CompTIA DataSys+ (DS0-001)Database FundamentalsMedium
A data engineer is designing a database schema for an e-commerce platform. They have a `Products` table and an `Orders` table. Each order can contain multiple products, and each product can be part of multiple orders. Which type of relationship best describes the interaction between `Products` and `Orders`?
- ASelf-Referencing
- BMany-to-Many
- COne-to-Many
- DOne-to-One
Show answer & explanationAnswer & explanation
Correct answer: B. Many-to-Many
A many-to-many relationship exists when one record in table A can be linked to multiple records in table B, and one record in table B can also be linked to multiple records in table A. In this case, one order has many products, and one product can be on many orders.
Why the other options are wrong
- A. Self-Referencing is when a table relates to itself, typically for hierarchical data (e.g., employee to manager), which is not the case here.
- C. One-to-Many means one record in table A can be linked to multiple in table B, but a record in B links to only one in A (e.g., one customer has many orders).
- D. One-to-One means a single record in one table correlates to exactly one record in another, which is not the case here.
Many-to-Many Relationship
A type of relationship in a relational database where one record in Table A can be associated with multiple records in Table B, and one record in Table B can be associated with multiple records in Table A.
- Requires an intermediary (junction/associative) table to resolve.
- Each record in table A can have multiple matching records in table B.
- Each record in table B can have multiple matching records in table A.
Memory trick: Relationships describe how tables 'talk' to each other.