Migrate references from one collection to other

I am trying to migrate a collection from my local instance to a weaviate docker instance. The code specified in the documentation does not take into account the cross-reference property and throws an error when i try to migrate. Any solutions to this?

i was using the following code where i added the relation to the Object properties, but this results in a batch error for some reason. The collections without cross references work fine.

from typing import List, Optional
from tqdm import tqdm

from weaviate import Client

def migrate_data_from_weaviate_to_weaviate(
    client_src: Client,
    client_tgt: Client,
    from_class_name: str,
    to_class_name: str,
    from_tenant: Optional[str] = None,
    to_tenant: Optional[str] = None,
    limit: int = 1000,
    batch_size: int = 100,
    after_uuid: Optional[str] = None,
    count: int = 0,
) -> None:
    Migrate Weaviate data from a Source Weaviate to a Target Weaviate. This function
    allows to migrate data in 4 different configs:
            1. Class -> Class
            2. Class -> Tenant
            3. Tenant -> Class
            4. Tenant -> Tenant
    Note that this is mean to migrate data that has no cross-references properties, if
    you have cross-references for the class to migrate some changes might be needed for
    this script.

    client_src: Client
            The Source Weaviate Client object instance from which to query the data
            (including the UUID and the underlying vector, if one is present.)
    client_tgt: Client
            The Target Weaviate Client object instance to which to ingest the data.
            NOTE: The batch config is going to be overridden in this function. If you want
            to keep your previous config of the batch, you can remove the `batch.configure`
            call in this function.
    from_class_name: str
            The Source Weaviate class that should be migrated.
    to_class_name: str
            The Target Weaviate class that should host the Source Weaviate data.
    from_tenant: Optional[str] = None
            The Source Weaviate class tenant that that should be migrated. If it is None,
            then it means that the Source class has no Multi-Tenancy enabled and the whole
            class needs to be migrated.
            By default None
    to_tenant: Optional[str] = None
            The Target Weaviate class tenant that should host the migrated data.mIf it is
            None then it means that Target Weaviate has no Multi-Tenancy enabled and the
            data from the Source Weaviate will be in non-Multi-Tenancy class.
            By default None
    limit: int = 500
            The limit used for quering data from Source Weaviate.
            NOTE: Do not set to high value to avoid long requests.
    batch_size: int = 50
            The batch size configured for the Target Weaviate.
            NOTE: Do not set to high value to avoid long requests.
    after_uuid: Optional[str] = None
            The after UUID to be used in cursor API. It is meant to be used in case the script
            faild in the middle of the process of migration. Leave it to None on first run.
            By default None
    count: int = 0
            The number of objects that were already ingested in the Target Weaviate. It is
            meant to be used in case the script faild in the middle of the process of migration,
            and is used ONLY for the progress bar. Can be ignored.

    relationName = "relatedObject"
    # get source class properties
    properties = [
        prop["name"] for prop in client_src.schema.get(from_class_name)["properties"]
                + " {... on "
                + "Object_class"
                + " {data}}")

    # get number of items in the class/tenant
    obj_count_query = client_src.query.aggregate(
    if from_tenant is not None:
        obj_count_query = obj_count_query.with_tenant(from_tenant)
    resp = obj_count_query.do()
    num_objects = resp["data"]["Aggregate"][from_class_name][0]["meta"][

        # configure Target Weaviate Batch
        additional_item_config = {"tenant": to_tenant}
        with client_tgt.batch as target_batch, tqdm(total=(num_objects - count)) as pbar:
            # helper function to ingest data into Target Weaviate
            def ingest_data_in_batches(objects: List[dict]) -> str:
                Ingest data into Target Weaviate using Batch API.

                objects: List[dict]
                        A list of Waviate objects from the Source Weaviate, the list conatins
                        all objects of the current Source Weaviate page.
                        Cannot be empty list!!!

                        The last UUID in the Page to be used with cursor API feature.

                for obj in objects:
                    weaviate_obj = obj.copy()
                    vector = weaviate_obj["_additional"]["vector"]
                    uuid = weaviate_obj["_additional"]["id"]
                    del weaviate_obj["_additional"]

                    if len(vector) == 0:
                return uuid

            # migrate data
            while True:
                query = (
                        class_name=from_class_name, properties=properties
                    .with_additional(["vector", "id"])
                # if after_uuid:
                #     query = query.with_after(after_uuid)
                if from_tenant:
                    query = query.with_tenant(from_tenant)
                source_data = query.do()

                if "errors" in source_data:
                    raise Exception(
                        f"Failed to get data after object UUID '{after_uuid}' for class '{from_class_name}'",
                        f" from '{from_tenant}'!\n" if from_tenant else "\n",
                page_object = source_data["data"]["Get"][from_class_name]

                if len(page_object) == 0:
                after_uuid = ingest_data_in_batches(objects=page_object)
            f"Something went wrong. The last after_uuid was: '{after_uuid}' for Source Weaviate "
            f"class {from_class_name}"
            f" from tenant {from_tenant}! "
            if from_tenant
            else ". "
            f"The Target Weaviate class was {to_class_name}"
            f" with tenant {to_tenant}!\n"
            if to_tenant
            else "!\n"
        # The migration function uses the batch API in a context manager and when it exits
        # the context manager it also shuts down the BatchExecutor, so we can re-start it here.
        # It gets automatically started when entering a new context manager but prints a warning.
        # It is started in 'finally' in case there is a re-try mechanism on errors

Hi @Bigdwarf43 !

We are working on improving that script as this is a common request.

Thanks for pointing it out.

I will get back to you when we have more on that.