LINQ中select操作符(四)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LinqOfSelectOperation
{
    public class Students
    {
        public string ID { get; set; }
        public string Name { get; set; }
        public string ClassName { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            //使用集合初始化器给集合赋值
            List<Students> studentList = new List<Students>
            {
                new Students(){ID="0001", Name="张三", ClassName="01"},
                new Students(){ID="0002", Name="李四", ClassName="02"},
                new Students(){ID="0003", Name="王五", ClassName="01"}
            };

            //查询语法：全部返回
            var query1 = (from p in studentList where p.Name.StartsWith("张") select p);
            //查询语法：返回匿名类
            var query2 = (from p in studentList where p.Name.StartsWith("张") select new { p.ID, p.Name });
            //查询语法：返回匿名类，属性重新命名
            var query3 = (from p in studentList where p.Name.StartsWith("张") select new { newID = p.ID, newName = p.Name });

            //查询方法: 全部返回, 可以省略最后的select延迟加载
            var query4 = studentList.Where(p => p.Name.StartsWith("张"));
            //查询方法: 返回匿名类
            var query5 = studentList.Where(p => p.Name.StartsWith("张")).Select(p => new { p.ID, p.Name });
            //查询语法：返回匿名类，属性重新命名
            var query6 = studentList.Where(p => p.Name.StartsWith("张")).Select(p => new { newID = p.ID, newName = p.Name });
        }
    }
}