¿Cómo utilizar Union all en LINQ to SQL?

How to use Union all in LINQ to SQL?

How to use union all in LINQ TO SQL. I have use the following code for union, then how to use this for union all? Concat is the LINQ equivalent of UNION ALL in SQL. I’ve set up a simple example in LINQPad to demonstrate how to use Union and Concat. If you don’t have LINQPad, get it.

The UNION operator is used to combine the result-set of two or more SELECT statements. The UNION operator selects only distinct values by default. To allow duplicate values, use UNION ALL: Note: The column names in the result-set are usually equal to the column names in the first SELECT statement.

The LINQ Union () Method like other Set Operators such as Distinct, Expect, Intersect is also worked in a different manner when working with complex types such as Product, Employee, Student, etc. Let us understand this with an example. Create a class file with the name Student.cs and then copy and paste the following code in it.

Now run the application and it will give us the following output. As you can see it displays the country “UK” twice. This is because the default comparer that is being used by the LINQ Union method is case-insensitive.

Union and Concat behave the same since Union can not detect duplicates without a custom IEqualityComparer . It’s just looking if both are the same reference. Thanks for contributing an answer to Stack Overflow!

It requires at least two collections to perform the merge operation, but that merged collection holds only the distinct elements from both the collections. For better understanding, we will use an example. In above result you can see the elements are unique because union removed the repeated/duplicate elements from both collections/ list.

In LINQ to SQL, the Union operator is defined for multisets as the unordered concatenation of the multisets (effectively the result of the UNION ALL clause in SQL). For more info and examples, see Queryable.Union.