Couldn't read from database: unknown data type

Since there is a plethora of different databases out there, each with their own data types, it is impossible to define all of them beforehand. WEKA therefore comes with setups for different databases that allow you to run experiments without any additional tuning. But if you want to read database from a different data source, then it can happen that you have to tell WEKA how to import these data types.

Here is what to do:
  • Extract the weka/experiment/DatabaseUtils.props file from either the weka.jar or weka-src.jar and place it in your home directory.
  • Finally, check out the section Missing Datatypes in the Databases article and add the missing data types accordingly.