Question

Which of the following are Data Definition Language statements?
A. CREATE
B. INSERT
C. ALTER
D. DROP
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, C and D only
• C. A, B, C and D
• D. B, C and D only

Hint:

Ask yourself: Does this command change the structural blueprint of the database?
- Yes $\rightarrow$ DDL (CREATE, ALTER, DROP).
- No, it only works with the records/data values $\rightarrow$ DML (INSERT, UPDATE, DELETE).

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to classify four SQL commands (CREATE, INSERT, ALTER, DROP) and identify which of them belong to the Data Definition Language (DDL) subset of SQL commands.

Step 2: Classifying SQL Sub-Languages:
- Data Definition Language (DDL): Commands used to define, alter, or drop the structure of database schemas, tables, and views. Examples include CREATE, ALTER, DROP, and TRUNCATE.
- Data Manipulation Language (DML): Commands used to manage and manipulate the actual data contained within existing tables. Examples include SELECT, INSERT, UPDATE, and DELETE.

Step 3: Detailed Explanation:
Let us analyze the four commands:
- A. CREATE: Used to create a new table or schema structure. This is a DDL command.
- B. INSERT: Used to add new rows of data into a table. This does not change the table structure, only the records inside. This is a DML command.
- C. ALTER: Used to modify an existing table's schema structure (like adding or renaming columns). This is a DDL command.
- D. DROP: Used to delete an entire table structure from the database. This is a DDL command.
- Combining our DDL commands gives us A, C, and D.

Step 4: Final Answer:
The DDL statements are CREATE, ALTER, and DROP (A, C, and D).
Hence, option (B) is the correct choice.