Which of the following creates and maintains the schema of a database?Data Manipulation LanguageData Definition LanguageData Control LanguageNone of the above

Step 1: Break Down the Problem

To solve this question, we need to understand the functions of the different types of languages used in database management systems:

1. Data Manipulation Language (DML): This language is used for managing and manipulating data within the database (e.g., SELECT, INSERT, UPDATE, DELETE).

2. Data Definition Language (DDL): This language is responsible for defining and maintaining the database schema and structure (e.g., CREATE TABLE, ALTER TABLE, DROP TABLE).

3. Data Control Language (DCL): This language deals with the rights, permissions, and other controls of the database system (e.g., GRANT, REVOKE).

Step 2: Relevant Concepts

From the definitions above, it is evident that:

• DML is not related to schema maintenance.
• DCL also does not deal with the schema but rather with permissions.
• DDL specifically creates and modifies the schema of the database.

Step 3: Analysis and Detail

Given that the question asks about the creation and maintenance of a database schema, our focus is on DDL.

• Example:
  • To create a table, we use a DDL command: $\text{CREATE TABLE Students (ID INT, Name VARCHAR(50));}$
  • To modify the structure of an existing table, we can use: $\text{ALTER TABLE Students ADD Age INT;}$

Step 4: Verify and Summarize

Thus, after analyzing each option and understanding their roles, it is clear that the Data Definition Language (DDL) is responsible for creating and maintaining the schema of a database.

Final Answer

The correct answer to the question is Data Definition Language (DDL).