Table Creation and Management

Identify the table name and structure

Commands used to create or modify database tables are called data definition language(DDL commands

A Database Object is a defined self contained structure also called database tables

Creating Tables	Description
CREATE TABLE	Creates a new table in the database. The user names the columns and identifies the type of data to be stored. To view a table, use the SQL*PLUS command DESCRIBE.
Modifying Tables
ALTER TABLE . . . ADD	Adds a column to a table.
ALTER TABLE . . . MODIFY	Changes a column size, datatype, or default value.
ALTER TABLE . . . DROP COLUMN	Deletes one column from a table
ALTER TABLE . . . SET UNUSED or SET UNUSED COLUMN	Marks a column for deletion at a latertime.

Create a new table with the CREATE TABLE command

Use a subquery to create a new table

Add a column to an existing table

Modify the definition of a column in an existing table

Delete a column from an existing table

Mark a column as unused and then delete it later

Rename a table

Truncate a table

Drop a table