摘要： //多字段分组 var query = (from a in db.asgroup a by new { a.F1, a.F2} into gaselect new { key0 = ga.Key, key1 = ga.Key.F1, key2 = ga.Key.F2, Names = ga.Max(a=> a.F3) });foreach (var item in query){ Response.Write("key0:" + item.key0 + "key1:" + item.key1 + "key2:" + item. 阅读全文

摘要： //多表查询 两种方法生成的SQL语句是一模一样 //方法一var query1 = froma in db.as fromb in db.bs.Where(b => b.Id == a.Id)from c in db.cs.Where(c => c.Id== b.Id).DefaultIfEmpty()fromd in db.ds.Where(d => d.Id== c.Id).DefaultIfEmpty()select new{}//方法二var query2 = from a in db.as join b in db.bs on b.Id equals a.Id j 阅读全文