Question

Which of the following functions are not performed by “ALTER” clause?

(a) Change the name of the table

(b) Change the name of the column

(c) Drop a column

(d) All of the mentioned

The question was posed to me in examination.

My query is from Populating & Modifying Tables topic in section Using SQL to Manage Data of MySQL

Answer 1

The correct answer is:

(d) All of the mentioned

Explanation: The ALTER clause in SQL is used to modify an existing database structure, such as adding, deleting, or modifying columns in a table. Here's a breakdown of the options:

• (a) Change the name of the table: The ALTER clause can indeed be used to rename a table using the RENAME TO command (e.g., ALTER TABLE old_table_name RENAME TO new_table_name;).

• (b) Change the name of the column: The ALTER clause can also be used to rename a column using the CHANGE COLUMN command (e.g., ALTER TABLE table_name CHANGE old_column_name new_column_name column_definition;).

• (c) Drop a column: The ALTER clause can also drop a column from a table using the DROP COLUMN command (e.g., ALTER TABLE table_name DROP COLUMN column_name;).

Thus, all of the options (a), (b), and (c) are tasks that can be performed using the ALTER clause. Therefore, the correct answer is:

(d) All of the mentioned (since all the functions listed can be performed by the ALTER clause).