试试这样，

 选择 MAX（EmpNumber ）来自表1 

欲了解更多信息，请参阅此处，

http://www.w3schools.com/sql/sql_func_max.asp [ ^ ]

>

  var  maxValue = _enumerable.Max（item =item.EmpNumber）; 

Srno EmpNumber
1 1
1 2
1 3
1 4
2 1
2 2
2 3
2 4
2 5
2 6
2 7
2 8
2 9
2 10
2 11
2 12
2 13
2 14
2 15
2 16
2 17
2 18
2 19
2 20
3 1
3 2
3 3
3 4
3 5

Try like this,

select MAX(EmpNumber) from Table1

For more info you may refer here,
http://www.w3schools.com/sql/sql_func_max.asp[^]

var maxValue = _enumerable.Max(item =》 item.EmpNumber);