Activerecord::JDBCError: Invalid column number

rubyonrails-talk
1

Hi,

I'm rather new to Ruby and RoR, so I do not really know whether this ist the right forum to place my question.

For my first 'project' I planned to create a simple online-viewer, which grabs data from an existing database and make them visible in a structured form via browsers. So I thought that could be the right beginner-project, because I have only read datasets without any editing or creating.

The existing database is a very old one (Pervasive 8.7) and the db-design is poor, but that is all I have and I have to live with it.

Fortunately there are JDBC-Drivers, so a connection via activerecord-jdbc-adapter will work... I thought.

Within the services of Netbeans using those JDBC-Drivers I'm able to establish a connection to the database and the IDE shows me all available tables and there referring datasets.

The content of database.yml is only:

development:   adapter: jdbc   username:   password:   driver: com.pervasive.jdbc.v2.Driver   url: jdbc:pervasive://192.168.0.130:1583/database

No test-db and no production-db, because the development-db is read-only.

After putting these tow lines into the environment.rb:

$CLASSPATH << "file:///#{Rails.root}/lib/java/pvjdbc2.jar" $CLASSPATH << "file:///#{Rails.root}/lib/java/pvjdbc2x.jar"

the application started with webrick gives no error-message, so I think, that the JDBC-drivers are loaded correctly.

Now I made a model mandate_file.rb which contains

class MandateFile < ActiveRecord::Base

  # fix non-standard table and primary key name conventions   set_table_name "STAMM"   set_primary_key :D_LFDNR

  # fix the upper-cased named columns         alias_attribute :id, :D_LFDNR   alias_attribute :annotext_az, :D_AZ   alias_attribute :name_creditor, :D_RUBGE

end

When I try to create a simple object via the console using "m = MandateFile.new" I get the following list of errors:

ActiveRecord::JDBCError: Invalid column number         from arjdbc/jdbc/RubyJdbcConnection.java:121:in `columns'         from c:/jruby/lib/ruby/gems/1.8/gems/activerecord-jdbc-adapter-1.1.1/lib/arjdbc/jdbc/adapter.rb:229:in `jdbc_columns'         from c:/jruby/lib/ruby/gems/1.8/gems/activerecord-3.0.7/lib/active_record/base.rb:680:in `columns'         from c:/jruby/lib/ruby/gems/1.8/gems/activerecord-3.0.7/lib/active_record/persistence.rb:284:in `attributes_from_column_definition'         from c:/jruby/lib/ruby/gems/1.8/gems/activerecord-3.0.7/lib/active_record/locking/optimistic.rb:62:in `attributes_from_column_definition'         from c:/jruby/lib/ruby/gems/1.8/gems/activerecord-3.0.7/lib/active_record/base.rb:1395:in `initialize'         from (irb):1:in `evaluate'         from org/jruby/RubyKernel.java:1088:in `eval'         from C:/jruby/lib/ruby/1.8/irb.rb:158:in `eval_input'         from C:/jruby/lib/ruby/1.8/irb.rb:271:in `signal_status'         from C:/jruby/lib/ruby/1.8/irb.rb:155:in `eval_input'         from org/jruby/RubyKernel.java:1418:in `loop'         from org/jruby/RubyKernel.java:1191:in `catch'         from C:/jruby/lib/ruby/1.8/irb.rb:154:in `eval_input'         from C:/jruby/lib/ruby/1.8/irb.rb:71:in `start'         from org/jruby/RubyKernel.java:1191:in `catch'         from C:/jruby/lib/ruby/1.8/irb.rb:70:in `start'         from c:/jruby/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands/console.rb:44:in `start'         from c:/jruby/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands/console.rb:8:in `start'         from c:/jruby/lib/ruby/gems/1.8/gems/railties-3.0.7/lib/rails/commands.rb:23:in `(root)'         from org/jruby/RubyKernel.java:1038:in `require'         from script\rails:6:in `(root)

I've googled for 'Invalid column number' but found nothing, what might be helpful.

I think, that I make a very simple mistake, but I've no idea about it. Are there any hints for me?

Thanks in advance!

Klaus

2

Hi,

I'm rather new to Ruby and RoR, so I do not really know whether this ist the right forum to place my question.

For my first 'project' I planned to create a simple online-viewer, which grabs data from an existing database and make them visible in a structured form via browsers. So I thought that could be the right beginner-project, because I have only read datasets without any editing or creating.

The existing database is a very old one (Pervasive 8.7) and the db-design is poor, but that is all I have and I have to live with it.

Fortunately there are JDBC-Drivers, so a connection via activerecord-jdbc-adapter will work... I thought.

Within the services of Netbeans using those JDBC-Drivers I'm able to establish a connection to the database and the IDE shows me all available tables and there referring datasets.

The content of database.yml is only:

development: adapter: jdbc username: password: driver: com.pervasive.jdbc.v2.Driver url: jdbc:pervasive://192.168.0.130:1583/database

No test-db and no production-db, because the development-db is read-only.

Check to make sure your columns in your model are correctly listed. It sounds like it is trying to use the id column or numerically increment a column that is not numeric.

Also, if the database is read only then MandateFile.new is not going to work anyway since you won't be able to save the record.

B.

3

Okay, I've choesen an other table with only 11 columns and listed them all:

class MandateFile < ActiveRecord::Base

  # fix non-standard table and primary key name conventions   set_table_name :AZLOELOG   set_primary_key :D_AZLOGNR

  alias_attribute :id, :D_AZLOGNR   alias_attribute :annotext_az, :D_AZLOAGAZ   alias_attribute :name_debtor, :D_AZLOGRUB1   alias_attribute :name_creditor, :D_AZLOGRUB2   alias_attribute :delete_date, :D_AZLOGDAT   alias_attribute :delete_user, :D_AZLOGUSER   alias_attribute :not_used, :D_AZLOGFREE   alias_attribute :log_sign, :D_AZLOGKE   alias_attribute :delete_year, :D_AZLOGAZJAHR   alias_attribute :delete_counter, :D_AZLOGAZZAEHL   alias_attribute :reserved, :D_AZLOGRES

end

I've also switched the database access to 'read+write'. Column's D_AZLOGNR datatype is integer. IMHO I did and checked all that Bryan told me, but the result is the same: ActiveRecord::JDBCError: Invalid column number

Any mory suggestions?

4

Do you get the same behavior if you just call 'MandateFile.columns'? I suspect you will - this sounds like an issue with the JDBC driver rather than your code. You might want to try the AR-JDBC JIRA and/or mailing lists:

http://kenai.com/jira/browse/ACTIVERECORD_JDBC

--Matt Jones

5

Matt Jones wrote in post #997376:

Do you get the same behavior if you just call 'MandateFile.columns'?

Hi Matt,

MandateFile.columns quits with

RuntimeError: The driver encountered an unknown error: java.lang.NullPointerException: null

I suspect you will - this sounds like an issue with the JDBC driver rather than your code.

Maybe, but if its so, it must be in addition to activerecord, because I used the same JDBC driver several months ago to establish a connection through pure Java and I was able to query the database via simple SQL-Statements.

You might want to try the AR-JDBC JIRA and/or mailing lists:

http://kenai.com/jira/browse/ACTIVERECORD_JDBC

Thanks, I will take a look at these.

Greetings

Klaus