In earlier versions of EF Core, performing a LEFT JOIN in LINQ required a complex combination of SelectMany, GroupJoin, and DefaultIfEmpty.
With .NET 10, a new built-in LeftJoin method simplifies this process. It allows developers to write cleaner and more intuitive LINQ queries, and EF Core fully supports it in database queries.
Example:
var studentDepartments = context.Students
.LeftJoin(
inner: context.Departments,
outerKeySelector: student => student.DepartmentID,
innerKeySelector: department => department.ID,
resultSelector: (student, department) => new
{
FirstName = student.FirstName,
LastName = student.LastName,
Department = department.Name ?? "[NONE]"
});
Cheers
Samitha