A face this time to time. I join two tables where number columns a should join on are of different sizes. For instance, I could have Long value on the left and Int value on the right. I would believe I can always state the values equal or differ no matter how many bites each value occupies in memory.
But every time I was joining two tables using a pair of long and int column, I got an error: " Type mismatch found of Joining Column Pair “x” and “y”.This causes an empty output table."
Definitely +1 on the issue. This happens to me, where I’ll receive a .csv file from another department where the customer ID information is stored as a string. When I join it with data that’s pulled from our table (stored as integer), I get the error you’re experiencing. It’s not a big deal, but it is annoying, especially if you’re working with a large workflow and end up having to convert several times throughout.
It would be great either to have a checkbox that converts all joining columns to strings, or to have a checkbox that converts formats on the “left” table to formats on the “right” table (or vice versa).
Thanks for your contribution. I’d be careful with the case you replied with. What I suggested it should be possible to join tables on integer number columns with no respect to their size (integer, long, …). I don’t think we can apply this to joins on string and number columns each other safely too. At least it would take some performance costs if the node converted all values to string to perform the join.
with KNIME version 4.4.0 Joiner node is now out of Labs and features a possibility to match different column types. Give it a try and feel free to comment.