startDate and EndDate. Here is an example list. //-- Create Lists of turns IList<Turn> turns= new List<Turn>(){ new Turn(){Name = "Turn 1", StartDate = DateTime.Parse("2009-05-...
I have two tables which have a column in common , how can I retreive the first table where the values of it's column are not equal to the values of the column of the other table? Here is an example: table1ID | foo | fooBool table2ID | foo | fooin ---------------------------- ----------------------------- ...
Using Linq To XML, how can I get the space_id value (720) from the xml below? I am reading this but I think the namespace in the xml is my stumbling block. <r25:spaces xmlns:r25="http://www.collegenet.com/r25" pubdate="2009-05-05T12:18:18-04:00"> <r25:space id="VE1QOjRhMDAyZThhXzFfMWRkNGY4MA==" crc="" status="new"> <r25:space_id>...
Hello, Is there any function in F# similar to LINQ fluent syntax for sorting by multiple expressions: myList.OrderBy(fun x->x.Something).ThenBy(fun x->x.SomethingElse) I'd love something like: myList |> Seq.sort_by(fun x->x.Something) |> Seq.then_by(fun x->x.SomethingElse) Thx ...
I'm trying to build a way to get the key for a given piece of text in a given resx file at runtime. Currently, I can open and read the file (Using ResXResourceReader) but I have to use a foreach to go over the entire file. This could be a performance issue, as some of our resx files are fairly large (in the order of 2000 strings) and w...
After answering this question I put together the following C# code just for fun: public static IEnumerable<int> FibonacciTo(int max) { int m1 = 0; int m2 = 1; int r = 1; while (r <= max) { yield return r; r = m1 + m2; m1 = m2; m2 = r; } } foreach (int i in FibonacciTo(56).Where...
Is it possible to select all controls that inherit a particular abstract class with linq. ...
I'd like to do a subtraction of sets based on criteria. A pseudo-query would look like: select table1.columnn1 ,table1.column2 from table1, table2 where (table1.column1.value1 not in table2.column1 and table1.column2.value2 not in table2.column2) I can make it to about here: dim list = From tbl1 In table1 Whe...
Is there a way to return a random row from a table using LINQToSQL? ...
Say I've got an array of User: class User : IUserDowngraded { public Int32 Id { get; set; } } ... with downgraded functionality done by casting the objects to a specific interface: interface IUserDowngraded { Int32 Id { get; } // removes set functionality from property } ... how would I cast those downgraded objects (IUserD...
I am working on an employee-scheduling system. I think I have the database setup pretty well, and have run into a snag on pulling the data for my database and getting it onto the page. I am using LINQ to make things easy on myself. Here is the Object Relational Map. Here is my Linq select statement: protected void LinqSelecting(object...
Hi, I am using LINQ to SQL in an ASP.NET project. While inserting the table I need to convert the values to the particular table object and I need to insert. For that I created a new constructor in that table with parameter so that I can assign my value to that table object , the assign the functionality is working but while inserti...
Hello, I have a Question table which joins to a Solution table. The solutions are linked to the questions but in order to delete a question, i must delete the solutions for that question first and then delete the question itself. I have a linq query that retrieves all solutions for a specified question however i am unsure how to proceed...
Say I create two sets of tuples like so: Dim losSPResults As List(Of spGetDataResults) = m_dcDataClasses.spGetData.ToList Dim loTupleKeys = From t In losSPResults Select t.key1, t.key2 '' Query on an existing dataset: Dim loTupleExistingKeys = from t in m_losSPResults Select t.key3, t.key4 Now I want to perform set op...