What is used to link related tables in a relational database?

What is used to link related tables in a relational database?

• A. Keys
• B. Headers
• C. Bytes
• D. Collations

Answer: (A)

Keys link related tables in a relational database. A primary key uniquely identifies each row in its table, while a foreign key in another table points to that primary key to form a relationship between the two tables. This setup enables you to join data across tables and maintain referential integrity—for example, a Customers table with a CustomerID as the primary key and an Orders table that includes CustomerID as a foreign key to connect each order to its customer. Headers, bytes, and collations don’t create these links. Headers are metadata like column names, bytes are data size, and collations affect text sorting and comparison, not table relationships.

Keys link related tables in a relational database. A primary key uniquely identifies each row in its table, while a foreign key in another table points to that primary key to form a relationship between the two tables. This setup enables you to join data across tables and maintain referential integrity—for example, a Customers table with a CustomerID as the primary key and an Orders table that includes CustomerID as a foreign key to connect each order to its customer.

Headers, bytes, and collations don’t create these links. Headers are metadata like column names, bytes are data size, and collations affect text sorting and comparison, not table relationships.