Database starter

What is a primary key?

• A primary key is a duplicate identifier for records.
• A primary key is a unique identifier for a record in a database.
• A primary key is a type of foreign key.
• A primary key is an optional field in a database.

What does the "A" in ACID stand for?

• Accessibility

• Actuality

• Availability
• Atomicity

What type of relationship involves a foreign key?

• Referential relationship
• Composite relationship
• Primary relationship

Which of the following best describes a foreign key?

• A field that uniquely identifies each record in a table.

• A field in one table that refers to the primary key in another table.

• A field that is always optional.

• A field that stores only numeric values.

Which property ensures that a transaction is completed in its entirety or not at all?

• Isolation

• Atomicity

• Durability

• Consistency

What is the main purpose of a unique constraint in a database table?

• To allow duplicate values in a column.

• To ensure that all values in a column are unique.

• To create a relationship between two tables.

• To store large amounts of text data.

Which SQL constraint is used to prevent null values in a column?

• PRIMARY KEY

• FOREIGN KEY

• NOT NULL

• UNIQUE

What does the "C" in ACID stand for in database transactions?

• Consistency

• Connection

• Concurrency

• Correctness

Which of the following best describes a composite key?

• A key that allows duplicate values.

• A key that stores only numeric values.

• A key that is always a foreign key.

• A key made up of two or more columns to uniquely identify a record.

Which SQL constraint ensures that a column cannot have duplicate or null values?

• CHECK

• FOREIGN KEY

• PRIMARY KEY

• UNIQUE