Which SQL sublanguage defines schema?

Which SQL sublanguage defines schema?

• A. DML
• B. DDL
• C. TCL
• D. DCL

Answer: (B)

Defining the schema involves describing the database structure—what tables exist, what columns they have, their data types, constraints, and relationships. The SQL sublanguage that handles creating and altering that structure is Data Definition Language. Statements like CREATE TABLE, ALTER TABLE, and DROP TABLE are DDL and are used to define or modify the schema itself. Data Manipulation Language is about working with the data inside that structure—SELECT, INSERT, UPDATE, DELETE. Transaction Control manages grouping statements into transactions (COMMIT, ROLLBACK), and Data Control handles permissions (GRANT, REVOKE). So the best fit for defining schema is Data Definition Language.

Defining the schema involves describing the database structure—what tables exist, what columns they have, their data types, constraints, and relationships. The SQL sublanguage that handles creating and altering that structure is Data Definition Language. Statements like CREATE TABLE, ALTER TABLE, and DROP TABLE are DDL and are used to define or modify the schema itself.

Data Manipulation Language is about working with the data inside that structure—SELECT, INSERT, UPDATE, DELETE. Transaction Control manages grouping statements into transactions (COMMIT, ROLLBACK), and Data Control handles permissions (GRANT, REVOKE). So the best fit for defining schema is Data Definition Language.