How to configure multiple Databases

[codejanovic]

Hello everyone,

i am struggling to setup ebean with multiple Databases, where only for one of those Databases should be actively migrated by ebean. All other databases should not be migrated and are only there for manual querying in readonly mode.

I thought the migrations are only run for/against the "default" database, but it runs for every database.

So thats how my application.properties look like:

ebean.dbSchema= public
ebean.ddlMode= create
ebean.migration.run= true

datasource.default=db
datasource.db.username= someuser
datasource.db.password= somepassword
datasource.db.url= jdbc:postgresql://localhost:5432/db

datasource.api.username= someuser
datasource.api.password= somepassword
datasource.api.url= jdbc:postgresql://localhost:6432/db

datasource.batch.username= someuser
datasource.batch.password= somepassword
datasource.batch.url= jdbc:postgresql://localhost:6433/db

datasource.quartz.username= someuser
datasource.quartz.password= somepassword
datasource.quartz.url= jdbc:postgresql://localhost:6434/db

datasource.c1.username= someuser
datasource.c1.password= somepassword
datasource.c1.url= jdbc:sqlserver://localhost:6435;instanceName=db;databaseName=db;encrypt=true;trustServerCertificate=true

Sadly, running the migration creation will generate Migrations for all created entities, regardless of which Database they are from.

public class GenerateDbMigration {

    public static void main(String[] args) throws IOException {

        DbMigration dbMigration = DbMigration.create();
        dbMigration.setPlatform(Platform.POSTGRES);

        dbMigration.generateMigration();
    }
}

Is there something i am missing or is ebean designed to just run migrations against every database that is configured without any optout capability ?

Cheers,
Aleks

[codejanovic]

So with the help from others I found out how to simply manually control the migrations to process:

        var newsletterDatabaseConfig = Config.forPath("datasource.db");
        var migrationConfig = new MigrationConfig();
        migrationConfig.setDbUsername(newsletterDatabaseConfig.get("username"));
        migrationConfig.setDbPassword(newsletterDatabaseConfig.get("password"));
        migrationConfig.setDbUrl(newsletterDatabaseConfig.get("url"));
        migrationConfig.setDbSchema("public");

        var migrationRunner = new MigrationRunner(migrationConfig);
        migrationRunner.run();

and turning off automatic migration

ebean.migration.run= false

But i could not yet figure out how to tell DbMigration to only migrate a single database instead of all of them.

[codejanovic]

Okay, looks like I found out how to specify a certain database to run db migrations for:

public class GenerateDbMigration {

    public static void main(String[] args) throws IOException {

        DbMigration dbMigration = DbMigration.create();
        dbMigration.setPlatform(Platform.POSTGRES);
        dbMigration.setServer(DB.getDefault());                  <<-------
        dbMigration.generateMigration();
    }
}

So now it looks like everything works as expected now! Maybe this will help some other folks in the future