本来根据官网的教程一步一步下来之后ubuntu 12.04下源代码安装mysql是可以的，但是在安装了python-mysqldb之后发现mysql就不行了
前几天一直在弄这个。本来根据官网的教程一步一步下来之后ubuntu 12.04下源代码安装mysql是可以的，，但是在安装了python-mysqldb之后发现mysql就不行了，已启动就会出现“the mysql server quit without updating the pid file（/usr/local/bin/mysql/data/xxxxx.pid错误或者出现”mysql server cannot be found（/usr/bin/mysqld_safe)“错误。
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ubuntu 12.04下安装mysql图解
linux源码安装mysql 5.6.12 （cmake编译）
基于cmake编译安装mysql 5.5
ubuntu 通过deb 安装 mysql 5.5
后来发现是一个/etc/mysql/my.cnf这个文件导致的，这个文件是安装了python-mysqldb之后才会出现的，除非你安装mysql是把my-default.cnf拷贝到这个位置了。安装好后python-mysqldb之后的/etc/mysql/my.cnf文件的内容应该如下:
#
# the mysql database server configuration file.
#
# you can copy this to one of:
# - /etc/mysql/my.cnf to set global options,
# - ~/.my.cnf to set user-specific options.
#
# one can use all long options that the program supports.
# run program with --help to get a list of available options and with
# --print-defaults to see which it would actually understand and use.
#
# for explanations see
#
# this will be passed to all mysql clients
# it has been reported that passwords should be enclosed with ticks/quotes
# escpecially if they contain # chars...
# remember to edit /etc/mysql/debian.cnf when changing the socket location.
[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock
# here is entries for some specific programs
# the following values assume you have at least 32m ram
# this was formally known as [safe_mysqld]. both versions are currently parsed.
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
#
# * basic settings
#
user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking
#
# instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
bind-address = 127.0.0.1
#
# * fine tuning
#
key_buffer = 16m
max_allowed_packet = 16m
thread_stack = 192k
thread_cache_size = 8
# this replaces the startup script and checks myisam tables if needed
# the first time they are touched
myisam-recover = backup
#max_connections = 100
#table_cache = 64
#thread_concurrency = 10
#
# * query cache configuration
#
query_cache_limit = 1m
query_cache_size = 16m
#
# * logging and replication
#
# both location gets rotated by the cronjob.
# be aware that this log type is a performance killer.
# as of 5.1 you can enable the log at runtime!
#general_log_file = /var/log/mysql/mysql.log
#general_log = 1
#
# error log - should be very few entries.
#
log_error = /var/log/mysql/error.log
#
# here you can see queries with especially long duration
#log_slow_queries = /var/log/mysql/mysql-slow.log
#long_query_time = 2
#log-queries-not-using-indexes
#
# the following can be used as easy to replay backup logs or for replication.
# note: if you are setting up a replication slave, see readme.debian about
# other settings you may need to change.
#server-id = 1
#log_bin = /var/log/mysql/mysql-bin.log
expire_logs_days = 10
max_binlog_size = 100m
#binlog_do_db = include_database_name
#binlog_ignore_db = include_database_name
#
# * innodb
#
# innodb is enabled by default with a 10mb datafile in /var/lib/mysql/.
# read the manual for more innodb related options. there are many!
#
# * security features
#
# read the manual, too, if you want chroot!
# chroot = /var/lib/mysql/
#
# for generating ssl certificates i recommend the openssl gui tinyca.
#
# ssl-ca=/etc/mysql/cacert.pem
# ssl-cert=/etc/mysql/server-cert.pem
# ssl-key=/etc/mysql/server-key.pem
[mysqldump]
quick
quote-names
max_allowed_packet = 16m
[mysql]
#no-auto-rehash # faster start of mysql but no tab completition
[isamchk]
key_buffer = 16m