using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace First_exam
{
class Student
{
/// <summary>
///学生姓名的字段和属性
/// </summary>
private string _Name;
public string Name
{
get { return this._Name; }
}
private string _Xingbie;
/// <summary>
/// 学生性别的字段和属性
/// </summary>
public string Xingbie
{
get { return this._Xingbie; }
}
/// <summary>
/// 学生年龄的字段和属性
/// </summary>
private uint _Age;
public uint Age
{
get { return this._Age; }
}
/// <summary>
/// 学生成绩的字段和属性
/// </summary>
private List<LessonScore> _Scores;
public List<LessonScore> Scores
{
get { return this._Scores; }
}
/// <summary>
/// 构造函数，传入学生姓名，性别，年龄，成绩
/// </summary>
public Student(string name, string xb, uint age, List<LessonScore> scrs)
{
this._Name = name;
this._Xingbie = xb;
this._Age = age;
this._Scores = scrs;
}
public Student(string name, string xb, uint age)
{
this._Name = name;
this._Xingbie = xb;
this._Age = age;
this._Scores = null;
}
public override string ToString()
{
string str;
str = string.Format("{0}--{1}--{2}",this._Name, this._Age,this._Xingbie);
return str;
}
}
class LessonScore
{
/// <summary>
/// 课程成绩的字段和属性
/// </summary>
private float _Score;
public float Score
{
get { return this._Score; }
}
/// <summary>
/// 课程名称的字段和属性
/// </summary>
private string _Lessson;
public string Lesson
{
get { return this._Lessson; }
}
/// <summary>
/// 构造函数
/// </summary>
public LessonScore(string les, float scr)
{
this._Lessson = les;
this._Score = scr;
}
public override string ToString()
{
string str;
str = string.Format("{0}----{1}分", this._Lessson,this._Score);
return str;
}
}
class Program
{
static void Main(string[] args)
{
Student[] arr =
{
new Student("张氏那","男",20),
new Student("李四","男",23),
new Student("李霞","女",23),
new Student("王妈妈","女",25),
new Student("郭明","男",22),
new Student("欧阳夏","女",24),
new Student("王丹","女",20),
new Student("张宝","男",25),
};
var query =
from val in arr
select val;
foreach (Student item in query)
{
Console.WriteLine(item);
}
Console.WriteLine();
var query2 =
from val in arr
select val.Name;
foreach(string item in query2)
{
Console.Write("{0}, ",item);
}
Console.WriteLine();
Console.WriteLine();
var query3 =
from val in arr
select val.Name.Length;
foreach (int item in query3)
{
Console.Write("{0}, ", item);
}
Console.WriteLine();
Console.WriteLine();
var query4 =
from val in arr
select new { val.Name, val.Age, NameLen = val.Name.Length};
foreach(var item2 in query4)
{
Console.WriteLine(item2);
}
Console.WriteLine();
int[] ary = { 9,54,32,1,67,43,0,9,7,4,9,2,23,66,61};
var query5 =
from val in ary
orderby val
select val;
foreach(var item in query5)
{
Console.Write("{0} ",item);
}
Console.WriteLine();
Console.WriteLine();
var query6 =
from val in ary
orderby val descending
select val;
foreach (var item in query6)
{
Console.Write("{0} ", item);
}
Console.WriteLine();
Console.WriteLine();
var query7 =
from val in arr
orderby val.Name.Length ascending, val.Age descending
select val;
foreach(var item in query7)
{
Console.WriteLine(item);
}
Console.WriteLine();
var query8 =
from val in arr
group val by val.Xingbie;
foreach(var grp in query8)
{
Console.WriteLine(grp.Key);
foreach(var st in grp)
{
Console.WriteLine("\t{0}",st);
}
}
Console.WriteLine();
var query9 =
from val in arr
group val by val.Age into stgrp
orderby stgrp.Key descending
