與SQL命令中的Where作用相似芬首，起到過濾作用畴博。
一個(gè)員工安排到一輛車上瓢捉，一輛車可以有很多員工频丘，車牌號(hào)和員工號(hào)是一對(duì)多的關(guān)系。
員工類

public class Employee
{
       /// <summary>
       /// 車牌號(hào)
       /// </summary>
       public int CarNo { get; set; }

       /// <summary>
       /// 員工號(hào)
       /// </summary>
       public string EmployeeNo { get; set; }

       /// <summary>
       /// 描述
       /// </summary>
       public string Description { get; set; }

       /// <summary>
       /// 年齡
       /// </summary>
       public int Age { get; set; }
}

獲取員工數(shù)據(jù)方法

public static List<Employee> GetList()
{
        return new List<Employee>()
        {
                 new Employee(){ CarNo=1,EmployeeNo="NO-1",Description ="廣州分公司",Age=21},
                 new Employee(){ CarNo=2,EmployeeNo="NO-2",Description ="惠州分公司",Age=30},
                 new Employee(){ CarNo=3,EmployeeNo="NO-3",Description ="東莞分公司",Age=27},
                 new Employee(){ CarNo=4,EmployeeNo="NO-4",Description ="廣州分公司",Age=28},
                 new Employee(){ CarNo=3,EmployeeNo="NO-4",Description ="東莞分公司",Age=52},
                 new Employee(){ CarNo=1,EmployeeNo="NO-5",Description ="深圳分公司",Age=18},
                 new Employee(){ CarNo=1,EmployeeNo="NO-6",Description ="中山分公司",Age=21},
                 new Employee(){ CarNo=2,EmployeeNo="NO-7",Description ="廣州分公司",Age=31},
                 new Employee(){ CarNo=5,EmployeeNo="NO-8",Description ="佛山分公司",Age=19},
                 new Employee(){ CarNo=6,EmployeeNo="NO-9",Description ="深圳分公司",Age=20}
        };
}

獲取年齡大于30歲的所有員工信息

var employeeList = Employee.GetList();
var list = employeeList.Where(x => x.Age > 30);
StringBuilder sb = new StringBuilder();
foreach (var item in list)
{
      sb.AppendFormat("員工號(hào){0}泡态，描述：{1}搂漠，年齡：{2}<br/> ", item.EmployeeNo, item.Description, item.Age);
}

輸出結(jié)果：

員工號(hào)NO-4，描述：東莞分公司某弦，年齡：52
員工號(hào)NO-7桐汤，描述：廣州分公司而克，年齡：31

獲取年齡大于20歲并且坐1號(hào)車的所有員工信息

var employeeList = Employee.GetList();
var list = employeeList.Where(x => x.Age > 20 && x.CarNo == 1);
StringBuilder sb = new StringBuilder();
foreach (var item in list)
{
      sb.AppendFormat("員工號(hào){0}，描述：{1}怔毛，年齡：{2}<br/> ", item.EmployeeNo, item.Description, item.Age);
}

或者

var employeeList = Employee.GetList();
var list = employeeList.Where(x => x.Age > 20).Where(x => x.CarNo == 1);
StringBuilder sb = new StringBuilder();
foreach (var item in list)
{
      sb.AppendFormat("員工號(hào){0}员萍，描述：{1}，年齡：{2}<br/> ", item.EmployeeNo, item.Description, item.Age);
}

輸出結(jié)果：

員工號(hào)NO-1拣度，描述：廣州分公司碎绎，年齡：21
員工號(hào)NO-6，描述：中山分公司蜡娶，年齡：21