Free Databases MCQs with Answers
210 Databases MCQs from Computer Science and IT, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Databases cover tables, records, fields, keys and relationships, together with database management systems and relational database design. The subject includes primary and foreign keys, normalization, SQL commands such as SELECT, INSERT, UPDATE and DELETE, queries, forms and reports, while distinguishing a database from a spreadsheet used for simple tabular data.
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210 questions · page 11 of 11
- A. Insertion
- B. Modification
- C. Deletion of an entity cash attribute must have
- D. All of them
Explanation: A transitive dependency occurs in a database table when the value of one attribute indirectly determines the value of another attribute…
Correct answer: All of them- A. Only one value
- B. More than one value
- C. No repeating groups
- D. Both (a) & (c)
Explanation: In a relational database, an entity represents a real-world object or concept (e.g., customer, product).
Correct answer: Only one value- A. Only one
- B. Where it don't belong
- C. Where it belongs
- D. When it originates
Explanation: Where it belongs is the most likely answer. This refers to the process of data normalization in relational databases.
Correct answer: Where it belongs- A. The primary key consists of only one attribute
- B. Non-key attribute exists in the relation
- C. Every non-key attribute is functionally dependent on the full set of primary key attributes
- D. All of these
- E. None of these
Explanation: Second normal form (2NF) is a level of database normalization that ensures a relation eliminates partial dependencies.
Correct answer: Every non-key attribute is functionally dependent on the full set of primary key attributes- A. Insertion anomaly
- B. Deletion anomaly
- C. Modification anomaly
- D. Updating anomaly
Explanation: A modification anomaly occurs when modifying a single record requires changes to multiple records in a database.
Correct answer: Modification anomaly- A. No primary key attribute can be null
- B. Each entity must have a primary key
- C. Primary key must have only one attribute
Explanation: The entity integrity rule ensures that every table in a relational database has a primary key, and that the primary key cannot contain…
Correct answer: Each entity must have a primary key- A. A → C
- B. B → C
- C. (A, B) is a composite determinant
- D. C is a determinant
Explanation: This is the correct answer. A composite determinant means that both A and B together determine C uniquely.
Correct answer: (A, B) is a composite determinant- A. split the relation into two relations, each with a single theme
- B. change the theme
- C. create a new theme
- D. add a composite key
Explanation: Multivalued dependencies (MVDs) occur in a relational database schema when a determinant attribute (or set of attributes) determines…
Correct answer: split the relation into two relations, each with a single theme- A. always
- B. commonly
- C. seldom
- D. never
Explanation: Multivalued dependencies (MVDs) are a type of dependency that can occur in relational databases.
Correct answer: commonly- A. Transitive dependency
- B. Full functional dependency
- C. Partial dependency
- D. Prime functional dependency
Explanation: A partial dependency is exactly what the question describes. It is a dependency where a set of attributes, that is not a candidate key…
Correct answer: Partial dependency