24Jul/092
Careful with those required files in Ruby
Getting Ruby to talk to MySQL was pretty easy in irb:
C:\>irb
irb(main):001:0> require 'rubygems'
=> true
irb(main):002:0> require 'mysql'
=> true
irb(main):003:0> db = Mysql.connect('localhost', 'root', 'password', 'test')
=> #<Mysql:0x2cc5270>
irb(main):004:0>
But then I tried the very same code from a file:
C:\>ruby mysql.rb
./mysql.rb:3: uninitialized constant Mysql (NameError)
from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
from C:/Ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
from mysql.rb:2
That require 'mysql' line looks in the current directory first ... and I'd used the name mysql.rb for the file I was coding ... so my code just included itself, and not the gem I wanted. Doh!
July 24th, 2009 - 15:11
I’ve been bit by something similar in Python. Calling it mysql.py, and then trying to import a “real” mysql module elsewhere. :)
July 7th, 2010 - 08:48
wow… I did exactly the same thing. Doh! is right.
Thanks for the tip.