@OneToOne relationship in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a one-to-one relationship in a Spring Boot entity.

Spring Boot

public class User {
    @[1]
    private Profile profile;
}

Drag options to blanks, or click blank then click option'

AOneToOne

BManyToMany

COneToMany

DManyToOne

Attempts:

3 left

💡 Hint

Common Mistakes

Using @OneToMany or @ManyToOne which define different relationships.

Forgetting the '@' symbol before the annotation.

The @OneToOne annotation defines a one-to-one relationship between two entities.

2fill in blank

medium

Complete the code to specify the owning side of a one-to-one relationship with a join column.

Spring Boot

public class User {
    @OneToOne
    @[1](name = "profile_id")
    private Profile profile;
}

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AMappedBy

BJoinTable

CColumn

DJoinColumn

Attempts:

3 left

💡 Hint

Common Mistakes

Using @JoinTable instead of @JoinColumn for one-to-one relationships.

Confusing @Column with @JoinColumn.

The @JoinColumn annotation specifies the foreign key column in the owning entity.

3fill in blank

hard

Fix the error in the mappedBy attribute to correctly define the inverse side of the one-to-one relationship.

Spring Boot

public class Profile {
    @OneToOne(mappedBy = "[1]")
    private User user;
}

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AprofileId

Buser

Cprofile

DuserId

Attempts:

3 left

💡 Hint

Common Mistakes

Using the class name instead of the field name in mappedBy.

Using the wrong field name that does not exist in the owning entity.

The mappedBy value should be the name of the field in the owning entity that owns the relationship, here 'profile'.

4fill in blank

hard

Fill both blanks to complete the bidirectional one-to-one relationship between User and Profile.

Spring Boot

public class User {
    @OneToOne
    @[1](name = "profile_id")
    private Profile profile;
}

public class Profile {
    @OneToOne(mappedBy = "[2]")
    private User user;
}

Drag options to blanks, or click blank then click option'

AJoinColumn

BJoinTable

Cprofile

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up JoinColumn and JoinTable annotations.

Using the wrong field name in mappedBy.

The owning side uses @JoinColumn and the inverse side uses mappedBy with the owning side's field name.

5fill in blank

hard

Fill all three blanks to create a one-to-one relationship with cascade and fetch type settings.

Spring Boot

public class User {
    @OneToOne(cascade = CascadeType.[1], fetch = FetchType.[2])
    @JoinColumn(name = "profile_id")
    private Profile [3];
}

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AALL

BEAGER

Cprofile

DLAZY

Attempts:

3 left

💡 Hint

Common Mistakes

Using LAZY fetch when eager loading is intended.

Using incorrect cascade types like PERSIST only.

Naming the field something other than 'profile'.

cascade = CascadeType.ALL applies all cascade operations, fetch = FetchType.EAGER loads the related entity immediately, and the field name is 'profile'.