Calculate number of days excluding sunday in Hive

问题

I have two timestamps as input. I want to calculate the time difference in hours between those timestamps excluding Sundays.

I can get the number of days using datediff function in hive.

I can get the day of a particular date using from_unixtime(unix_timestamp(startdate), 'EEEE').

But I dont know how to relate those functions to achieve my requirement or is there any other easy way to achieve this.

Thanks in Advance.

回答1:

You can write one custom UDF which takes two columns containing the dates as inputs and counts the difference between the dates excluding sundays.

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Date;
import org.apache.hadoop.hive.ql.exec.UDF;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;

public class IsoYearWeek extends UDF {

  public LongWritable evaluate(Text dateString,Text dateString1) throws ParseException { //takes the two columns as inputs
    SimpleDateFormat date = new SimpleDateFormat("dd/MM/yyyy");
/*  String date1 = "20/07/2016";
    String date2 = "28/07/2016";
*/  int count=0;

    List<Date> dates = new ArrayList<Date>();

    Date  startDate = (Date)date.parse(dateString.toString()); 
    Date  endDate = (Date)date.parse(dateString1.toString());
    long interval = 24*1000 * 60 * 60; // 1 hour in millis
    long endTime =endDate.getTime() ; // create your endtime here, possibly using Calendar or Date
    long curTime = startDate.getTime();
    while (curTime <= endTime) {
        dates.add(new Date(curTime));
        curTime += interval;
    }
    for(int i=0;i<dates.size();i++){
        Date lDate =(Date)dates.get(i);
        if(lDate.getDay()==0){
            count+=1;  //counts the number of sundays in between
        }
    }

        long days_diff = (endDate.getTime()-startDate.getTime())/(24 * 60 * 60 * 1000)-count; //displays the days difference excluding sundays
        return new LongWritable(days_diff);

  }

}

来源：https://stackoverflow.com/questions/38390153/calculate-number-of-days-excluding-sunday-in-hive