For what additionalTables are used for ?

[Zuzz]

Dear sirs, please, For what additionalTables are used for ?

https://github.com/espocrm/espocrm/blob/master/application/Espo/Core/Templates/Metadata/CategoryTree/entityDefs.json

"additionalTables": {
"{entityType}Path": {
"attributes": {
"id": {
"type": "id",
"dbType": "integer",
"len": 11,
"autoincrement": true,
"unique" : true
},
"ascendorId": {
"type": "foreignId",
"index": true
},
"descendorId": {
"type": "foreignId",
"index": true
}
}
}
}

[yuri]

It's an internal feature. Not listed in the metadata reference, hence to be treated as a non-official feature. It creates an additional table to store additional data.

[Zuzz]

I copied it from CategoryTree.
And additionalTables is used in where array with inCategory select.
Is it nessesary to use additionalTables in tree entity ?

[Zuzz]

https://github.com/espocrm/espocrm/blob/master/application/Espo/Core/Record/Service.php

publicfunctionfind(SearchParams$searchParams, ?FindParams$params = null): RecordCollection

$query = $selectBuilder
->from($this->entityType)
->withStrictAccessControl()
->withSearchParams($preparedSearchParams)
->withAdditionalApplierClassNameList(
$this->createSelectApplierClassNameListProvider()->get($this->entityType)
)
->build();

$preparedSearchParams with inCategory (screenshot in attach) trasfered in $query with additionalTables in where (screenshot in attach )

[Zuzz]

https://github.com/espocrm/espocrm/blob/master/application/Espo/Core/Select/Where/Converter.php

in
private function applyInCategory()

additionalTables generally used:

$pathName = lcfirst($foreignEntity) .'Path';

$queryBuilder->join(
ucfirst($pathName),
$pathName,
[
"{$pathName}.descendorId:" => "{$middleName}.{$key}",
]
);