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javarowetltalend

Talend - generating n multiple rows from 1 row

Background: I'm using Talend to do something (I guess) that is pretty common: generating multiple rows from one. For example:

ID | Name | DateFrom | DateTo

01 | Marco| 01/01/2014 | 04/01/2014

...could be split into:

new_ID | ID | Name | DateFrom | DateTo

01 | 01 | Marco | 01/01/2014 | 02/01/2014

02 | 01 | Marco | 02/01/2014 | 03/01/2014

03 | 01 | Marco | 03/01/2014 | 04/01/2014

The number of outcoming rows is dynamic, depending on the date period in the original row.

Question: how can I do this? Maybe using tSplitRow? I am going to check those periods with tJavaRow. Any suggestions?

Solution

  • Expanding on the answer given by Balazs Gunics

    Your first part is to calculate the number of rows one row will become, easy enough with a date diff function on the to and from dates

    overall view

    calculate number of rows per row

    Part 2 is to pass that value to a tFlowToIterate, and pick it up with a tJavaFlex that will use it in its start code to control a for loop:

    tJavaFlex start:

    int currentId = (Integer)globalMap.get("out1.id");
String currentName = (String)globalMap.get("out1.name");
Long iterations = (Long)globalMap.get("out1.iterations");
Date dateFrom = (java.util.Date)globalMap.get("out1.dateFrom");

for(int i=0; i<((Long)globalMap.get("out1.iterations")); i++) {

    Main

      row2.id = currentId;
  row2.name = currentName;
  row2.dateFrom = TalendDate.addDate(dateFrom, i, "dd");
  row2.dateTo = TalendDate.addDate(dateFrom, i+1, "dd");

    End

    }

    and sample output:

    1|Marco|01-01-2014|02-01-2014
1|Marco|02-01-2014|03-01-2014
1|Marco|03-01-2014|04-01-2014
2|Polo|01-01-2014|02-01-2014
2|Polo|02-01-2014|03-01-2014
2|Polo|03-01-2014|04-01-2014
2|Polo|04-01-2014|05-01-2014
2|Polo|05-01-2014|06-01-2014
2|Polo|06-01-2014|07-01-2014
2|Polo|07-01-2014|08-01-2014
2|Polo|08-01-2014|09-01-2014
2|Polo|09-01-2014|10-01-2014
2|Polo|10-01-2014|11-01-2014
2|Polo|11-01-2014|12-01-2014
2|Polo|12-01-2014|13-01-2014
2|Polo|13-01-2014|14-01-2014
2|Polo|14-01-2014|15-01-2014
2|Polo|15-01-2014|16-01-2014
2|Polo|16-01-2014|17-01-2014
2|Polo|17-01-2014|18-01-2014
2|Polo|18-01-2014|19-01-2014
2|Polo|19-01-2014|20-01-2014
2|Polo|20-01-2014|21-01-2014
2|Polo|21-01-2014|22-01-2014
2|Polo|22-01-2014|23-01-2014
2|Polo|23-01-2014|24-01-2014
2|Polo|24-01-2014|25-01-2014
2|Polo|25-01-2014|26-01-2014
2|Polo|26-01-2014|27-01-2014
2|Polo|27-01-2014|28-01-2014
2|Polo|28-01-2014|29-01-2014
2|Polo|29-01-2014|30-01-2014
2|Polo|30-01-2014|31-01-2014
2|Polo|31-01-2014|01-02-2014