How do I join two tables in LINQ?

Basically in SQL, we use the INNER JOIN keyword to make relationship between both tables.

  1. SELECT [t1].[OrderId], [t1].[OrderNumber], [tsql-join-query-with-linq].[ProductName], [t1].[Quantity], [t1].[TotalAmount], [t1].[OrderDate]
  2. FROM [Product] AS [tsql-join-query-with-linq]
  3. INNER JOIN [Orders] AS [t1]

Do join in LINQ?

In a LINQ query expression, join operations are performed on object collections. Object collections cannot be “joined” in exactly the same way as two relational tables. In LINQ, explicit join clauses are only required when two source sequences are not tied by any relationship.

How use inner join in LINQ?

In LINQ, an inner join is used to serve a result which contains only those elements from the first data source that appears only one time in the second data source. And if an element of the first data source does not have matching elements, then it will not appear in the result data set.

How use inner join in C#?

In relational database terms, an inner join produces a result set in which each element of the first collection appears one time for every matching element in the second collection. If an element in the first collection has no matching elements, it does not appear in the result set.

How do you write a LINQ query?

This query returns two groups based on the first letter of the word. // Query #1. List numbers = new List() { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; // The query variable can also be implicitly typed by using var IEnumerable filteringQuery = from num in numbers where num < 3 || num > 7 select num; // Query #2.

Can I join a table to a list using LINQ?

You probably found out that you can’t join an Entity Framework LINQ query with a local list of entity objects, because it can’t be translated into SQL. I would preselect the database data on the account numbers only and then join in memory.

What is join in C#?

In C#, Join() is a string method. This method is used to concatenates the members of a collection or the elements of the specified array, using the specified separator between each member or element.

What is group join in LINQ?

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 meant by LINQ in C#?

Language-Integrated Query (LINQ) is the name for a set of technologies based on the integration of query capabilities directly into the C# language.

What are the disadvantages of LINQ?


  • It is hard to write a LINQ provider.
  • Lambdas and extension methods are my hammers and all problems are nails.
  • No clear outline for Tiers.
  • LINQ is not good to write complex queries like SQL Server.
  • There is no good way of view permissions.
  • Deferred execution and streaming are poorly understood.

Why LINQ is used?

LINQ in C# is used to work with data access from sources such as objects, data sets, SQL Server, and XML. LINQ is a data querying API with SQL like query syntaxes. LINQ provides functions to query cached data from all kinds of data sources. The data source could be a collection of objects, database or XML files.