topic Re: calculate difference between two columns using tMap in Talend Studio

calculate difference between two columns using tMap

Cherichoc- — Sat, 16 Nov 2024 04:16:20 GMT

One extraction is from Json and the other from an existing table. I want to great a variable in tmap that will be added In the output
JSON    ExistingTable OutputVar
Latitude    latitude    latitude
-24.50    -24.10 0.40

Then if the variable difference is greater than 0.50 use the JSON data. I can use the tFilter row for that

Re: calculate difference between two columns using tMap

Anonymous — Fri, 25 Oct 2019 14:57:56 GMT

The problem you have here is linking the two datasets. Do you have a key that can join them?

Re: calculate difference between two columns using tMap

Cherichoc- — Thu, 31 Oct 2019 05:23:33 GMT

They are joined by deviceID with both longitude and latitude

tExtractJasonField>>>>tMap<<<<<<tDBinput

I need to create variable that will calculate the [existing coordinates(from tdbinput) minus new coordinates(from jSon)]

Re: calculate difference between two columns using tMap

Anonymous — Thu, 31 Oct 2019 09:39:34 GMT

Then join the data using the tMap and subtract one from the other.

Re: calculate difference between two columns using tMap

Cherichoc- — Thu, 31 Oct 2019 10:42:36 GMT

row1.latitude - row2.latitude is not working

Re: calculate difference between two columns using tMap

Anonymous — Thu, 31 Oct 2019 11:15:17 GMT

What is the data type of your GPS columns? I suspect that they might be Strings. They need to be Doubles

Re: calculate difference between two columns using tMap

Cherichoc- — Thu, 31 Oct 2019 12:00:08 GMT

datatype is double

Re: calculate difference between two columns using tMap

Anonymous — Thu, 31 Oct 2019 14:15:51 GMT

Subtraction should work then. Can you show the tMap you are trying this in? I'll need to see the whole screen so that I can see data types and the expressions that are used