“Database Looping” node issue - ORA-01722: invalid number


I’m having problem with extracting data from Oracle database. When I’m using database looping node, I’m receiving error ORA-01722: invalid number.

Query is very simple, just select statement.

How can I verify which column is giving this error and may I force change data type when I am reading table from Oracle database?

Thank you!

Environment: KNIME 3.7.0 on Windows 7, 64 bit

Hi @Gajdzia,

an ORA-01722 (“invalid number”) error occurs when an attempt is made to convert a character string into a number, and the string cannot be converted into a valid number.

I assume that you want to loop over a numeric column in your database table, but there seems to be an issue converting your constraint column from the KNIME table into numeric values. Can you double check that the constraint column only contains valid numeric values?