@Id and @GeneratedValue for primary keys in Spring Boot - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mark the primary key field in a Spring Boot entity.

Spring Boot

public class User {
    [1]
    private Long id;
}

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

A@Id

B@Entity

C@Column

D@Table

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Entity instead of @Id for the primary key.

Forgetting to annotate the primary key field.

Using @Column or @Table which are for other purposes.

The @Id annotation marks the field as the primary key in a Spring Boot entity.

2fill in blank

medium

Complete the code to automatically generate the primary key value.

Spring Boot

public class User {
    @Id
    [1]
    private Long id;
}

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A@Transient

B@Column(nullable = false)

C@Table(name = "users")

D@GeneratedValue(strategy = GenerationType.AUTO)

Attempts:

3 left

💡 Hint

Common Mistakes

Using @Column instead of @GeneratedValue for key generation.

Omitting the strategy parameter.

Using @Transient which excludes the field from persistence.

The @GeneratedValue annotation with strategy AUTO tells Spring Boot to generate the primary key automatically.

3fill in blank

hard

Fix the error in the code to correctly generate the primary key using identity strategy.

Spring Boot

public class Product {
    @Id
    @GeneratedValue(strategy = [1])
    private Long productId;
}

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AGenerationType.IDENTITY

BGenerationType.AUTO

CGenerationType.SEQUENCE

DGenerationType.TABLE

Attempts:

3 left

💡 Hint

Common Mistakes

Using AUTO instead of IDENTITY when the database requires identity strategy.

Confusing SEQUENCE with IDENTITY.

Omitting the strategy parameter.

GenerationType.IDENTITY tells Spring Boot to use the database identity column for key generation.

4fill in blank

hard

Fill both blanks to define a primary key with sequence generation in a Spring Boot entity.

Spring Boot

public class Order {
    @Id
    @GeneratedValue(strategy = [1], generator = [2])
    private Long orderId;
}

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AGenerationType.SEQUENCE

B"order_seq"

CGenerationType.IDENTITY

D"seq_order"

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing IDENTITY with sequence generator name.

Using generator name without quotes.

Using wrong GenerationType for sequence.

Use GenerationType.SEQUENCE for sequence strategy and specify the sequence generator name as a string.

5fill in blank

hard

Fill all three blanks to define a primary key with sequence generation and sequence generator annotation.

Spring Boot

public class Invoice {
    @Id
    @SequenceGenerator(name = [1], sequenceName = [2], allocationSize = 1)
    @GeneratedValue(strategy = [3], generator = [1])
    private Long invoiceId;
}

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

A"invoice_seq"

B"seq_invoice"

CGenerationType.SEQUENCE

DGenerationType.IDENTITY

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for generator and sequence generator.

Using IDENTITY strategy with sequence generator.

Omitting quotes around string names.

The sequence generator name is "invoice_seq", the sequence name is "seq_invoice", and the strategy is GenerationType.SEQUENCE.