Consider this code:
var query = (from a in db.Table
where a = SomeCondition
select a.SomeNumber).AsEnumerable();
int recordCount = query.Count();
int totalSomeNumber = query.Sum();
decimal average = query.Average();
Assume "query" takes a very long time to run. I need to get the record count, total SomeNumbe...
In C#
var parameters =
from line in parameterTextBox.Lines
select new {name = line.Split(' ').First(), value = line.Split(' ').Skip(1)};
Is there a way to do this without having to split twice?
...
I have the following table structure:
CREATE TABLE [Report].[MesReport](
[MesReportID] [int] IDENTITY(1,1) NOT NULL,
[ParentID] [int] NOT NULL,
[ReportTitle] [nvarchar](80) NOT NULL,
[ReportName] [nvarchar](80) NOT NULL,
[DatabaseServer] [nvarchar](80) NOT NULL,
[DatabaseName] [nvarchar](50) NOT NULL,
[Login]...
I'm trying to ask my OData service:
"Give me all the Products that do not have a Category"
with the Products and Category have a m2m relationship.
I've tried:
from p in Products
where p.Categories == null
select p
and
from p in Products
where !p.Categories.Any()
select p
and
from p in Products
where p.Categories.Count == 0...
I'm sure this is a trivial question but I couldn't find a good example. Suppose all you want to do is change one attribute for all objects in a list. I'd like to say something like:
List<SomeType> list = ...;
list.Select(x => x { x.Name = "Foo" } );
Notice the absence of the "new" keyword. I don't want to recreate objects that alread...
I have this function:
public static IQueryable<Article> WhereArticleIsLive(this IQueryable<Article> q)
{
return q.Where(x =>
x != null
&& DateTime.UtcNow >= x.PublishTime
&& x.IsPublished
&& !x.IsDeleted);
}
And it works just fine in this query:
from a in Articles.WhereArticleIsLive()
where a.Id ==...
I am trying to convert a DataTable to an IEnumerable. Where T is a custom type I created. I know I can do it by creating a List but I was think there was a slicker way to do it using IEnumerable. Here is what I have now.
private IEnumerable<TankReading> ConvertToTankReadings(DataTable dataTable)
{
var tankReadings = n...
I have a IEnumerable collection of objects. The objects have a field LastedUpdated which is a DateTime field.
I want to filter the collection, given a timestamp that I have, to return the record in the collection with that timestamp and the "next record" in time (based on this field) because I then want to have some code do a "diff" be...
I'm trying to construct my linq-to-sql expression so that it only generates a single SQL database query. The query involves two nested selects, a simplifed verion is:
var query = from person in People
where person.ID == 1234
select new PersonDetails()
{
ID = person.ID,
...
Hi!
This may be a newbie question...
In my code I can easily use "where Obj.Feld = String", but using "where Obj.Feld.StartsWith("a")" doesn't work. See the following two functions:
Public Function EntriesByFileName(ByRef Database() As Entry, ByVal Filename As _
String) As IEnumerable(Of Entry)
Dim Result As IEnumerable...
Hello all,
I want to group by the categoryid and then do a count on this. But I don't know how to do this. I have tried a couple of ways without success. Here is my latest:
public class Count
{
public int TradersCount { get; set; }
public int Id { get; set; }
public string Description { get; set; }
}
public IQu...
Forgive me if this has been asked already. I've only just started using LINQ. I have the following Expression:
public static Expression<Func<TblCustomer, CustomerSummary>> SelectToSummary()
{
return m => (new CustomerSummary()
{
ID = m.ID,
CustomerName = m.CustomerName,
LastSalesContact = // This is a Per...
Hello,
I have the following code
new Dictionary<string,IEnumerable<Control>>()
{ {"view1", new Control[] { contents, building, view1 }},
{"view2", new Control[] { contents, view2 }},
{"view3", new Control[] { building, view3 }
}});
How do I get a list of...
I'm iterating the tables of a context and then the properties of those tables to eager load all columns in a context. I received some help via another question, but I don't seem to be able to figure out how to iterate the column properties of the actual table.
Final working code:
public static void DisableLazyLoading(this DataContext...
It seems I am having a bit of trouble with Linq to XML, I have looked for tutorials, but nothing really tells me about from, select, statements. I would like to know how to do a foreach/if statements with linq, if you have a tutorial please let me know. My problem right now is I only want a certain part put into my XML if the textbox h...
I was trying to do something like this -
List<short> listofshorts= new List<short>();
int s = listofshorts.Sum();
//this does not work...but same code works for a list of ints..
I got this compilation error -
'System.Collections.Generic.List' does not contain a definition for 'Sum' and the best extension method overload 'System.L...
This is giving me a headache. I have this link query here that grabs an ID
Dim mclassID = From x In db.SchoolClasses Where x.VisitDateID = _visitdateID Select x.ClassID
And then later on I have this linq query
ViewData("Staff") = From t In db.Staffs Where t.ClassID = mclassID Select t
Any help would be much appreciated. I've tried ...
I'm working with asp.net 3.5 WebForms and LINQ to Entities.
I created the database with their relationships, but when I go to import the data with LinqToEntities, some reports and have not seen any reports 1 to 1.
Can anyone help me?
I can create them after the reports have imported the tables LinqToEntities?
...
I have a XML file that I need to populate multiple SQL tables, and I was wondering what the best way to do that is. I was thinking dataset, or xslt but I honestly not sure. Here is my generated XML (part of it)
<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
- <!-- Created: 8/3/2010 12:09:15 PM
-->
- <Trip>
- <TripDetail...
I have an IEnumerable that I want to get all the distinct MaterialIDs. I have code that is working but I was wondering if there is a better way possible using LINQ. Here's the code I have:
private IEnumerable<int> GetDistinctMaterialIDs(IEnumerable<TankReading> tankReadings)
{
var distinctMaterialIDs = new List<int>();...