Cast String to int and use in Where clause

Question

How to convert string field and use for Where clause.Am getting exception like this please help to find the wrong thing.

select * from student 
where (cast (         


        

Answer 1

Compare only when is numeric

select * from student 
where 
  (
  case when ISNUMERIC( linerevnum ) 
  then cast (linerevnum as int)
  else null
  end  ) = 1

or simple:

select * from student 
linerevnum = '1'