How do I get distinct on a single column in LINQ?

distinct in Linq to get result based on one field of the table (so do not require a whole duplicated records from table). I know writing basic query using distinct as followed: var query = (from r in table1 orderby r. Text select r).

Table of Contents

How to select Distinct values in LINQ?

By Using LINQ we can read distinct values….LINQ: Read Distinct Record from Data Table

public JsonResult getEmpCity()
{
using (CompanyDBEntities dc = new CompanyDBEntities())
{
var query = (from p in dc. Emp_Information.
select p. City). ToList();
return new JsonResult.
{

Why distinct is not working in LINQ?

LINQ Distinct is not that smart when it comes to custom objects. All it does is look at your list and see that it has two different objects (it doesn’t care that they have the same values for the member fields). One workaround is to implement the IEquatable interface as shown here.

How do I remove duplicate values in LINQ query?

To remove duplicates from a C# list using Linq, do the following.

Define a new list. Ours has 7 elements, with “2” and “4” repeating.
Use Distinct().ToList() to make a new list with the distinct elements.
Print out to the console.

How do you use DistinctBy in Linq?

The DistinctBy(IEnumerable, Func, IEqualityComparer) method returns an unordered sequence that contains no duplicate values. If comparer is null , the default equality comparer, Default, is used to compare values.

How does distinct work in Linq?

The Distinct() method works the same way as the DISTINCT directive in SQL. It returns a new sequence containing all the elements from the target sequence that are distinct from each other, as determined by the default equality comparer for the data type of the sequence.

How does distinct work in LINQ?

What is LINQ distinct?

C# Linq Distinct() method removes the duplicate elements from a sequence (list) and returns the distinct elements from a single data source. It comes under the Set operators’ category in LINQ query operators, and the method works the same way as the DISTINCT directive in Structured Query Language (SQL).

What is Linq distinct?

How do I find duplicate records in Linq?

To find the duplicate values only: var duplicates = list. GroupBy(x => x. Key). Where(g => g.

What is TSource in C#?

TSource : element type of the input (source) TResult : element type of the output (result) TKey : element type of a key used for things like grouping. TElement : element type of an intermediate sequence – this is more rarely used, but it appears in some overloads of GroupBy and similar methods.

What is DistinctBy?

DistinctBy is a very simple extension snippet for C# which allows the developer to remove duplicated objects in a collection based on one of its properties (with a lambda expression as a parameter). For example: myCollection.DistinctBy(x => x.Color);

What is select distinct in SQL?

The SQL SELECT DISTINCT Statement The SELECT DISTINCT statement is used to return only distinct (different) values. Inside a table, a column often contains many duplicate values; and sometimes you only want to list the different (distinct) values.

How do we get distinct values using lambda expression?

“how to get distinct values from list in c# using lambda” Code Answer

if (! IsPostBack) {
GridView1. DataSource = GetProducts()
. GroupBy(o => new { o. Make, o. Model })
. Select(o => o. FirstOrDefault());
GridView1. DataBind();
}

What is distinct method?

The Distinct(IEnumerable) method returns an unordered sequence that contains no duplicate values. It uses the default equality comparer, Default, to compare values.

How do you print duplicate characters from a string C#?

How to print duplicate characters in a String using C#? Set maximum value for char. static int maxCHARS = 256; Now display the duplicate characters in the string.

What is difference between single and SingleOrDefault in LINQ?

Use Single() when you are sure that the query must return only one record, and use SingleOrDefault() when a query returns the only element from the sequence, or a default value if the sequence is empty.

What is difference between single and SingleOrDefault?

Single : It returns a single specific element from a collection of elements if element match found. An exception is thrown, if none or more than one match found for that element in the collection. SingleOrDefault: It returns a single specific element from a collection of elements if element match found.

How do you use distinctBy in Linq?

How to use distinct on one column in LINQ?

What is LINQ Distinct Method in C#?

Examples of LINQ Distinct Method using both Method and Query Syntax

How to implement IEqualityComparer?

What is the difference between LINQ, DLINQ and xlinq?

that support LINQ, DLinq, which translates LINQ queries into code that can execute in the context of a database; and XLinq, which handles queries and manipulation of objects in an XML document. So the LINQ framework developers are still concerned with where data resides, but you don’t have to worry about it.

How can a LINQ join select only the first record?

SELECT[tsql-join-query-with-linq].[ProductId],[t1].[OrderId]AS[OrderId],[t1].[OrderNumber]AS[OrderNumber],[tsql-join-query-with-linq].[ProductName],[t1].[Quantity]AS[Quantity],[t1].

FROM[Product]AS[tsql-join-query-with-linq]

LEFT OUTER JOIN[Orders]AS[t1]ON ([tsql-join-query-with-linq].[ProductId]) =[t1].[ProductId]

How can I sort on multiple fields with LINQ?

– It first translates the sorting string into a list of tuples required by the sorting utility; – It then calls the extension method ” MultipleSort ” to sort the list of the students; – At last, it updates the ” Students ” property with the sorted list in the view model, so the sorted student list is visible to the user through MVVM data