Relationship design patterns in GraphQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a one-to-one relationship in database design?

A one-to-one relationship means each record in one table is linked to exactly one record in another table. It's like having a unique ID card for each person.

beginner

Explain a one-to-many relationship with an example.

In a one-to-many relationship, one record in a table can be linked to many records in another table. For example, one author can write many books.

intermediate

What is a many-to-many relationship and how is it usually implemented?

Many-to-many means multiple records in one table relate to multiple records in another. It's often done using a join table that connects the two tables.

intermediate

How does a GraphQL schema represent a one-to-many relationship?

GraphQL uses fields that return lists of related objects. For example, a type Author can have a field books that returns a list of Book objects.

beginner

Why is it important to design relationships carefully in databases?

Good relationship design helps keep data organized, avoids duplication, and makes queries faster and easier to write.

Which relationship pattern allows multiple records in one table to relate to multiple records in another?

A One-to-one

B One-to-many

C Many-to-many

D None of the above

Many-to-many relationships connect multiple records from both tables, often using a join table.

In GraphQL, how do you represent a one-to-many relationship?

A Using a field that returns a single object

B Using scalar types only

C Using enums

D Using a field that returns a list of objects

A one-to-many relationship is represented by a field returning a list of related objects.

What is the purpose of a join table in many-to-many relationships?

A To store unrelated data

B To connect records from two tables

C To speed up queries by caching

D To store user permissions

Join tables link records from two tables in many-to-many relationships.

Which of these is NOT a common relationship pattern in databases?

A Many-to-zero

B One-to-many

C Many-to-many

D One-to-one

Many-to-zero is not a recognized relationship pattern.

Why should relationships be designed carefully in databases?

A To avoid data duplication and improve query speed

B To make data messy

C To confuse users

D To increase storage space

Careful design avoids duplication and makes data easier to manage and query.

Describe the three main types of relationship design patterns in databases and give a simple example for each.

Think about how many records in one table connect to records in another.

Explain how you would represent a many-to-many relationship in a GraphQL schema.

Consider how GraphQL fields can return lists to show multiple connections.