How to Add and Remove Columns in SQL Server: A Beginner’s Guide

In SQL Server, you can use the ALTER TABLE statement to add or remove columns from an existing table. Adding a column to a table allows you to store additional information, while removing a column can help simplify the table structure and improve performance.

To add or remove a column from an existing table in SQL Server, you can use the ALTER TABLE statement.

To add a column to an existing table, you can use the following syntax:

ALTER TABLE table_name 
ADD column_name datatype;

For example, to add a column named “Email” of type VARCHAR(50) to a table named “Customers”, you can use the following command:

ALTER TABLE Customers
ADD Email VARCHAR(50);

To remove a column from an existing table, you can use the following syntax:

ALTER TABLE table_name
DROP COLUMN column_name;

For example, to remove a column named “Phone” from the “Customers” table, you can use the following command:

ALTER TABLE Customers
DROP COLUMN Phone;

It’s important to note that adding or removing a column from an existing table can affect the data already stored in the table. Therefore, it’s recommended to create a backup of the table before making any changes.