返回完整结果linq分组查询

Question

我想分组，并仍然检索表中的所有数据。我对Linq还很陌生，似乎无法告诉我做错了什么。我不仅想对结果进行分组，而且还想检索表格中的所有列。这可能吗？

(from r in db.Form 
    orderby r.CreatedDate descending 
    group r by r.Record into myGroup 
    where myGroup.Count() > 0 
    where (r.CreatedDate > lastmonth) 
    where r.Name == "Test Name" 
    select new { r, myGroup.Key, Count = myGroup.Count() } 
    ) 

一些如何“r”失去其上下文或自从我分组“r”它已被替换。不确定。

Answer 1

您需要将任务分成两个步骤来完成你想要的。

组数据

var groupedData = db.Form.Where(item=>item.CreatedDate > lastMonth && item.Name == "Test Name") 
        .OrderByDescending(item=>item.item.CreatedDate) 
        .GroupBy(item=>item.Record) 
        .Select(group => new {Groups = group, Key = group.Key, Count = group.Count()}) 
        .Where(item => item.Groups.Any()); 

从分组数据选择Form元素

var formElements = groupedData.SelectMany(g => g.Groups).ToList(); 

Answer 2

既然你个人的记录过滤，您应该分组，而不是前后进行筛选：

(
    from r in db.Form 
    where r.CreatedDate > lastMonth) 
    where r.Name == "Test Name" 
    orderby r.CreatedDate descending 
    group r by r.Record into myGroup 
    where myGroup.Count() > 0 
    select new { Groups = myGroup, myGroup.Key, Count = myGroup.Count() } 
) 
// Groups is a collection of db.Form instances