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Namit j.

2012-Sep-05 12:28 UTC

Getting error message while executing ruby code for fetchign data from MYSQL

Hi All,

I need your help on some error message that I am getting. I am working
on cucumber with selenium to automate my application.
Now I am supposed to connect to a database and fetch value from there.
Since I am new to database connectivity stuff so please excuse me for my
silly mistake if any.

Here are all the steps that I followed

1.I installed MYSQL database on my system. The version is 5.1.32.
2.Then I installed MYSQL gem. The version is mysql (2.8.1 x86-mingw32).
3.I have ruby 1.9. I do not have anything related to ROR installed on my
system.
4.I used the steps given on
http://rubylearning.com/satishtalim/ruby_activerecord_and_mysql.html
and created a database with name students.Then I created a table
rubyists in this databse.

I created the ruby file to talk to the database. The code is

require ''rubygems''
require ''active_record''
ActiveRecord::Base.establish_connection({
:adapter=> "mysql",
:host => "localhost",
:username => "root",
:password => "namitjain",
:database=> "students"

})

class Rubyist < ActiveRecord::Base
end


Rubyist.create(:name => ''Luc Juggery'', :city =>
"Nashville, Tenessee")
Rubyist.create(:name => ''Sunil Kelkar'', :city =>
"Pune, India")
Rubyist.create(:name => ''Adam Smith'', :city => "San
Fransisco, USA")

participant = Rubyist.find(:first)
puts %{#{participant.name} stays in #{participant.city}}

Rubyist.find(:first).destroy



But when I execute this file from command prompt i get the following
error:
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/mysql_adapter.rb:144:in
`each_hash'': NULL pointer given (ArgumentE
ror)
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/mysql_adapter.rb:144:in
`each_hash''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:427:in
`each''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:427:in
`map''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:427:in
`block in columns''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/mysql_adapter.rb:325:in
`execute_and_free''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:426:in
`columns''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/connection_adapters/schema_cache.rb:12:in
`block in initialize''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/model_schema.rb:228:in
`yield''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/model_schema.rb:228:in
`default''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/model_schema.rb:228:in
`columns''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/model_schema.rb:243:in
`column_defaults''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/base.rb:482:in
`initialize''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/persistence.rb:44:in
`new''
        from
C:/Ruby193/lib/ruby/gems/1.9.1/gems/activerecord-3.2.8/lib/active_record/persistence.rb:44:in
`create''
        from p080dbconnect.rb:15:in `<main>''

Please help me out and let me know if I am missing on any step that is
required for the correct step. Any input will be of great help.

Thanks in Advance,
Namit Jain

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Namit j.

2012-Sep-06 09:23 UTC

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Re: Getting error message while executing ruby code for fetchign data from MYSQL

Hi All,

I just got it working by replacing the libmySQL.dll in bin directory of 
my Ruby folder. I referred to the link 
http://fuyun.org/2010/01/ruby-mysql-adapter-on-windows/ and downloaded 
the new dll from 
http://www.dll-files.com/dllindex/dll-files.shtml?libmysql.
This might be a compatibility issue.

Thanks,
Namit

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Rails - Sep 2012 - Getting error message while executing ruby code for fetchign data from MYSQL

Getting error message while executing ruby code for fetchign data from MYSQL

Re: Getting error message while executing ruby code for fetchign data from MYSQL