Renaming an Oracle table column.
SQL> desc emp1
Name Null? Type
----------------------------------------- -------- ----------------
EM_NO NOT NULL NUMBER
EMP_NAME VARCHAR2(50)
EMP_DEPT VARCHAR2(50)
EMP_SALARY NUMBER
SQL> alter table emp1 rename column em_no to emp_no;
Table altered.
SQL> desc emp1
Name Null? Type
----------------------------------------- -------- --------------------
EMP_NO NOT NULL NUMBER
EMP_NAME VARCHAR2(50)
EMP_DEPT VARCHAR2(50)
EMP_SALARY NUMBER
