An Interesting Bug

KNIME Analytics Platform
1

My friend told me about KNIME. This is a awesome Plateform.

I found an interesting Bug.

Right Click on the [ Database Reader ],there is a selection "Data from Database" to show the data.

My table is about 837,010 rows. There is a 10,000 misplace at the  "Row ID" 565,831 which should be 555,831.

But the result of the [ Value Counter ] is right. So I think it's not a big deal.

2

Hi,

thanks for reporting this issue. It would be great if you can tell me what KNIME version, database and jdbc driver you are using.

Thanks for your help,

Tobias

3

Hi,

Thank you for your reply. You are welcome:). I like KNIME. My version is 2.10.4. Database is HANA and the jdbc driver I used is com.sap.db.jdbc.driver. I got all the  837,010 rows from HANA to KNIME.The total number is right.

4

Hi,

thanks for the information and I'm happy that you like KNIME. I had a look at the implementation of the KNIME Database Reader and it uses the optional getRow() method from the JDBC ResultSet interface. If the method is not implemented KNIME uses a simple counter. I have tested the Database Reader with another db (SLlite) and a table that contains 850k rows since I do not have a HANA installation available. In this scenario the result is as expected a continuous row id. So I assume the problem is related to the HANA implementation of the getRow() method.

If you would like to have a continous RowId in KNIME you can always use the RowId node with the default settings (replace RowId with <none> as column).

Happy new year :-)

Tobias

5

Hi, Tobias

Thank you very much for your test! I reseted the connection and run the sql script again. The result is right now.So KNIME is right!

Happy New Year!