如何在Jooq中将millis转换为日期，并按月和年分组？

import static org.jooq.impl.DSL.*;

// ...

// 将毫秒数转换为日期，并按月分组
Result<Record2<Date, Integer>> resultByMonth = 
    create.select(dateTrunc("month", timestamp(millis)).as("month"), count())
          .from(table)
          .groupBy(dateTrunc("month", timestamp(millis)))
          .fetch();

// 将毫秒数转换为日期，并按年分组
Result<Record2<Date, Integer>> resultByYear = 
    create.select(dateTrunc("year", timestamp(millis)).as("year"), count())
          .from(table)
          .groupBy(dateTrunc("year", timestamp(millis)))
          .fetch();