Where: How to Search for Various Conditions

This query presents the operator with a choice of how to find data. After selecting a search field, and entering a value, a decode is used to generate SQL code. The New_Value clause sets that equal to &xWhere, and it is used with the 'Where' clause.

(I have tried incorporating it directly into the Where with no luck.)

Prompt
Prompt                +------------------------------------------+
Accept Choice Prompt '| Search by 1-EmpNo 2-EName : '
Accept Value  Prompt '| Please enter Value        : '
Prompt                +------------------------------------------+

Set Term Off
Column WhereClause New_Value xWhere
Select         Decode(&Choice, 1, 'EmpNo=&Value',
                               2, 'EName='||Upper('''&Value''')
                     )
               As 
       WhereClause
  From Dual;
Set Term On

Select EmpNo, EName, Job, HireDate, DeptNo
  From Emp
 Where &xWhere;