linq commands

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class Default3 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
List x = new List()
{
new emp{ EID=1, NAME="siv", MGR=0, SALARY=5000,DID=1},
new emp{ EID=2, NAME="sankar", MGR=1, SALARY=4000,DID=2},
new emp{ EID=3, NAME="mahadev", MGR=2, SALARY=3000,DID=3},
new emp{ EID=4, NAME="ram", MGR=1, SALARY=2000,DID=5}
};
List y = new List()
{
new dept{ DID=1, DNAME="A"},
new dept{ DID=2, DNAME="B"},
new dept{ DID=3, DNAME="C"},
new dept{ DID=4, DNAME="D"}
};

List z = new List()
{
new salgrade{ LOWSAL=1, HISAL=1000, RANK=1},
new salgrade{ LOWSAL=1001, HISAL=2000, RANK=2},
new salgrade{ LOWSAL=2001, HISAL=3000, RANK=3},
new salgrade{ LOWSAL=3001, HISAL=4000, RANK=4},
new salgrade{ LOWSAL=4001, HISAL=5000, RANK=5}
};
var m = from a in x select a;
var m = from a in x where a.SALARY>=3000 select a;
var m = from a in x where a.SALARY==4000 && a.NAME=="sankar" select a;
var m = from a in x where a.SALARY>=4000 || a.NAME=="sankar" select a;
var m = from a in x where a.NAME!="sankar" select a;
var m = from a in x orderby a.SALARY ascending select a;
var m = from a in x group a by a.DID into b where b.Count() > 1 select new {b.Key,n=b.Count() };
var m = from a in x where a.SALARY < x.Max(b => b.SALARY) select a;
var m = from a in x where a.SALARY > x.Min(b => b.SALARY) select a;
var m = from a in x select new {a.EID,a.NAME,Sumsallary=x.Sum(b=>b.SALARY) };
var m=from a in x
from b in y
where a.DID == b.DID
select new {a.EID,a.NAME,b.DID,b.DNAME};
var m=from a in x
from b in y
from c in z
where a.DID == b.DID && (a.SALARY >= c.LOWSAL && a.SALARY <= c.HISAL) select new {a.EID,a.NAME,a.SALARY,b.DNAME,c.RANK}; var m = from a in x from b in y where 1==1 select new { a.EID, a.NAME, b.DNAME }; var m=from a in x from b in y from c in z where a.DID == b.DID && (a.SALARY >= c.LOWSAL && a.SALARY <= c.HISAL)
select new {a.EID,a.NAME,a.SALARY,b.DNAME,c.RANK};
var m =from a in x
join b in y on a.DID equals b.DID into c
from b in c.DefaultIfEmpty()
select new {a.EID,a.NAME,DNAME=(b==null?null:b.DNAME)};
var m=from a in y
join b in x
on a.DID equals b.DID
into c
from b in c.DefaultIfEmpty()
where b == null
select a;
var m=from a in x
join b in x
on a.MGR equals b.EID
select new { mark = a.NAME + " is working under " + b.NAME };
gv.DataSource = m;
gv.DataBind();
}
class emp
{
public int EID
{
get;
set;
}
public string NAME
{
get;
set;
}
public int MGR
{
get;
set;
}
public decimal SALARY
{
get;
set;
}
public int DID
{
get;
set;
}
}
class dept
{
public int DID
{
get;
set;
}
public string DNAME
{
get;
set;
}
}
class salgrade
{
public decimal LOWSAL
{
get;
set;
}
public decimal HISAL
{
get;
set;
}
public int RANK
{
get;
set;
}
}
}