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?