What are LINQ group queries and how do I use them?

What are LINQ group queries and how do I use them?

LINQ group queries allow you to group data based on a specific key. You can use the group by clause in your query.

Can you show me an example of a group query in C#?

Sure! Here's a simple example:

var groupedData = from student in students
                 group student by student.Class into studentGroup
                 select new {
                     Class = studentGroup.Key,
                     Students = studentGroup.ToList()
                 };

What if I want to group by multiple keys?

You can group by multiple keys by using an anonymous type. For example:

var groupedData = from student in students
                 group student by new { student.Class, student.Age } into studentGroup
                 select new {
                     Class = studentGroup.Key.Class,
                     Age = studentGroup.Key.Age,
                     Students = studentGroup.ToList()
                 };

Are there any performance considerations I should be aware of?

Yes, grouping can be resource-intensive, especially with large datasets. It's important to optimize your queries and consider indexing.