package example
import grails.gorm.services.Service
@Service(Book)
abstract class BookService {
TestService testRepo
abstract Book save(String title, String author)
void doSomething() {
assert testRepo != null
}
}1 Introduction
Version: 2023.3.0
1 Introduction
MongoDB bridges the gap between key-value stores (which are fast and highly scalable) and traditional RDBMS systems (which provide rich queries and deep functionality).
MongoDB (from "humongous") is a scalable, high-performance, open source, document-oriented database.
This project aims to provide an object-mapping layer on top of Mongo to ease common activities such as:
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Marshalling from Mongo to Groovy/Java types and back again
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Support for GORM dynamic finders, criteria and named queries
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Session-managed transactions
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Validating domain instances backed by the Mongo datastore
1.1 Compatibility with GORM for Hibernate
This implementation tries to be as compatible as possible with GORM for Hibernate. In general you can refer to the GORM documentation for usage information.
The following key features are supported by GORM for Mongo:
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Simple persistence methods
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Dynamic finders
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Criteria queries
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Named queries
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Inheritance
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Embedded types
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Query by example
However, some features are not supported:
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HQL queries
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Composite primary keys
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Many-to-many associations (these can be modelled with a mapping class)
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Any direct interaction with the Hibernate API
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Custom Hibernate user types (custom types are allowed with a different API)
There may be other limitations not mentioned here so in general it shouldn’t be expected that an application based on GORM for Hibernate will "just work" without some tweaking involved. Having said that, the large majority of common GORM functionality is supported.
1.2 Upgrade Notes
Dependency Upgrades
GORM 2023.3 supports Apache Groovy 4.0, Java 17, MongoDB Driver 5.0 and Spring 6.1.x.
Each of these underlying components may have changes that require altering your application. These changes are beyond the scope of this documentation.
Default Autowire By Type inside GORM Data Services
A GORM Service (or a bean) inside GORM DataService will default to autowire by-type, For example:
./app/services/example/BookService.groovy
Please note that with autowire by-type as the default, when multiple beans for same type are found the application with throw Exception. Use the Spring `@Qualifier annotation for Fine-tuning Annotation Based Autowiring with Qualifiers.