What is the purpose of a query language in a nonprocedural DML?

The purpose of a query language in a nonprocedural Data Manipulation Language (DML) is primarily to retrieve data from a database. Nonprocedural DML allows users to specify the desired outcome of the database operation without needing to outline the exact procedural steps to achieve that outcome.

For instance, in SQL, which is a common example of a query language, users can write queries in a straightforward manner to obtain specific information from one or more tables. The language's abstraction enables users to focus on what data they want, rather than how to access it, making data retrieval more intuitive and efficient.

In contrast, while updating records, defining schema, or controlling access are essential database operations, they do not capture the primary function of a query language, which is centered around retrieving data efficiently and effectively. Each of those operations falls under different aspects of database management practices and is typically handled by other types of statements or commands in the database system.