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(109) 评论(0) 编辑 收藏 举报