我的测试平台是Ubuntu+Mono1.2.4+MySQL5+Connector/Net 5.1.4，其中Mono和MySQL都是使用apt-get方式安装很方便。MySQL Connector/Net 5.1.4从http://dev.mysql.com/downloads/connector/net/5.1.html 下载Windows Source and Binaries, no installer (ZIP)解压缩得到MySql.Data.dll。
使用gacutil -i MySql.Data.dll把MySql.Data.dll安装到Mono的全局组件目录下。
具体内容参考http://www.mono-project.com/MySQL的例子。
特别提出来的是我第一次编译运行的时候出现这样的错误提示：
MySql.Data.MySqlClient.MySqlException: Unable to connect to any of the specified MySQL hosts
in <0x006c5> MySql.Data.MySqlClient.NativeDriver:Open ()
in <0x00027> MySql.Data.MySqlClient.Driver:Create (MySql.Data.MySqlClient.MySqlConnectionString settings)
in <0x0008d> MySql.Data.MySqlClient.MySqlPool:CreateNewPooledConnection ()
in <0x001b0> MySql.Data.MySqlClient.MySqlPool:GetPooledConnection ()
in <0x0003f> MySql.Data.MySqlClient.MySqlPool:GetConnection ()
in <0x000e5> MySql.Data.MySqlClient.MySqlPoolManager:GetConnection (MySql.Data.MySqlClient.MySqlConnectionString settings)
in <0x00050> MySql.Data.MySqlClient.MySqlConnection:Open ()
不思不得其解，后来找到一个国外的论坛，得到这样的提示：
The most likely cause of this is that MySQL is not configured to accept tcp/ip connections.
See here http://dev.mysql.com/doc/mysql/en/can-not-connect-to-server.html
make
sure your /etc/mysql/my.cnf file does not have the "skip-networking"
feature enabled. This is the default in some installations and disables
tcp/ip connections.
根据提示我把my.cnf中的
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
#bind-address = 172.22.60.126
bind-address注释掉，然后重新启动mysql服务器程序sudo /etc/init.d/mysql restart就可以正常连接查询了。
GOOD Luck!