Linq的简单应用_01

    class Program
    {
        static void Main(string[] args)
        {
            //Linq to Sql
            DataContext dc = new DataContext(new SqlConnection("server=.;database=SuperMarket;uid=sa;pwd=12345"));
            var ttt =from b in dc.GetTable<GoodsTypes>() group b by b.UpId into D11 select new {
                id = D11.Key,
                data = D11
            };
            foreach (var item in ttt)
            {
                Console.WriteLine("根据:"+item.id+"分组");
                foreach (var item1 in item.data)
                {
                    Console.WriteLine("	"+item1.TypeName);
                }
            }
            var resutldc = from b in dc.GetTable<GoodsTypes>() select b;
            foreach (var item in resutldc)
            {
                Console.WriteLine(item.TypeName);
            }
            dc.Dispose();
            //Linq to Xml
            Book[] books = {
                               new Book{Name="小白",Year=2006,Title="汇编语言"}, 
                               new Book{Name="小菜",Year=2006,Title="OOD"}, 
                               new Book{Name="小静",Year=2002,Title="你不知道的C#"}, 
                           
                           };
            //需求:查询2006年的书籍,并生成Xml
            var d = new XElement("Books",
                from b in books
                where b.Year == 2006
                select new XElement("book",
                    new XAttribute("Title", b.Title),
                    new XElement("year", b.Year)));
            Console.WriteLine(d);
            //Linq To Objects
            string[] words = { "hello", "wonderful", "linq", "beautiful", "world" };

            var result = from b in words
                         orderby
                             b ascending
                         group b by b.Length into groups
                         orderby groups.Key descending
                         select new
                         {
                             lenth = groups.Key,
                             data = groups
                         };
            foreach (var item in result)
            {
                Console.WriteLine("world length:" + item.lenth);
                foreach (var item1 in item.data)
                {
                    Console.WriteLine("	" + item1);
                }
            }

            Console.Read();
        }

    }
    [Table(Name = "GoodsTypes")]
    class GoodsTypes
    {
        [Column(IsPrimaryKey=true)]
        public int TypeId { get; set; }
        [Column(Name = "TypeName")]
        public string TypeName { get; set; }
        [Column]
        public string Memo { get; set; }
        [Column]
        public int UpId { get; set; }
    }
    class Book
    {
        public string Name { get; set; }
        public string Title { get; set; }
        public int Year { get; set; }
    }