from typing import Any, Dict, List


def validate_item(item: Any) -> str:
    """
    Chech if item is string or number.

    Args:
        item (Any): Item to be checked.

    Returns:
        str: Same or empty string.
    """
    if isinstance(item, str) or isinstance(item, int):
        return item
    return ""


def json_to_csv(data: List[Dict]) -> str:
    """
    Transform JSON data to CSV string.

    Args:
        data (List[Dict]): List of items that will be transformed.

    Returns:
        str: CSV string with header.
    """
    if data:
        header_keys = data[0].keys()
        header = ",".join([f'"{i}"' for i in header_keys])

        rows = []
        for row in data:
            row_data = ",".join([f'"{validate_item(i)}"' for i in row.values()])
            rows.append(row_data)

        body = "\r\n".join(rows)

        return f"{header}\r\n{body}"

    return ""