Question

When adding a column to an existing table, the ____________________ clause must be used with the ALTER TABLE command.​

Answer 1

To add a column to an existing table in SQL, the ADD COLUMN clause is used with the ALTER TABLE command. This allows you to specify the new column's name and data type and modify the table's structure accordingly.

Step-by-step explanation:

When adding a column to an existing table, the ADD COLUMN clause must be used with the ALTER TABLE command. For example, if you want to add a column named 'email' of type VARCHAR to a table called 'users', the SQL command would look like this:

ALTER TABLE users ADD COLUMN email VARCHAR (255);

This command will modify the structure of the 'users' table to include a new column for storing email addresses. It is important to note that the ALTER TABLE command and its clauses can vary slightly between different SQL database management systems, such as MySQL, PostgreSQL, and SQLite.