Veja o exmeplo:
SQL> SELECT * FROM EMP WHERE EMPNO='&X.1';
Enter value for x: 752
old 1: SELECT * FROM EMP WHERE EMPNO='&X.1'
new 1: SELECT * FROM EMP WHERE EMPNO='7521'
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
1 row selected.
SQL>