left single match join in spotfire

[Jaime Serrano Jimenez]

Hello,

In aleft single match join in spotfire when there are more than one rowin right table. How is the joinmade which is the criteria for choosing one or other row in right side

Many thanks

[Oliver Drummond]

Hello, Jaime.

 

Unfortunately, there is no criteria for selecting the row on the right side.

Here is what Spotfire documentation says about it:

https://community.spotfire.com/questions/left-single-match-join-spotfire

"Similar to a left outer join but in case of duplicate matches, only one of the right rows are selected. It is undefined which row that gets selected."

Depending on your data, what you can do is create "fake" calculated columns that only has value once your desired criteria are matched. Then, when you create the join, you can add this as one of your join columns.

[Shashank Gurnalkar]

From the documentation:

 

If there are duplicates of the identifiers, only one value from the new data will be kept, and added to the existing rows. That one row seems to be the one which appeared first in the new data. In the above example, the identifier 'c' is duplicated in the new data, so the first record (c,8) will be used in left single match and the other record(c,9) will not be considered.