Java Cassandra异常timeuuid

Question

在java中，我在插入cassandra时遇到这个错误，我还尝试了timestamp数据类型，

那么问题日期是类型，还是java代码？你能建议修改代码吗？

正在读取csv文件。

错误：

Exception in thread "main" com.datastax.driver.core.exceptions.InvalidQueryException: Invalid STRING constant (2012/11/11) for "fl_date" of type timeuuid

结构: fl_date timeuuid，

代码：

    System.out.println("Processing CSV file ...");
    List<Flight> flightList = ProcessFlightsCSV.processFlights("flights_from_pg.csv");

    for (Flight flight : flightList) {

        System.out.println(flight);

        Insert query = QueryBuilder.insertInto("flights")
                .value("id", flight.getId())
                .value("year", flight.getYear())
                .value("fl_date", flight.getFlDate())
                .value("airline_id", flight.getAirlineId())
                .value("carrier", flight.getCarrier())
                .value("fl_num", flight.getFlNum())
                .value("origin_airport_id", flight.getOriginAirportId())
                .value("origin", flight.getOrigin())
                .value("origin_city_name", flight.getOriginCityName())
                .value("origin_state_abr", flight.getOriginStateAbr())
                .value("dest", flight.getDest())
                .value("day_of_month", flight.getDayOfMonth())
                .value("dest_city_name", flight.getDestCityName())
                .value("dest_state_abr", flight.getDestStateAbr())
                .value("dep_time", flight.getDepTime())
                .value("arr_time", flight.getArrTime())
                .value("distance", flight.getDistance())
                ;

        session.execute(query.toString());
    }
}
}

Answer 1

在Cassandra中没有直接的方法可以将字符串-日期-时间转换为TimeUUID。所以你需要从date-time值中生成timeuuid。下面是一个简单的例子：

    long fl_date_in_mili = // some code to get millisecond time from flight.getFlDate(); DO it yourself, As we don't know what kind of datatype it is.
    ...
    ...
    UUID fl_date_time_uuid = UUIDs.endOf(fl_date_in_mili);
    // or
    UUID fl_date_time_uuid = UUIDs.startOf(fl_date_in_mili);

    ...
    ...
    ...
    Insert query = QueryBuilder.insertInto("flights")
            .value("id", flight.getId())
            ......
            .value("fl_date", flDateTimeUUID)
            .value("airline_id", flight.getAirlineId())
            .....

这里我们使用：com.datastax.driver.core.utils.UUIDs；，它可以在datastax cassandra驱动程序中找到。

Answer 2

您需要将日期从字符串YYYY/MM/DD格式转换为以ms为单位的长格式，并将其传递。您可以使用java date实用程序函数对其进行转换。(How to convert a string Date to long millseconds)。