mysql常用操作

root用户登录mysql

mysql -u root -p

创建用户

create user 'yuzhiyun'@'%' identified by '1234';

由于在使用navicate远程访问数据库使用root用户不太安全，所以应该新建用户，然后授予权限，只让该用户访问一个数据库，达到安全目的。

root下给某个用户授与所有权限

grant all privileges  on *.* to yuzhiyun@'%' identified by '1234';

. 表示所有数据库，@’%’表示所有终端，如果是localhost就不能远程访问

查看所有用户

select * from mysql.user;

查看编码

show variables like "character%";

出现下图就说明编码修改是正确的，全部是utf8了

修改编码

如果不是如图所示，而是ltin1编码，就要修改编码，在ubuntu下修改编码是修改etc/mysql/my.cnf文件，
1、在[client]下添加default-character-set=utf8
2、在[mysqld]下添加character_set_server=utf8
具体my.cnf内容示例：

## 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# http://dev.mysql.com/doc/mysql/en/server-system-variables.html# 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        = 3306socket      = /var/run/mysqld/mysqld.sockdefault-character-set=utf8# 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.socknice        = 0[mysqld]## * Basic Settings#user        = mysqlpid-file    = /var/run/mysqld/mysqld.pidsocket      = /var/run/mysqld/mysqld.sockport        = 3306basedir     = /usrdatadir     = /var/lib/mysqltmpdir      = /tmplc-messages-dir = /usr/share/mysqlskip-external-lockingcharacter_set_server=utf8max_connections=1000## Instead of skip-networking the default is now to listen only on# localhost which is more compatible and is not less securitybind-address        = 0.0.0.0## * Fine Tuning#key_buffer      = 16Mmax_allowed_packet  = 16Mthread_stack        = 192Kthread_cache_size       = 8# This replaces the startup script and checks MyISAM tables if needed# the first time they are touchedmyisam-recover         = BACKUP#max_connections        = 100#table_cache            = 64#thread_concurrency     = 10## * Query Cache Configuration#query_cache_limit   = 1Mquery_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.logexpire_logs_days    = 10max_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]quickquote-namesmax_allowed_packet  = 16M[mysql]#no-auto-rehash # faster start of mysql but no tab completition[isamchk]key_buffer      = 16M## * IMPORTANT: Additional settings that can override those from this file!#   The files must end with '.cnf', otherwise they'll be ignored.#!includedir /etc/mysql/conf.d/

navicate 远程连接数据库报错 2003 cannot connect mysql server 10038

错误原因很多种，举例：
1、服务未开启
2、数据库用户权限不够，要授权该用户可以远程访问
3、该数据库只可以在本机被访问（也就是在my.cnf文件中有这一句话：bind-address = 127.0.0.1）

但是在我这里发生错误的原因是第三种，没有修改my.cnf,
设置允许所有ip地址访问该数据库，
vim /etc/MySQL/my.cnf
找到bind-address = 127.0.0.1
注释掉这行，如：#bind-address = 127.0.0.1
或者改为： bind-address = 0.0.0.0
允许任意IP访问；
或者自己指定一个IP地址。

ubuntu启动mysql服务

~$ sudo service mysql start

ubuntu下千万别忘记sudo，windows下cmd是不需要sudo的，直接就是service mysql start

修改密码

比如需要把root的密码从1234改成5670

mysqladmin -u root -p1234 password 5670

注意，-p1234是没有空格的，mysqladmin 也没有。
然后注意重启mysql ，先sudo mysql stop 再sudo mysql start.不重启的话，navicate 的那个连接仍旧可以使用，重启后，连接就失效了，必须重新新建连接才能连接到数据库。