Table of Contents

Querying Data and Data Sources with code and LINQ

To get started, we recommend you read the LINQ Guide and play around with the Razor Tutorial App

These common (extension) methods can be used on lists from 2sxc data streams (they all inherit from types implementing IEnumerable):

For a full list of all System.Linq methods, check out the methods of IEnumerable

Discover More in the Razor Tutorials

We have an rich series of Razor tutorials. You should really check them out 👍.


Using Statements

As explained in the guide we recommend the following using statements in Razor:

@using System.Linq;
@using Dynlist = System.Collections.Generic.IEnumerable<dynamic>;

Where

Filter a list (IEnumerable) based on a criteria.

Example: Basic filter of a list by string

var items = AsList(Data["Default"]);
items = items.Where(p => p.Name == "Chuck Norris");
// items now contains only items which have "Chuck Norris" as name property

Any

Returns true if any of the elements matches a criteria.

var items = AsList(Data["Default"]);
var containsChuckNorris = items.Any(p => p.Name == "Chuck Norris");
// if containsChuckNorris is true, at least one element has name "Chuck Norris"

Here's another Any - to see if a relationship contains something. It's a bit more complex, because Razor needs to know what it's working with:

// filter - keep only those that have this Category
// note that the compare must run on the EntityId because of object wrapping/unwrapping
    postsToShow = postsToShow
        .Where(p => (p.Categories as List<dynamic>)
            .Any(c => c.EntityId == ListContent.Category[0].EntityId))

OrderBy / OrderByDescending

Order a list (IEnumerable) by a specific field.

var items = AsList(Data["Default"]);
items = items.OrderBy(p => p.Name);
// items are now ordered by property "Name"

First / Last

Get first or last element of the list.

var items = AsList(Data["Default"]);
var first = items.First(); // contains the first element
var last = items.Last(); // contains the last element

Select

Transform list into a new list, selecting only specified field(s).

var items = AsList(Data["Default"]);
var names = items.Select(p => p.Name); // names is a list of all names

Take / Skip

Paging functions: Take only n elements, skip m elements

var items = AsList(Data["Default"]);
items = items.Skip(10).Take(10); // Skips the first 10 elements and select only 10

Count

Count number of elements in a list.

var items = AsList(Data["Default"]);
var count = items.Count(); // contains the number of elements in the list

IndexOf

Find index of a specific element in the list.

@{
    var items = AsList(Data["Default"]);
}
@foreach(var item in items) {
    <h1>Item number @items.IndexOf(item)</h1>
}
Edit this page