13.1.1 Transactions and Multi-DataSources

Given two domain classes such as:

class Movie {
    String title
}

class Book {
    String title
    static mapping = {
        datasource 'books'
    }
}

You can supply the desired data source to @Transactional or @ReadOnly annotations.

import grails.gorm.transactions.ReadOnly
import grails.gorm.transactions.Transactional
import groovy.transform.CompileStatic
@CompileStatic
class BookService {
    @ReadOnly('books')
    List<Book> findAll() {
        Book.where {}.findAll()
    }
    @Transactional('books')
    void save(String title) {
        Book book = new Book(title: title)
        book.save()
        book
    }
}

@CompileStatic
class MovieService {
    @ReadOnly
    List<Movie> findAll() {
        Movie.where {}.findAll()
    }
}