निम्नलिखित का सही

Which type of join returns all rows from the left table and matching rows from the right table?

What is a primary key in a relational database?

Which of the following is a property of a relational database?

If every non-key attribute is functionally dependent on the primary key, the relation will be in

A relation is in 2NF if:

Which of the following is a common technique for concurrency control in databases?

In a relational database, what is a foreign key?

What does re.sub(r'(\w+)', r'_\1_', 'hello world') return?

Consider the following Java code snippet 

public class Car {

    private String model;

    private int year;