Lesson 25: ALTER TABLE in PostgreSQL – Add New Columns to Existing Tables
In this lesson, you will learn how to use the ALTER TABLE command in PostgreSQL to add new columns to an existing table without deleting or recreating it. This is very useful when your database structure needs to grow or change over time.
You will see how to add a single column or multiple columns, set data types, and apply rules like DEFAULT values or NOT NULL constraints. This helps you update your table safely while keeping your existing data.
By the end of this lesson, you will understand how to modify tables step by step and manage real-world database changes easily.