Basic Oracle Concepts and Programming Question:

If you have an existing table with existing data rows, and want to add a new column to that table, you can use the ALTER TABLE ... ADD statement to do this. Here is an example script:

SQL> connect HR/globalguideline
Connected.

SQL> CREATE TABLE emp_dept_110
2 AS SELECT * FROM employees WHERE department_id=110;
Table created.

SQL> ALTER TABLE emp_dept_110 ADD (vacation NUMBER);
Table altered.

SQL> SELECT first_name, last_name, vacation
2 FROM emp_dept_110;
<pre>FIRST_NAME LAST_NAME VACATION
-------------------- ------------------------- ----------
Shelley Higgins
William Gietz</pre>
This SQL script added a new column called "vacation" to the "emp_dept_110" table. NULL values were added to this column on all existing data rows.