Index query produces empty table

Hi all
In my hands, the index query node produces an empty data table. I have reduced my workflow a data table input, table indexer and index query to find the cause. However, I was not able to find any difference to the example workflow, which works fine on the same knime 4.1.2 installation.
Does anyone have an idea (see attached WF)?
Input very much appreciated (maybe I have overlooked something super- obvious…)
Thanks,
Attila

Hello GreenGripper,
I guess you have forgotten to include the workflow :slight_smile:
Did you check the “Save original data” option in the Table Indexer node? Are you sure that your query returns any data for the input table? For strings the node automatically does stop word filtering e.g. the or a or and, which then get ignored during searching. So if you only search for these terms the node will return an empty table.
Bye
Tobias

Hi Tobias
Thanks for replying so quickly. I have used identical setting in both nodes (indexer and query) as in the original example WF, which works (in the same .knwf, see upload this time). My query term is just “A”, but also tried with a number (Col1).
Cheers,
Attila

IndexQueryEmptyTableKNIME412.knwf (3.0 MB)


Hello GreenGripper,
the easiest way to solve the problem is by setting the “Save original data” option to Yes. However if you want to save space you can leave the option as No but then you need to specify in the Index Query node on the Result Field to Column Matching tab at least one matching pair where the values of the input table match a value from the query index. This is usually the row id. In addition you need to adapt your query to the required Lucene syntax (see the node description) for example:
Col0:B or Col1:[2000 TO 2100]
will return all rows that have B in Col0 or a value between 2000 and 2100 in Col1. Searching for just A in Col0 won’t work since it is a stop word such as the and an.
See the adapted workflow for the above mentioned changes.
Bye
Tobias

IndexQueryEmptyTableKNIME412_updated.knwf (3.0 MB)

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Hi Tobias
Works like described by you. Thanks for the updated WF and your input.
Kind regards,
Attila

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