Question

Rahul forgot to add a column in the existing table. Which one of the following SQL commands can he use to add the desired column in the table?

• A. INSERT
• B. UPDATE
• C. MODIFY
• D. ALTER

Hint:

Use ALTER to add, delete, or modify columns in an existing SQL table.

Answer 1

The Correct Option is D

In SQL, the ALTER command is used to make changes to the structure of an existing table.
This includes operations such as adding, deleting, or modifying columns.
To add a new column, the syntax is: ALTER TABLE table_name ADD column_name datatype.
- The INSERT command is used to add new rows (records), not columns.
- The UPDATE command is used to change data in existing rows.
- The MODIFY keyword is not valid in standard SQL for altering table structure; it is used in some dialects only for altering column properties, not for adding new columns.
Thus, to add a column, the correct and standard SQL command is ALTER.