Data Engineering Associate with Databricks Practice Exam

How do you specify which database to run commands in SQL?

1. SET DATABASE dbname;

2. USE dbname;

3. SELECT dbname;

4. RUN dbname;

The correct answer is: USE dbname;

The command to specify which database to run SQL commands in is "USE dbname." This command is fundamental in SQL as it defines the active database context for subsequent SQL operations, allowing users to execute queries within that particular database without needing to prefix every command with the database name. When "USE dbname" is executed, it sets the specified database as the default for the session. This means that any SQL operations that follow will interact with objects, such as tables and views, in the designated database until another "USE" command is invoked or the session is terminated. This is particularly useful in environments where multiple databases exist, ensuring the correct context is maintained for data manipulation and retrieval. While other commands might seem relevant at first glance, they do not serve the same purpose of designating a database for command execution. For instance, "SET DATABASE dbname" is not a standard SQL command, making it ineffective for this purpose. "SELECT dbname" would simply attempt to retrieve the name of the database rather than set the context for operations. "RUN dbname" is also an invalid option as it does not align with SQL syntax used for selecting a database.