What type of database stores data in separate entities and relates them through common fields?

What type of database stores data in separate entities and relates them through common fields?

• A. NoSQL Database
• B. Flat File
• C. In-Memory Database
• D. Relational Database

Answer: (D)

This question tests how data is modeled and linked across tables. In a relational database, data is stored in separate entities (tables), each representing a distinct type of data. The links between these entities are created through common fields called keys: a primary key in one table uniquely identifies a row, and a foreign key in another table references that primary key to establish a relationship. This structure lets you store related information in focused, well-defined tables and retrieve it together using joins, while keeping data consistent through referential integrity. For example, a customers table can relate to an orders table via a customer_id field. The other options describe different storage approaches: NoSQL databases model data without fixed tables and may handle relationships differently; a flat file stores all data in a single file with a simple structure; an in-memory database describes where data is kept (in memory) and can be relational or not, but the defining feature here is the relational organization through separate tables and keys.

This question tests how data is modeled and linked across tables. In a relational database, data is stored in separate entities (tables), each representing a distinct type of data. The links between these entities are created through common fields called keys: a primary key in one table uniquely identifies a row, and a foreign key in another table references that primary key to establish a relationship. This structure lets you store related information in focused, well-defined tables and retrieve it together using joins, while keeping data consistent through referential integrity. For example, a customers table can relate to an orders table via a customer_id field. The other options describe different storage approaches: NoSQL databases model data without fixed tables and may handle relationships differently; a flat file stores all data in a single file with a simple structure; an in-memory database describes where data is kept (in memory) and can be relational or not, but the defining feature here is the relational organization through separate tables and keys.