I am using spring data r2dbc in my new project and need to connect multiple data sources like A data source and B data source.
Is there a way to connect multiple data sources using r2dbc?
Could I get an example or a document if there is a way?
My stacks are below:
Spring Boot 2.3.0.M4
Spring WebFlux
Spring Data R2DBC
If you want to use multiple datasources in a single application, check my multi r2dbc connection factories example.
If you need a multi-tenant like feature check this multi-tenancy-r2dbc example.
I solved this issue using AbstractRoutingConnectionFactory you can check Add support for AbstractRoutingConnectionFactory
Related
In My Application, Using the below technologies
Spring boot 2.7.x
Cassandra
spring batch 5. x
java 11
As part of this, I need to extract data from the Cassandra database and need to write out the file
so here I need to use queries to fetch data so
just want to know what is the best way to maintain all queries at one place so any query changes come in the future, I shouldn't build the app rather just need to modify the query.
Using a repository class is necessary. If you are using JPA i recommend using a repository for each Entity class. With JDBC it is possible to create a single repository which contains all the queries. To access the query methodes i would use a service class. In this way your code is structured well and maintainable for future changes.
I created user in oracle database and I am trying to create session but I find many ways in spring boot so what is the easy way if I want to create classe connections using the Username and Password ?
You can jdbc template, spring data JDBC or spring data JPA, well depending on your use case.
If your data model is quite complex, you should avoid using the JDBC template as you will need to write prepared statements which can be cumbersome. JPA will allow you to use object-oriented programming principles and also will help you map the entities to your database columns.
For example, if you are going to use spring data JPA, you need to set the application properties as follows:
spring.datasource.type=oracle.oracleucp.jdbc.UCPDataSource
spring.datasource.oracleucp.connection-factory-class-name=oracle.jdbc.pool.OracleDataSource
spring.datasource.oracleucp.sql-for-validate-connection=select * from dual
spring.datasource.oracleucp.connection-pool-name=UcpPoolBooks
spring.datasource.oracleucp.initial-pool-size=5
spring.datasource.oracleucp.min-pool-size=5
spring.datasource.oracleucp.max-pool-size=10
This would behind the scene create an Oracle Datasource. In this example, we are using Oracle Universal Connection Pooling. You can also use HikariCP which is quite popular.
check this out
If you want to use UCP with above properties then you must have SpringBoot version higher than 2.4.0.
Check out the Spring Boot code sample on GitHub.
I am using Spring Boot 2.5.0 for one of my test projects and need to get some data from one of the transaction tables. I need only latest record per group from this table. This problem has a solution given multiple times on SO, one of which is https://stackoverflow.com/a/1313293/841221.
However, I want to implement the same using Spring Boot Data JPA and not using a native query as using a native query would make me lose database independence.
Can someone please help me?
Can we use multiple datasources with jdbi.
Will the configuration will be same as what we have with JPA : https://www.baeldung.com/spring-data-jpa-multiple-databases
So, in first, you can set more than one database for your application with JDBI, exactely like JDBC. You just have to set them inside your application.properties.
Second, if you want to use JDBI, you'll use a kind of classical queries, instead of a dialect for JPA/hibernate inside repositories.
You can read this discussion to compare them : Benchmarking spring data vs JDBI in select from postgres Database
I have a multitenant system currently working with python. I have different schemas for different tenants. Now we are planning to change the system to spring boot.
How can we change/select the schema based on the request in JPA/Hibernate?
You can set the following property dynamically -
spring.jpa.properties.hibernate.default_schema=MYSCHEMA. For more advanced concept of using multiple datasources take a look at AbstractRoutingDatasource