topic Re: [resolved] Filter by max value in Talend Studio

[resolved] Filter by max value

_AnonymousUser — Sat, 16 Nov 2024 12:49:52 GMT

Hello,
I'm novice with Talend and I have a special operation to do, but I don't know how to do it and what component to use.
I have some rows grouped by one column (Column1). For each value of Column1, I want to get the row wich value of another column (Column2) is the most important : Max(Column2)
By example, for the following rows :
Column1 Column2 Column3 Column4 Column5
AAAA 14 EEEEEE FFFFFFF GGGGGG
AAAA 52 HHHHH IIIIIII JJJJJ
AAAA 8 KKKKK LLLLLL MMMMM
BBBB 34 NNNNNN OOOO PPPPP
BBBB 12 QQQQQ RRRRR SSSSS
CCCC 43 TTTTTT UUUUUU VVVVVV
CCCC 16 WWWWW XXXXXX YYYYYY
CCCC 23 ZZZZZZ ZZZZZZ ZZZZZZ
I want to get the following rows :
AAAA 52 HHHHH IIIIIII JJJJJ
BBBB 34 NNNNNN OOOO PPPPP
CCCC 43 TTTTTT UUUUUU VVVVVV
How can I do it ?
I tried to use the tAggregateRow but I don't understand how to use it, the documentation is very poor (or I'm not enough intelligent to understand it).
Someone can help me please ? Thank you to be precise because Talend is completely new for me
Thanks
Lionel

Re: [resolved] Filter by max value

alevy — Tue, 05 Jul 2011 00:25:33 GMT

You should tSort on Column1 and Column2 descending and then use tUniqueRow to pass through only the first row.
(tAggregateRow can only give you max(Column2) grouped by Column1. You would then have to join the result to the whole data flow to get the rest of the column values for the chosen row.)

Re: [resolved] Filter by max value

_AnonymousUser — Tue, 05 Jul 2011 12:53:25 GMT

You should tSort on Column1 and Column2 descending and then use tUniqueRow to pass through only the first row.
(tAggregateRow can only give you max(Column2) grouped by Column1. You would then have to join the result to the whole data flow to get the rest of the column values for the chosen row.)

Tank you very much, it works !!!