Foreign Keys are added as Alternate Keys when upgrading

[pvk-developer]

Environment Details

• SDV version: V1.0.0
• Python version: 3.8
• Operating System: MacOS Darwin

Error Description

When converting the load_demo metadata, this adds the foreign keys as alternate keys, which leads to erroring out later on validation while fitting.

Steps to reproduce

from sdv.demo import load_demo
from sdv.metadata import MultiTableMetadata

metadata, data = load_demo(metadata=True)
metadata.to_json('old_metadata.json')

MultiTableMetadata.upgrade_metadata('old_metadata.json', 'new_metadata.json')

mtm = MultiTableMetadata.load_from_json('new_metadata.json')
mtm

Here is the output of the mtm as json representation:

{
    "tables": {
        "users": {
            "columns": {
                "user_id": {
                    "sdtype": "numerical"
                },
                "country": {
                    "sdtype": "categorical"
                },
                "gender": {
                    "sdtype": "categorical"
                },
                "age": {
                    "sdtype": "numerical",
                    "computer_representation": "Int64"
                }
            },
            "primary_key": "user_id"
        },
        "sessions": {
            "alternate_keys": [
                "user_id"
            ],
            "columns": {
                "session_id": {
                    "sdtype": "numerical"
                },
                "user_id": {
                    "sdtype": "numerical"
                },
                "device": {
                    "sdtype": "categorical"
                },
                "os": {
                    "sdtype": "categorical"
                },
                "minutes": {
                    "sdtype": "numerical",
                    "computer_representation": "Int64"
                }
            },
            "primary_key": "session_id"
        },
        "transactions": {
            "alternate_keys": [
                "session_id"
            ],
            "columns": {
                "transaction_id": {
                    "sdtype": "numerical"
                },
                "session_id": {
                    "sdtype": "numerical"
                },
                "timestamp": {
                    "sdtype": "datetime",
                    "datetime_format": "%Y-%m-%dT%H:%M"
                },
                "amount": {
                    "sdtype": "numerical",
                    "computer_representation": "Float"
                },
                "cancelled": {
                    "sdtype": "boolean"
                }
            },
            "primary_key": "transaction_id"
        }
    },
    "relationships": [
        {
            "parent_table_name": "users",
            "parent_primary_key": "user_id",
            "child_table_name": "sessions",
            "child_foreign_key": "user_id"
        },
        {
            "parent_table_name": "sessions",
            "parent_primary_key": "session_id",
            "child_table_name": "transactions",
            "child_foreign_key": "session_id"
        }
    ],
    "SCHEMA_VERSION": "MULTI_TABLE_V1"
}