table! {
    data (device_id, timestamp) {
        device_id -> Text,
        timestamp -> Timestamp,
        value -> Double,
        battery_status -> Double,
    }
}

table! {
    devices (device_id) {
        device_id -> Text,
        name -> Text,
    }
}

joinable!(data -> devices (device_id));

allow_tables_to_appear_in_same_query!(data, devices,);