SQL Query Add new Column Existing Table

The SQL ALTER TABLE statement allows you to rename an existing table. It can also be used to add, modify, or drop a column from an existing table.

SQL ALTER TABLE - Renaming a table

To rename a table, the SQL ALTER TABLE syntax is:

ALTER TABLE table_name
  RENAME TO new_table_name;

For example:

ALTER TABLE suppliers
  RENAME TO vendors;

This will rename the suppliers table to vendors.

SQL ALTER TABLE - Adding column(s) to a table

Syntax #1
To add a column to an existing table, the SQL ALTER TABLE syntax is:

ALTER TABLE table_name
  ADD column_name column-definition;

For example:

ALTER TABLE supplier
  ADD supplier_name varchar2(50);

This will add a column called supplier_name to the supplier table.