[
    {
        "name": "category",
        "columns": ["id", "name", "popularity"],
        "contains": [
            {
                "name": "products",
                "columns": ["id", "name", "description"]
            },
            {
                "name": "stock",
                "columns": ["id", "number"]
            }
        ]
    },
    {
        "name": "user",
        "columns": ["id", "username", "email", "password"]
    }
]