求帮忙把sql 转 一下lambda，lambda不知道怎么写出来，跪求

表名：user
字段：Id(主键)
      Code(编号) 
      RecId(外键,关联Id)  

select Code,(select COUNT(*) from user where RecId = u.Id) as RecCount from user as u;

user.GroupJoin(user, x => x.Id, x => x.RecId, (x, y) => new {x, y}).Select(x => new { RecCount = x.y.Count(), x.x.Code })