"track": "foreignkeyname"
The track instruction can be used to record old items’ ids and their new ids, so that they can be retrieved later. It is used in conjunction with the match rule, placed in another ruleset.
This ensures that foreign keys will still relate to the same item, even if their ids are changed.
Sync and sync-transform are strictly related instructions and they are used together.
Sync changes the migration behaviour, updating items rather than creating new ones. The items that need to be updated must have been tracked:
"sync": {
"from": "tracking_name",
"attribute": "id"
}
Then, instead of using transform, we will use sync-transform:
"sync-transform": {
"new_column": "old_column"
},
"sync": {
"from": "tracking_name",
"attribute": "id"
}