One-to-one (hasOne, belongsTo) in Laravel - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the hasOne relationship represent in Laravel?

The hasOne relationship means one model owns exactly one related model. For example, a User has one Profile.

beginner

What is the purpose of the belongsTo relationship in Laravel?

The belongsTo relationship means a model belongs to another model. For example, a Profile belongs to a User.

beginner

How do you define a one-to-one relationship from User to Profile using hasOne?

In the User model, add a method:<br><pre>public function profile() {<br>  return $this->hasOne(Profile::class);<br>}</pre>

beginner

How do you define the inverse one-to-one relationship from Profile to User using belongsTo?

In the Profile model, add a method:<br><pre>public function user() {<br>  return $this->belongsTo(User::class);<br>}</pre>

intermediate

Why is it important to use hasOne and belongsTo correctly in Laravel?

Using these correctly helps Laravel know how to join tables and fetch related data easily. It keeps your code clean and your database queries efficient.

Which Laravel method defines the model that owns the relationship in a one-to-one setup?

A hasOne

B belongsTo

C hasMany

D morphOne

hasOne defines the owning side of a one-to-one relationship.

In a one-to-one relationship, which method should be used in the child model to link back to the parent?

A hasOne

B belongsToMany

C belongsTo

D hasMany

belongsTo is used in the child model to point back to the parent.

If a User has one Profile, where should the foreign key be stored?

A In the users table

B In the profiles table

C In a pivot table

D No foreign key needed

The foreign key is stored in the related model's table, here the profiles table.

Which of these is NOT a valid Laravel relationship method?

A hasTwo

B belongsTo

C hasOne

D belongsToMany

hasTwo is not a Laravel relationship method.

What does the belongsTo method return in Laravel?

A A boolean value

B A collection of models

C The related model instance

D A query builder for the related model

belongsTo returns a query builder to fetch the related model.

Explain how to set up a one-to-one relationship between two Laravel models using hasOne and belongsTo.

Think about which model owns the other and where the foreign key lives.

Describe why using one-to-one relationships properly improves your Laravel application's code and database queries.

Consider how Laravel uses these relationships behind the scenes.