CODEWITHSUNDEEP
spring-boothibernatejpa
Jupp56
Jupp56

Reputation: 29

How to configure multiple database-platforms in spring boot

I have got a Spring Boot project with two data sources, one DB2 and one Postgres. I configured that, but have a problem:

The auto-detection for the database type does not work on the DB2 (in any project) unless I specify the database dialect using spring.jpa.database-platform = org.hibernate.dialect.DB2390Dialect.

But how do I specify that for only one of the database connections? Or how do I specify the other one independently?

Additional info to give you more info on my project structure: I seperated the databases roughly according to this tutorial, although I do not use the ChainedTransactionManager: https://medium.com/preplaced/distributed-transaction-management-for-multiple-databases-with-springboot-jpa-and-hibernate-cde4e1b298e4 I use the same basic project structure and almost unchanged configuration files.

Upvotes: 0

Views: 3104

Answers (1)

Jupp56
Jupp56

Reputation: 29

Ok, I found the answer myself and want to post it for the case that anyone else has the same question.

The answer lies in the config file for each database, i.e. the DB2Config.java file mentioned in the tutorial mentioned in the question.

While I'm at it, I'll inadvertedly also answer the question "how do I manipulate any of the spring.jpa properties for several databases independently".

In the example, the following method gets called:

@Bean
public LocalContainerEntityManagerFactoryBean db2EntityManagerFactory(
    @Qualifier(“db2DataSource”) DataSource db2DataSource, 
    EntityManagerFactoryBuilder builder
) {    
    return builder
        .dataSource(db2DataSource)
        .packages(“com.preplaced.multidbconnectionconfig.model.db2”)
        .persistenceUnit(“db2”)
        .build();
}

While configuring the datasource and the package our model lies in, we can also inject additional configuration. After calling .packages(...), we can set a propertiesMap that can contain everything we would normally set via spring.jpa in the application.properties file. If we want to set the DB2390Dialect, the method could now look like this (with the possibility to easily add further configuration):

@Bean
public LocalContainerEntityManagerFactoryBean db2EntityManagerFactory(
    @Qualifier(“db2DataSource”) DataSource db2DataSource, 
    EntityManagerFactoryBuilder builder
) {
    HashMap<String, String> propertiesMap = new HashMap<String, String>();
    propertiesMap.put("hibernate.dialect", "org.hibernate.dialect.DB2390Dialect");
    return builder
        .dataSource(db2DataSource)
        .packages(“com.preplaced.multidbconnectionconfig.model.db2”)
        .properties(propertiesMap)
        .persistenceUnit(“db2”)
        .build();
}

Note that "hibernate.dialect" seems to work (instead of "database-platform").

Upvotes: 2

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