How to get first record in each group using LINQ?

LINQ select first row in each group

  1. select * from customer c1.
  2. where Total =
  3. (
  4. select max(total) from customer c2.
  5. where c1. customer=c2. customer.
  6. group by c2. customer.
  7. )
  8. order by total.

How do you select the top 1 row in LINQ?

“linq query select top 1 c#” Code Answer

  1. imageName = (from soh in db. tblProductImages.
  2. where soh. product_id == e. ProductId.
  3. select soh. image_name). FirstOrDefault()

Which function is used to get first record in a LINQ collection?

Use First() when you are sure that a query must return a record, and use FirstOrDefault() when you are not sure whether it will return a record or not.

How do I get my first record in LINQ?

how to take first 10 record using LINQ?

  1. var query = from a in context. Advertisements where a. idPartner == partnerid select a;
  2. count = query. Count();
  3. if (count > 10)
  4. return (query. Skip(startIndex). Take(10). ToList());
  5. else.
  6. return query. ToList();

How do you select top record in Linq?

Linq Query To Select Top 5 Records

  1. var list = (from t in ctn.Items.
  2. where t.DeliverySelection == true && t.Delivery.SentForDelivery == null.
  3. orderby t.Delivery.SubmissionDate.
  4. select t). Take(5);

How do you use take and skip in Linq?

Take and Skip Operator In LINQ to SQL

  1. Create a Data Context Class. I create a data context class that has tables or a stored procedure.
  2. Create UI Design. I use a GridView to show employee data.
  3. Take Operator.
  4. Skip Operator.

What is difference between first and FirstOrDefault in Linq?

Difference Between First() And FirstOrDefault() The major difference between First and FirstOrDefault is that First() will throw an exception if there is no result data for the supplied criteria whereas FirstOrDefault() will return the default value (null) if there is no result data.

What is FirstOrDefault Linq?

Use the FirstorDefault() method to return the first element of a sequence or a default value if element isn’t there.

What is meant by Linq in C#?

LINQ stands for Language Integrated Query. LINQ is a data querying API that provides querying capabilities to . NET languages with a syntax similar to a SQL. LINQ in C# is used to work with data access from sources such as objects, data sets, SQL Server, and XML. LINQ stands for Language Integrated Query.

How do I sort in LINQ?

There are 5 different types of sorting operators are available in LINQ:

  1. OrderBy.
  2. OrderByDescending.
  3. ThenBy.
  4. ThenByDescending.
  5. Reverse.

What is take in LINQ?

The Take operator is used to return a given number of rows from a database table and the Skip operator skips over a specifed number of rows in a database table. In this article I am going to explain the Take and Skip operators in LINQ to SQL.

How to get the first record of a group in LINQ?

Maybe the sorting of the date should be done in a separate function, not sure. This will group all the elements by CardId, then order the elements of each group by DateTimeStamp (descending), then pare down each group to only contain the first element.

How to select the first and last values in LINQ?

I have the following code: This seems inefficient to me as I select the entire date range values initially. I can’t seem to find a way to put first and last into the select command. Surely there must be a way to do this?

When to use first or firstordefault in LINQ?

Note: If you’re using LINQ-to-Entities you will get a runtime exception if you use First () instead of FirstOrDefault () here as the former can only be used as a final query operation. First of all, I wouldn’t use a multi-dimensional array.

How to sort by Stack in C #-LINQ?

For those wondering how to do this for groups that are not necessarily sorted correctly, here’s an expansion of this answer that uses method syntax to customize the sort order of each group and hence get the desired record from each.