Issue

This Content is from Stack Overflow. Question asked by userSteve

When I look for examples of LINQ statements, often the select result doesn’t just return the object or properties directly but as a new anonymous type.
Why is this?

var teenStudents = from s in studentList
where s.age > 12 && s.age < 20
select new { s };

why not just select s;

Solution

It really depends on the use case.

If the entire entity data is required, no further projection is required.

var teenStudents = from s in studentList
where s.age > 12 && s.age < 20
select s;

Some scenarios where we project the data into a new anonymous object is

When we need to select only specific properties from say a large entity having 20 columns. It makes the querying efficient
When we do not have an entity object to project the output to and you don’t intend to create one

It could be something like

var teenStudents = from s in studentList
where s.age > 12 && s.age < 20
select new {Name= s.name, Age = s.age } ;

If you have another DTO class which you can project to, you can do

var teenStudents = from s in studentList
where s.age > 12 && s.age < 20
select new StudentDTO {Name= s.name, Age = s.age } ;

This Question was asked in StackOverflow by userSteve and Answered by WisdomSeeker It is licensed under the terms of CC BY-SA 2.5. - CC BY-SA 3.0. - CC BY-SA 4.0.