ALTER TABLE - Delete a Column in Oracle

Q

How To Delete a Column in an Existing Table in Oracle?

✍: FYIcenter.com

A

If you have an existing column in a table and you need that column any more, you can delete it with ALTER TABLE ... DROP COLUMN statement. Here is an example SQL script:

SQL> CREATE TABLE emp_dept_90 
  2  AS SELECT * FROM employees WHERE department_id=90;
Table created.

SQL> SELECT last_name FROM emp_dept_90;
LAST_NAME                
-------------------------
King                     
Kochhar                  
De Haan                  

SQL> ALTER TABLE emp_dept_90 DROP COLUMN last_name;
Table altered.

SQL> SELECT last_name FROM emp_dept_90;
ERROR at line 1:
ORA-00904: "LAST_NAME": invalid identifier

As you can see the column "last_name" is gone.

⇒ DROP TABLE Statement in Oracle

⇐ ALTER TABLE - Add a New Column in Oracle

⇑ Understanding SQL DDL Statements for Oracle

⇑⇑ Oracle Database Tutorials

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