Unable to connect mysql from Sequel gem

Question

When I try to connect to MySQL from Sequel. I am getting these errors:

require 'rubygems'
        require 'sequel'
        DB = Sequel.connect(:adapter => 'mysql', :user => 'root', :host => 'localhost', :database => 'scanty',:password=>'xx')
        DB.tables
    Sequel::DatabaseConnectionError: NameError uninitialized constant Mysql::CLIENT_MULTI_RESULTS
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/adapters/mysql.rb:98:in `connect'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/database.rb:92:in `initialize'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:166:in `call'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:166:in `make_new'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:153:in `available'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:144:in `acquire'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:143:in `synchronize'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:143:in `acquire'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/connection_pool.rb:105:in `hold'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/database.rb:471:in `synchronize'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/adapters/mysql.rb:128:in `execute'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/dataset.rb:314:in `execute'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/adapters/mysql.rb:342:in `execute'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/adapters/mysql.rb:298:in `fetch_rows'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/dataset.rb:185:in `each'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/dataset/convenience.rb:156:in `map'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/dataset/convenience.rb:156:in `map'
        from /opt/local/lib/ruby/gems/1.8/gems/sequel-3.2.0/lib/sequel/adapters/shared/mysql.rb:60:in `tables'
        from (irb):6irb(main):007:0> Sequel::DatabaseConnectionError: NameErro

Seems that your error is truncated? Also, where is the host in your function call? — Artem Russakovskii, Jul 17 '09 at 17:30

score 14 · Accepted Answer · edited Mar 04 '13 at 21:19

14

You need to install the native MySQL driver, the pure ruby one is not compatible with Sequel.

Depending on your Ruby installation, just doing gem install mysql may be enough. However, if the pure Ruby mysql.rb file is already in your Ruby load path, you either need to remove it from the load path or use gem('mysql') before calling Sequel.connect.

edited Mar 04 '13 at 21:19

the Tin Man

158,662
42
215
303

answered Aug 04 '09 at 21:55

Jeremy Evans

11,959
27
26

score 1 · Answer 2 · edited Mar 04 '13 at 21:19

1

You are missing the :host=>'localhost' or whatever your host is.

Also, and this is just purely for performance reasons, you should try to enable :compress. It can save a TON of bandwidth.

http://sequel.rubyforge.org/rdoc/files/doc/opening_databases_rdoc.html

Edit: OK, if it's not the host, perhaps it's a conflict? See http://groups.google.com/group/sequel-talk/browse_thread/thread/ee39640a92351f1?pli=1. Also http://www.mail-archive.com/sequel-talk@googlegroups.com/msg02275.html

edited Mar 04 '13 at 21:19

the Tin Man

158,662
42
215
303

answered Jul 17 '09 at 17:31

Artem Russakovskii

21,516
18
92
115

thanks, I have two versions of mysql gem installed on machine. – Subba Rao Jul 17 '09 at 18:29

Unable to connect mysql from Sequel gem

2 Answers2

Linked