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Kotlin – SpringBoot MongoDB – Model One-to-One, One-to-Many Relationships Embedded Documents

loizenai profile image loizenai ・2 min read

Kotlin – SpringBoot MongoDB – Model One-to-One, One-to-Many Relationships Embedded Documents

https://grokonez.com/spring-framework/spring-boot/kotlin-spring-boot/kotlin-springboot-mongodb-model-one-one-one-many-relationships-embedded-documents

With MongoDB, we can structure related data by embedded documents. In general, embedding gives a better performance for read operations. So in the tutorial, JavaSampleApproach will show you way to work with Embedded Documents using SpringBoot by Kotlin language.

I. Technologies

– Kotlin 1.2.20
– Apache Maven 3.5.2
– Spring Tool Suite – Version 3.9.0.RELEASE
– Spring Boot – 1.5.10.RELEASE
– MongoDB: v3.4.1

II. MongoDB – Embedded Documents

Embedded Documents are generally known as denormalized models. It is a way to structure related data in a single document. See below diagram:

kotlin mongodb-embedded-document-structure

In general, we decide to design data as embedded models in case: data contains one-to-one or one-to-many relationships between entities.

With embedding data model, in general, it gives us a better performance for read operations. And we can use a single atomic read/write database operation to request and retrieve or update related data.

However, a weakness point is embedding related data in documents may lead to situations where documents grow after creation.

III. Practice

In the tutorial, we use SpringToolSuite to create a Kotlin SpringBoot project for MongoDB embedded documents:

kotlin mongodb-embedded-document-project structure

Step to do
– Create Kotlin SpringBoot project
– Create Document models
– Create MongoRepository
– Implement Client
– Run and check results

1. Create Kotlin SpringBoot project

Using Spring Tool Suite, create a Kotlin SpringBoot project. Then open pom.xml file, add dependencies:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
 
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
</dependency>

More at:

Kotlin – SpringBoot MongoDB – Model One-to-One, One-to-Many Relationships Embedded Documents

https://grokonez.com/spring-framework/spring-boot/kotlin-spring-boot/kotlin-springboot-mongodb-model-one-one-one-many-relationships-embedded-documents

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