Error while executing operator "Read Database" with the name "Read total instances" in Java

akochsicakochsic RapidMiner Certified Analyst, Member Posts: 4 Contributor I
edited December 2018 in Help

Hello,

I am new to rapidminer and I am trying to get an old program running. It is an Java project using the rapidminer command line mode.

Since it is an older project it was developed with a rapidminer version 5.x. I tried to run it with several newer versions, which are available with maven.
While running the program throws following error:
com.rapidminer.operator.UserError: The dummy operator Read total instances (replacing null) cannot be executed. 

 

The process it self is runnable inside rapidminer studio.

I also tried playing aroung with the versioning in rapidminer studio, but with no success. 

You can find the process attached.

 

I don't know what my mistake could be. Hopefully you have an idea.

 

Thanks :)

Answers

  • sgenzersgenzer Administrator, Moderator, Employee, RapidMiner Certified Analyst, Community Manager, Member, University Professor, PM Moderator Posts: 2,959 Community Manager

    hello @akochsic - so dummy operators are created usually when you are using an operator in your process that RapidMiner does not recognize. I've not heard of "Read Total Instances" before...

     

    Scott

     

  • akochsicakochsic RapidMiner Certified Analyst, Member Posts: 4 Contributor I

    Hello @sgenzer,

    thanks for your quick reply.

    Sorry for the misunderstanding. "Read total instances" is the name of the operator "Read Database". 

     

    The operator is configured as follows:

    <operator activated="true" class="jdbc_connectors:read_database" compatibility="8.0.001" expanded="true" height="68" name="Read total instances" width="90" x="179" y="210">
    <parameter key="define_connection" value="predefined"/>
    <parameter key="connection" value="local (master)"/>
    <parameter key="database_system" value="MySQL"/>
    <parameter key="define_query" value="query"/>
    <parameter key="query" value="(SELECT `size`&#10;FROM `category_sizes`&#10;WHERE category=? LIMIT 1)&#10;UNION (SELECT 0); -- default value in case category is not in table."/>
    <parameter key="use_default_schema" value="true"/>
    <parameter key="prepare_statement" value="true"/>
    <enumeration key="parameters">
    <parameter key="parameter" value="VARCHAR.%{category}"/>
    </enumeration>
    <parameter key="datamanagement" value="double_array"/>
    <parameter key="data_management" value="auto"/>
    </operator>

    Thanks :)

  • sgenzersgenzer Administrator, Moderator, Employee, RapidMiner Certified Analyst, Community Manager, Member, University Professor, PM Moderator Posts: 2,959 Community Manager

    yes those look like parameters from an old Read Database operator. I'd look at the XML created from a new Read Database operator and xfer your settings & query. For example:

     

      <operator activated="true" class="process" compatibility="8.0.001" expanded="true" name="Process">
    <process expanded="true">
    <operator activated="true" class="jdbc_connectors:read_database" compatibility="8.0.001" expanded="true" height="68" name="Read Database" width="90" x="246" y="34">
    <parameter key="connection" value="MyCoolSQLDB"/>
    <parameter key="query" value="SELECT `bar`&#10;FROM `foo`"/>
    <enumeration key="parameters"/>
    </operator>
    <portSpacing port="source_input 1" spacing="0"/>
    <portSpacing port="sink_result 1" spacing="0"/>
    </process>
    </operator>

     

    Note you need to set up a database connection first in order to make this work.

     

    Scott

     

  • akochsicakochsic RapidMiner Certified Analyst, Member Posts: 4 Contributor I

    I tried creating a new repository with a new process and a new "Read database" operator, but I am still facing the same error. I can't really see any difference in the operator I am using and the example code you posted, since also both have the compatibility set to version 8.0.001.

     

    The process is still running perfectly in Rapidminer Studio. I am only facing the issue using Java with the Command Line Execution mode.

     

    This is the new example process I tried now:

     

    <?xml version="1.0" encoding="UTF-8"?><process version="8.0.001">
    <context>
    <input/>
    <output/>
    <macros/>
    </context>
    <operator activated="true" class="process" compatibility="8.0.001" expanded="true" name="Process">
    <parameter key="logverbosity" value="init"/>
    <parameter key="random_seed" value="2001"/>
    <parameter key="send_mail" value="never"/>
    <parameter key="notification_email" value=""/>
    <parameter key="process_duration_for_mail" value="30"/>
    <parameter key="encoding" value="SYSTEM"/>
    <process expanded="true">
    <operator activated="true" class="jdbc_connectors:read_database" compatibility="8.0.001" expanded="true" height="68" name="Read Database (2)" width="90" x="179" y="289">
    <parameter key="define_connection" value="predefined"/>
    <parameter key="connection" value="local (master)"/>
    <parameter key="database_system" value="MySQL"/>
    <parameter key="define_query" value="query"/>
    <parameter key="query" value="SELECT `s`&#10;FROM `article_categories`"/>
    <parameter key="use_default_schema" value="true"/>
    <parameter key="prepare_statement" value="false"/>
    <enumeration key="parameters"/>
    <parameter key="datamanagement" value="double_array"/>
    <parameter key="data_management" value="auto"/>
    </operator>
    <portSpacing port="source_input 1" spacing="0"/>
    <portSpacing port="sink_result 1" spacing="0"/>
    </process>
    </operator>
    </process>
  • sgenzersgenzer Administrator, Moderator, Employee, RapidMiner Certified Analyst, Community Manager, Member, University Professor, PM Moderator Posts: 2,959 Community Manager

    hmm sorry - don't know what to tell you. Just curious - why are you insisting on using the command line execution rather than setting up a RM Server?

     

    Scott

     

  • akochsicakochsic RapidMiner Certified Analyst, Member Posts: 4 Contributor I

    Since it's an rather old project, I tried setting it up without the need changing it too much. Maybe it would be a good idea to try working with an RM Server. Thanks for your help.

    I now found a way to get the old project running: I built the rapidminer.jar from the rapidminer5 repository and added it as an external jar to the project. This is obviously not a perfect solution, but a workaround. With the old rapidminer version I don't get any error messages.

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