I have a lot of JPA entities automatically created from a relational database schema.
Is there any way to generate also there corresponding Spring Data Repositories (Repository interfaces)?
You can use Spring Roo to create models and repositories by one command.
http://docs.spring.io/spring-roo/reference/html/intro.html
Wel, it's not for JPA, but I created a tool, EWA, for creating Repositories, Services and Models for Spring Boot + sql2o, a simple db driver, the fastest after pure JDBC.
Related
I want to use SingleStore database with my Spring Boot Application which uses Spring Data JPA. How it can be achieved?
To leverage SingleStoreDB with Spring Boot, you would use the JDBC connectors for both technologies - Spring + SingleStore. If you are using some ORM style features, use the mysql dialect. If you run into issues you can raise them here, on the forum or to support if you're an active customer.
I am trying to understand various dependencies of spring boot.
I have come across three of them:
spring-boot-starter-data-rest
spring-boot-starter-data-jpa
spring-boot-starter-data-jdbc
I would like to know the difference between the three. Tried searching online documents, which say the three are almost related to spring data. how to resolve the confusion?
To add in here I have also found an another dependency
spring-boot-starter-web-services. I think it supports both SOAP and REST. Its just my assumption, I waiting for an explanation
spring-boot-starter-data-jpa is used to access your database with JPA (Java Persistence API)
spring-boot-starter-data-jdbc is used to access your data with jdbc (Java Database Connectivity)
the difference between JPA and JDBC is the level of abstraction. JDBC is more low level, JPA is more 'magic'
and spring-boot-starter-data-rest is used to provide Rest Endpoints on top of your Spring Data repositories.
To do this, you just annotate your spring data repository with a RepositoryRestResource annotation and direct Spring MVC creates the Restful endpoints.
#RepositoryRestResource(collectionResourceRel = "people", path = "people")
public interface PersonRepository extends PagingAndSortingRepository<Person, Long> {
List<Person> findByLastName(#Param("name") String name);
}
This is very handy if you do very CRUD like (Create, Read, Update, Delete) applications.
JPA means "Java Persistence API". It's for querying or saving data in relational databases using object-relational mapping.
REST means "REpresentational State Transfer". It's a style for creating web services that leverages HTTP verbs, a simpler alternative to SOAP.
JDBC starter uses the Spring JdbcTemplate to query or save data in relational databases without relying on object-relational mapping. You write SQL and ask the JdbcTemplate class to execute it in the database using JDBC.
I would say JPA and JDBC starters should be mutually exclusive: either one or the other.
You use REST only if you're writing web services. These may or may not query or persist data in a relational database. I would expect to see both the REST starter and a persistence starter in a pom if a REST service needed persistent data.
Three very different starters.
You ask why Spring Boot has a REST data starter parent that combines the two. In a word: convenience.
I'm working on project, that uses Spring framework (Spring MVC, JDBC etc.) Project is not so big and uses Jetty servlet container, PostgreSQL database with standard DAO classes(sql requests). I need to make it possible to use Spring Boot and Hibernate/Spring JPA with repositories instead SQL queries. I found a few states describes migration to spring boot: https://www.baeldung.com/spring-boot-migration https://3ldn.nl/2016/02/16/spring-boot-in-an-existing-application-part-1/ Now I make small example with Hibernate - generate few Entities and make CRUD operations with Hibernate instead sql queries.
But I need to update existing project for using Spring Boot and I need to use Spring JPA Repositories.
I add spring boot dependencies in dependencyManagment section. What steps I need to do`s next?
I've solved my task and succesfully migrate project to spring boot with JPA/Hibernate.
Its very simple task! and all what you need to migrate is:
0) solve all dependencies issues and remove all tags from boot dependencies.
1) How to use JPA Repositories without Spring Boot
2) How to migrate existing Spring project to Spring Boot
that is all.
We are using Spring Boot with Spring Data JPA with the Transactional annotation for managing transactions.
However, we have a multi-tenant application and for very large customers, we need to put them on a separate dedicated DB.
Is there any way to intercept with TransactionManager is used by the TransactionalAnnotation and dynamically override it per request (depending which tenant is getting updated)?
This is a very useful link for your need, implementing multitenancy in spring boot with spring data Jpa,
It saves the list of tenants in a master(common) database and Hibernate manages the multitenancy datasources (seperate Databases per tenant).
I have spring boot 2.0.2.RELEASE application. Which uses Spring Data JPA Repositories to fetch Data from underlying db.
All I want to configure is that when I use any repository function to fetch data from database it used use stateless session to communicate with DB and fetching data.
I have googled tons of article and other resources but not found any way how to configure and do this.
Kindly guide me to any documentation or any blog or tell me how to configure to achieve the above requirements.