How to group by the selected columns\properties of new class in linq?

Question

var query = context.headerItems
            .Where(header => header.headerColumn1 != false)
            .Where(item => item.itemColumn1 != null)
            .Select(header => new {
                //Only columns from header table in here
            })
            .ToList()
            .Select(header => new context.header{
                //Only columns from header table in here
            });
return query.ToList();

headerItems are join between header and items .

How do I group by all the selected columns\\properties of header?

Answer 1

如果要对所有列进行分组，而无需计算计数或总数，则可以简单地使用distinct ，它也可以得出相同的结果。