select stgrp;
foreach(var st in query9)
{
Console.WriteLine("{0}岁的学生：",st.Key);
foreach(var stu in st)
{
Console.WriteLine("\t{0}",stu);
}
}
Console.WriteLine();
Console.WriteLine("**************************************************************************");
Console.WriteLine();
/*
*from子句的复合查询
*/
Student[] stAry = {
new Student("张氏那","男",20,
new List<LessonScore>{
new LessonScore("语文",80.5f),
new LessonScore("数学",90f),
new LessonScore("英语",89f)
}),
new Student("李四","男",23,
new List<LessonScore>{
new LessonScore("语文",86.5f),
new LessonScore("数学",97f),
new LessonScore("英语",95f)
}),
new Student("李霞","女",23,
new List<LessonScore>{
new LessonScore("语文",76f),
new LessonScore("数学",85f),
new LessonScore("英语",79f)
}),
new Student("王妈妈","女",25,
new List<LessonScore>{
new LessonScore("语文",85f),
new LessonScore("数学",87f),
new LessonScore("英语",79f)
}),
new Student("郭明","男",22,
new List<LessonScore>{
new LessonScore("语文",69f),
new LessonScore("数学",72f),
new LessonScore("英语",83f)
}),
new Student("欧阳夏","女",24,
new List<LessonScore>{
new LessonScore("语文",85f),
new LessonScore("数学",85f),
new LessonScore("英语",79f)
}),
new Student("王丹","女",20,
new List<LessonScore>{
new LessonScore("语文",73f),
new LessonScore("数学",77f),
new LessonScore("英语",80f)
}),
new Student("张宝","男",25,
new List<LessonScore>{
new LessonScore("语文",88f),
new LessonScore("数学",89f),
new LessonScore("英语",94f)
}),
};
var query10 =
from st in stAry
from scr in st.Scores
where scr.Score > 80
group new { st.Name, scr } by st.Name;
foreach(var grp in query10)
{
Console.WriteLine(grp.Key);
foreach(var item in grp)
{
Console.WriteLine("\t{0}",item);
}
}
Console.WriteLine();
Console.WriteLine("**************************************************************************");
Console.WriteLine();
int[] intarry1 = { 5,10,15,20,25,50,30,33,100};
int[] intarry2 = { 10,20,30,40,50,60,70,80,90,100};
var query11 =
from val1 in intarry1
from val2 in intarry2
where val2 % val1 == 0
group val2 by val1;
foreach(var grp in query11)
{
Console.Write("{0}: ",grp.Key);
foreach(var val in grp)
{
Console.Write("{0} ",val);
}
Console.WriteLine();
}
Console.WriteLine();
Console.WriteLine("*********************join*****************************************");
Console.WriteLine();
Console.WriteLine("**********内部联接**************************");
int[] intarray1 = { 5,15,25,30,33,40};
int[] intarray2 = { 10,20,30,40,50,60,70,80,90,100};
var query12 =
from val1 in intarray1
join val2 in intarray2 on val1 % 5 equals val2 % 15
select new { VAL1 = val1,VAL2 = val2};
foreach(var val in query12)
{
Console.WriteLine(val);
}
Console.WriteLine();
Console.WriteLine("**********分组联接**************************");
var query13 =
from val1 in intarray1
join val2 in intarray2 on val1 % 5 equals val2 % 15 into grpName
select new { VAL1 = val1, VAL2 = grpName};
foreach(var val in query13)
{
Console.Write("{0}: ",val.VAL1);
foreach(var obj in val.VAL2)
{
Console.Write("{0} ",obj);
}
Console.WriteLine();
}
Console.WriteLine();
Console.WriteLine("**********左外部联接**************************");
var query14 =
from val1 in intarray1
join val2 in intarray2 on val1 % 5 equals val2 % 15 into grpName
from grp in grpName.DefaultIfEmpty()
select new { VAL1 = val1 , VAL2 = grp};
foreach(var val in query14)
{
Console.WriteLine(val);
}
}
}
}
