TYPO3 Extension not fitting the Extbase Schema - typo3

Question

Since the implementation of Doctrines DBAL we now can use different data-sources/connections (Hooray!).
We'd now like to embed one of our services within TYPO3 using this new feature.
The problem now is, that the domain models in this secondary database don't match the typical Extbase schema. E.g. it does't use int IDs nor are these models nested by any kind of parent ID.
Does anyone have experiences with this use-case or has an example?
Or do I have to setup an complete parallel Doctrine ORM to handle those models?

Answer 1

You could try to map your database fields, like here: https://docs.typo3.org/typo3cms/ExtbaseFluidBook/6-Persistence/4-use-foreign-data-sources.html

Answer 2

I am not sure I understood your question correctly but we had a similar case. What we did is we added the second database in the connections.
LocalConfiguration.php
'DB' => [
'Connections' => [
'Default' => [
'charset' => 'utf8',
'dbname' => 'default_dbname',
'driver' => 'mysqli',
'host' => 'default_dbhost',
'password' => 'default_dbpwasswd',
'user' => 'default_dbuser',
],
'Secondary' => [
'charset' => 'utf8',
'dbname' => 'secondary_dbname',
'driver' => 'mysqli',
'host' => 'secondary_dbhost',
'password' => 'secondary_dbpasswd',
'user' => 'secondary_dbuser',
],
],
],
Then added a custom class that gets the data from the Database with the Query Builder
You first have to open a connection to your database, then create a query Builder Object for that connection in the class you use to get the data.
/**
* #var Connection
*/
private $connection;
$connectionPool = GeneralUtility::makeInstance(ConnectionPool::class);
$this->secondaryConnection = $connectionPool->getConnectionByName('Secondary');
$queryBuilder = $this->secondaryConnection->createQueryBuilder();
// now you can get the data with query statements as linked above
$statement = $queryBuilder->select('your_field')->from('your_table')->execute();
while ($row = $statement->fetch()) {
$myObjects[] = new \Vendor\Extension\Domain\Model\ExternalObject($row);
}
I cast each result row to a "ExternalObject" Model that I added, it mapped the fields as closely as possible to my conventional Extbase Objects and then was able to use them almost interchangeably.
It depends on the Data you have in your database though, and the things you want to do with them.