What is the domain of an attribute in a relational database model?

The range of values an attribute can take

The number of unique values an attribute can hold

The unique identifier for an attribute

Which of the following is an example of a foreign key?

A key in the 'Orders' table that refers to the 'Customer' table

A key that uniquely identifies a row in the 'Customers' table

A primary key in the 'Orders' table

A key used for internal table indexing

Which statement correctly describes a 'candidate key'?

It is a column that uniquely identifies rows, but it is not the primary key

It is any column that can uniquely identify rows in a table

It is the key used for referencing another table

What is the purpose of the `CREATE DATABASE` statement?

To create a table in the database

What is the purpose of the `DROP DATABASE` command?

To delete a database and all its contents

To delete a specific table from a database

To delete a database connection

What is the purpose of the `ALTER TABLE` command?

To change the structure of an existing table

What is the purpose of the `DISTINCT` clause in SQL?

To select unique values from a column

What does the `GROUP BY` clause do in SQL?

Groups rows based on one or more columns and applies aggregate functions

Filters records by grouping them

Orders the result set by grouping columns

Which of the following SQL commands will give the Cartesian product of two tables?

SELECT FROM table1 INNER JOIN table2

SELECT FROM table1 LEFT JOIN table2

SELECT FROM table1 RIGHT JOIN table2

What is the correct way to connect to an SQL database in Python using the `sqlite3` module?

`conn=sqlite3.connect('database.db')`

`conn=sqlite3.open('database.db')`

What does the `cursor.execute()` function do in Python's `sqlite3` module?

Opens a connection to the database

Fetches all records from the database

Commits the transaction to the database

What is the purpose of the `%s` in the `execute()` method of Python's `sqlite3`?

It is used to represent placeholders for parameters in queries

It formats strings for display purposes

It indicates a SQL query to execute

It closes the database connection

How can you execute a parameterized query in Python using `sqlite3`?

`cursor.execute("SELECT FROM table WHERE column=?", (value,))`

`cursor.execute("SELECT FROM table WHERE column=%s", value)`

`cursor.query("SELECT FROM table WHERE column=:value", (value,))`

`cursor.execute("SELECT FROM table WHERE column=:value", value)`

What does the `fetchone()` method return in Python's `sqlite3` module?

A single row from the result set

The number of rows affected by the query

The next available row in the result set

Assertion (A): The `ALTER TABLE` command can be used to add a new column to an existing table. Reasoning (R): The `ALTER TABLE` command is used to modify the structure of an existing table, such as adding or removing columns.

Both the assertion and reasoning are true, and the reasoning correctly explains the assertion.

Both the assertion and reasoning are true, but the reasoning does not correctly explain the assertion.