Hello all, I've got a problem with mysql 4 in my Slack machine..
I've installed mysql in my compie, and the process is fine... But when I type mysql in shell, i found that the mysqld hasn't been run... ???? When I execute the mysqld, it prompts a while and ENDED !!!! I can't use mysql ... Please Help Me...

try:

#safe_mysqld -uroot


i think, i could be dead wrong. i remember there being something to do to get it to work.

Actually, the command for MySQL 4 would be "mysqld_safe --user=root &". However, running as root is a bad idea and should only be done for testing purposes!

I'm willing to admit I'm wrong about this, but I don't think it is a bad thing to run mysqld as root. In fact I think most daemons(ssh,ftp,sendmail....) are run as root.

Now running the mysql client as root is a bad idea as you probably have unrestricted access to everything.

There have been some vulnerabilities in MySQL in the past that would allow mysql users to get root access to the machine if the daemon was run as root. These have been resolved but I still prefer not to run the daemon as root. It's a personal thing, I guess.

Hmm. I didn't know that. Thanks for the tip. So if you don't run the daemon as root do you run it as mysql? Or as a regular user?

I run it as mysql, which is a user that only has rights to the MySQL data files.
When installing MySQL it's sometimes a bit tricky to get all the permissions right if you don't want to run it as root, but it will allow for a more secure system.

For MaMatO: If you start MySQL and all it gives you is "MySQL ended", a file called <machinename>.err is created in your MySQL data directory. This file contains the exact error messages which will allow you do diagnose the problem more accurately.
Where your data directory is located depends on the way you installed MySQL (Slackware pkg, source, MySQL binary).

Edit: One more thing: In most cases after installation you have to run an initialization script which will create the MySQL system tables and some other important things. It's called "mysql_install_db" if memory serves me. If these tables etc. are not created, you won't be able to run MySQL.

Running the daemon as root allows any mysql user with FILE privs to write a file anywhere on the machine.

Also make sure you have the correct user permissions as well after installation and setting up the db and running 'mysql_install_db' then do this:

chown -R mysql.mysql /var/run/mysql
safe_mysqld &

And see if it starts with no problems.

You can avoid doing that by doing a su mysql and then running mysql_install_db to ensure proper permissions. Then it should run just fine.

I am having similar problems. I tried some of the above and it seemed to work, but now when I issue the "show tables" command in the mysql database, I get an error that says:

can't read dir of './mysql' (Err code: 13)

I am running Slackware 9.0 and using MySQL 3.23.