"Read database bug?"

buki79
buki79 New Altair Community Member
edited November 5 in Community Q&A
Hi,

as I couldn't find any thing on the forum, I have to start a new thread.

I'm using Rapidminer 5.0.11 (MacOS) and I when I use the "read database" operator to connect to a MySQL DB, I can't see any results in the preview nor can I select any columns in a following operator. The connection works fine. When I test it in the "read database" operator it says connection successful. But no data is shown or read... :( Doesn't matter if I select "define query tablename / query".

Thanks for any hint!

Best regards,

Andi

Answers

  • SebastianLoh
    SebastianLoh New Altair Community Member
    Hi Andi,

    yes thats right. Due to some incompatabilities between the different SQL data bases, the propagation of the meta data (colum names, and value types) does not work properly (or is as expenseive as executing the statement) with the read database operator.

    We'll try to find an acceptable solution that works with every data base. For now you just have to remember the names of the columns, sorry.

    Best regards,

    Sebastian
  • buki79
    buki79 New Altair Community Member
    Hi,

    remembering the column wouldn't be the problem :) But when I try to enter a column manually, e.g. in a moving average operator I specified the attribute this way, I get the message "The attribute 'frequency' is missing in the example set. So I guess unless there is a bug fix or a workaround availabe I can't acces my database data, can I?

    Best regards,

    Andi
  • IngoRM
    IngoRM New Altair Community Member
    Hi Andi,

    did you try to just run the process regardless of the error shown in the problems tab? You have to distinguish between the potential errors shown in the problems tab and real runtime errors shown in the log tab. The potential errors can often be ignored, especially in cases where the meta data propagation fails simply because no meta data is available (like in your case).

    But don't worry: many users got the meaning of the problems tab wrong: for this reason the next update will deliver a clearer statement that those problems are potential problems and not actual errors.

    Cheers,
    Ingo
  • buki79
    buki79 New Altair Community Member
    Hi,

    yes, it works no matter what the error window says :) Thanks! BTW great application!!

    Best regards,

    Andi