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How use self-join in Linq C#?

by Rhyley Bryan

How use self-join in Linq C#?

This article demonstrates an interesting and very useful concept in LINQ.

  1. Introduction.
  2. Question: What is self-join using LINQ?
  3. Step 1: Create a new web application.
  4. Step 2: Add a new Entity Framework.
  5. Step 3: The complete code of WebForm1.aspx is as in the following:

How write self-join in Linq?

SQL Script

  1. SELECT p.FirstName, q.ManagerName.
  2. FROM Employee p.
  3. INNER JOIN Employee q.
  4. ON p.ManagerID = q.EmpID.

What is group join in LINQ?

What is Linq Group Join? In simple words, we can say that Linq Group Join is used to group the result sets based on a common key. So, the Group Join is basically used to produces hierarchical data structures. Each item from the first data source is paired with a set of correlated items from the second data source.

What is group join?

The group join is useful for producing hierarchical data structures. It pairs each element from the first collection with a set of correlated elements from the second collection. A group join of these two data sources, based on matching Student.Id and Course.

Should I use LINQ to SQL?

LINQ to SQL has many overlaps with other ORM products, but because it is designed and built specifically for .NET and SQL Server, it has many advantages over other ORM products. For example, it takes the advantages of all the LINQ features and it fully supports SQL Server Stored Procedures.

What is the difference between LINQ to SQL and LINQ to objects?

LINQ to SQL is translated to SQL calls and executed on the specified database while LINQ to Objects is executed in the local machine memory . The similarities shared between all aspects of LINQ are the syntax. They all use the same SQL like syntax and share the same groups of standard query operators.

Is there a Java equivalent for LINQ?

There is no equivalent to LINQ for Java. But there is some of the external API which is looks like LINQ such as https://github.com/nicholas22/jpropel-light, https://code.google.com/p/jaque/ lightweight: only 9 public interface/class to learn.