LInQ的一些查询

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

using LinQ.Models;

namespace LinQ
{
    class Program
    {
        static void Main(string[] args)
        {
            //1.查询东京的学生
            
            List<Student> StuList = Student.GetStudentList();
            //stu 数据范围?,StuList数据源
            //select * from tableName
            var stuQuery = from stu in StuList
                           where stu.studentCity == "东京"
                           select stu;
            foreach (var item in StuList)
            {
                Console.WriteLine("姓名{0},城市{1},性别{2}",item.studentName,item.studentCity,item.studentSex);
            }


            Console.WriteLine("---------查询单个属性---姓名--------------------");

            //查询单个属性
            var stuQueryName = from stu in StuList
                               where stu.studentCity == "东京"
                               select stu.studentName;

            foreach (var item in stuQueryName)
            {
                Console.WriteLine("姓名{0}", item);
            }

            Console.WriteLine("---------查询多个属性--------");
            //查询多个属性
            var temp = from stu in StuList
                       where stu.studentCity == "东京"
                       select new {id=stu.studentID,name=stu.studentName,stu.studentCity };

            foreach (var item in temp)
            {
                Console.WriteLine("id:{0},姓名{1},城市{2}",item.id,item.name,item.studentCity);
            }

            //连接查询
            Console.WriteLine("-------连接查询-------");
            DemoJoinOn();

            Console.ReadKey();
        }
        public static void DemoJoinOn()
        {
            
            var temp = from stu in Student.GetStudentList()
                       join teach in Teacher.GetTeacherList()
                       on stu.teacherID equals teach.teacherID
                       select new { stu.studentName, teach.teacherName };

            foreach (var item in temp)
            {
                Console.WriteLine("学生姓名:{0},老师姓名{1}",item.studentName,item.teacherName);
            }
        }
    }
}

 

posted on 2017-10-31 11:49  CCCCCC1129  阅读(105)  评论(0编辑  收藏  举报

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