Mysql2::Error (Access denied for user 'root'@'localhost' (using password: NO)):

问题

Just setup a new rails 3.1.3 app using mysql (mysql2 gem) on CentOS 5 server / apache / passenger... I have correctly setup a database and a user for that database and I have added the login and info into my database.yml file... I can generate stuff, and rake db:migrate ok but the "We're sorry, but something went wrong." message is being rendered in the browser and this message is showing up in my production.log file!

Started GET "/" for xx.xxx.xx.xxx at 2011-12-29 19:52:35 -0600

weird, I am not using "root" as the login info in database.yml... Any suggestions?

development:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: the_db_I_made
  pool: 5
  username: the_user_I_made
  password: the_password
  socket: /var/lib/mysql/mysql.sock

production:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  database: the_db_I_made
  pool: 5
  username: the_user_I_made
  password: the_password
  socket: /var/lib/mysql/mysql.sock

回答1:

Bunch of questions / suggestions:

Can you connect to the database using the terminal?
```
mysql -u root -p
```
Also, have you tried this on development mode? If so, please share the results.
Try removing
```
socket: /var/lib/mysql/mysql.sock
```
Is the gem installation correct?
```
gem check mysql2
```

EDIT:

There is a lot of difference in development and production mode ( including but not limited to, environment variables like the database connection string, asset pre-compilation, different level of logging, custom debug info on error pages )

** Embarrassing!!**

You have not included the "host" property in your config!

Try this:

production:
  adapter: mysql2
  encoding: utf8
  reconnect: false
  host: your_host #<----- normally localhost
  database: the_db_I_made
  pool: 5
  username: the_user_I_made
  password: the_password
  socket: /var/lib/mysql/mysql.sock

回答2:

Ok, I guess this is all part of my learning curve :)

What it ended up being was this: The gem for passenger that I installed originally was version 3.0.9, I did a gem update --system and that installed version 3.0.11. So the server thought it was using version 3.0.11 and I was still pointing to libraries for 3.0.9 in my rails_server.conf file. I found how to upgrade on http://blog.phusion.nl/

回答3:

In Ubuntu 1)/usr/bin/mysql_secure_installation 2) Run in Terminal follow the steps carefully change the mysql password here.Everything done .then go to database.yml change the password previously what u have created. Run rails server and check the application .. it will works

回答4:

Did you create the database "the_db_I_made"?

First create it, then only run it, else it will show this error continuously.

Now try to tun it.

回答5:

For Me It was giving error because of no database. So i created one Using :

$ rake db:create

And the problem was solved :D

来源：https://stackoverflow.com/questions/8675489/mysql2error-access-denied-for-user-rootlocalhost-using-password-no

标签

ruby-on-rails

mysql2