topic Compare values in current row to the values in previous row in Talend Studio

Compare values in current row to the values in previous row

_AnonymousUser — Wed, 02 May 2012 15:55:23 GMT

hi,
how do i Compare values in current row to the values in previous row?
Please walk me through the steps.
Thanks

Re: Compare values in current row to the values in previous row

Anonymous — Thu, 03 May 2012 03:34:08 GMT

Hi
Use tJavaRow to store the previous row into several context variables.
When it comes to next row, compare the next row with these context variables.
Regards,
Pedro

Re: Compare values in current row to the values in previous row

Anonymous — Thu, 03 May 2012 06:48:00 GMT

Hi,
You could also use the tMemorizeRows component and configure it to memorize just 1 row. This saves you from writing java code.
Regards,
Arno

Re: Compare values in current row to the values in previous row

Anonymous — Mon, 30 Jul 2012 08:28:58 GMT

David,
I had a similar requirement in which I was required to add previous row value to consecutive row...
Sr. No | B | C
1 | 1 | 1
2 | 2 | 3
3 | 3 | 5
4 | 4 | 7
See the summation which is performed in C column.
This could be achieved using tJavaRow and one variable
output_row.C = (Integer)globalMap.get("prevRowVal")+input_row.B;
globalMap.put("prevRowVal",output_row.C);
Hope this would help you to implement yours requirement.
Thanks
Vaibhav

Re: Compare values in current row to the values in previous row

Anonymous — Mon, 30 Jul 2012 08:31:32 GMT

Hi Vaibhav
Thanks for your scenario.
Regards,
Pedro

Re: Compare values in current row to the values in previous row

krengan21 — Mon, 13 Mar 2017 15:01:31 GMT

Hi ,
I am not able to fetch the previous record from tmemorizerow say for example there is two records in mysql table
on_off | real_time_clock
0| 2017-01-01 13:00:00
1|2017-01-01 13:15:00

i need to find the difference between the real time clock when on_off changes from 0 to 1 ie 15 minutes ,I dont know how to fetch the previous record from tMemorizeRow and compare it with the current value of on_off .It will be helpful if you say me how to do it.
Thanks,
kasthuri rengan