no such file to load -- mysql

也有多种情况罗列到一起吧

# MySQL. Versions 4.1 and 5.0 are recommended. 
# 
# Install the MySQL driver: 
# gem install mysql 
# On Mac OS X: 
# sudo gem install mysql -- --with-mysql-dir=/usr/local/mysql 
# On Mac OS X Leopard: 
# sudo env ARCHFLAGS="-arch i386" gem install mysql -- --with-mysql－config=/usr/local/mysql/bin/mysql_config 

sudo env ARCHFLAGS="-arch i386" gem install mysql -- --with-mysql-dir=/usr/local/mysql --with-mysql-lib=/usr/local/mysql/lib --with-mysql-include=/usr/local/mysql/include

一下为linux情况

You may face some issues while configuring rails;

引用

no such file to load — mysql
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require’
/usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’
/usr/lib/ruby/gems/1.8/gems/activesupport-2.3.2/lib/active_support/dependencies.rb:156:in `require’
/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/mysql_adapter.rb:65:in `mysql_connection’
and so on

step 1:
If you havn’t done “

gem install mysql

”; do it first.

step 2:

引用

If it doesn’t work even after “gem install mysql”; search for “mysql.so” in your system. In linux box; the path would be something like;
‘/usr/local/lib/ruby/gems/1.8/gems/mysql-2.7/mysql.so’

step 3:
In the error message; you will see the error file(mysql_adapter.rb); In my case it is [check error sample above];

引用

/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/mysql_adapter.rb:65:in `mysql_connection’

step 4:
Open the file “/usr/lib/ruby/gems/1.8/gems/activerecord-2.3.2/lib/active_record/connection_adapters/mysql_adapter.rb” and go to location 65.

You will find a line something like;

require_library_or_gem(’mysql’)

change this line to look like;

require_library_or_gem(’/usr/local/lib/ruby/gems/1.8/gems/mysql-2.7/mysql.so’)


再不行参考如下
http://www.ruby-forum.com/topic/192550