总结关于Mac上使用MySQL一些常见的问题

Num 1.  MySQL5.7导出数据时提示--secure-file-priv解决办法：

问题分析

　　在官方的文档中，对secure_file_priv进行了说明，它用于限制数据的导出。　　

1. secure_file_priv 为 NULL 时，表示限制mysqld不允许导入或导出。
2. secure_file_priv 为 /tmp 时，表示限制mysqld只能在/tmp目录中执行导入导出，其他目录不能执行。
3. secure_file_priv 没有值时，表示不限制mysqld在任意目录的导入导出。

　　在Mysql中输入命令show variables like '%secure_file_priv%';可以看到默认secure_file_priv = NULL。

　　mysql> show global variables like '%secure_file_priv%';
　　+------------------+-------+
　　| Variable_name    | Value |
　　+------------------+-------+
　　| secure_file_priv | NULL  |
　　+------------------+-------+

 解决办法

　　1. 检查support-files文件夹（路径 /usr/local/mysql/support-files  这是Mac中的隐藏文件夹，在Finder下shift+command+g然后输入路径），是否有my.cnf配置文件，在Mac中好像是默认不存在该文件（具体不清楚），需要我们自己手动配置Mysql。

　　2. （关闭Mysql）需要在 /etc下配置my.cnf，首先 cd /etc，然后手动配置，vim my.cnf，输入以下配置信息。

  # Example MySQL config file for medium systems.
  #
  # This is for a system with little memory (32M - 64M) where MySQL plays
  # an important part, or systems up to 128M where MySQL is used together with
  # other programs (such as a web server)
  #
  # MySQL programs look for option files in a set of
  # locations which depend on the deployment platform.
  # You can copy this option file to one of those
  # locations. For information about these locations, see:
  # http://dev.mysql.com/doc/mysql/en/option-files.html
  #
  # In this file, you can use all long options that a program supports.
  # If you want to know which options a program supports, run the program
  # with the "--help" option.
  # The following options will be passed to all MySQL clients
  [client]
  default-character-set=utf8
  #password   = your_password
  port        = 3306
  socket      = /tmp/mysql.sock
  # Here follows entries for some specific programs
  # The MySQL server
[mysqld]
  character-set-server=utf8
  init_connect='SET NAMES utf8
  port        = 3306
  socket      = /tmp/mysql.sock
  skip-external-locking
  key_buffer_size = 16M
  max_allowed_packet = 1M
  table_open_cache = 64
  sort_buffer_size = 512K
  net_buffer_length = 8K
  read_buffer_size = 256K
  read_rnd_buffer_size = 512K
  myisam_sort_buffer_size = 8M
  character-set-server=utf8
  init_connect='SET NAMES utf8'
  secure_file_priv=
# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
#
#skip-networking

  # Replication Master Server (default)
  # binary logging is required for replication
  log-bin=mysql-bin

    # binary logging format - mixed recommended
    binlog_format=mixed

      # required unique id between 1 and 2^32 - 1
      # defaults to 1 if master-host is not set
      # but will not function as a master if omitted
      server-id   = 1
    # Replication Slave (comment out master section to use this)
    #
    # To configure this host as a replication slave, you can choose between
    # two methods :
    #
    # 1) Use the CHANGE MASTER TO command (fully described in our manual) -
    #    the syntax is:
    #
    #    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
    #    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
    #
    #    where you replace <host>, <user>, <password> by quoted strings and
    #    <port> by the master's port number (3306 by default).
    #
    #    Example:
    #
    #    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
    #    MASTER_USER='joe', MASTER_PASSWORD='secret';
    #
    # OR
    #
    # 2) Set the variables below. However, in case you choose this method, then
    #    start replication for the first time (even unsuccessfully, for example
    #    if you mistyped the password in master-password and the slave fails to
    #    connect), the slave will create a master.info file, and any later
    #    change in this file to the variables' values below will be ignored and
    #    overridden by the content of the master.info file, unless you shutdown
    #    the slave server, delete master.info and restart the slaver server.
    #    For that reason, you may want to leave the lines below untouched
    #    (commented) and instead use CHANGE MASTER TO (see above)
    #
    # required unique id between 2 and 2^32 - 1
    # (and different from the master)
    # defaults to 2 if master-host is set
    # but will not function as a slave if omitted
    #server-id       = 2
    #
    # The replication master for this slave - required
    #master-host     =   <hostname>
    #
    # The username the slave will use for authentication when connecting
    # to the master - required
    #master-user     =   <username>
    #
    # The password the slave will authenticate with when connecting to
    # the master - required
    #master-password =   <password>
    #
    # The port the master is listening on.
    # optional - defaults to 3306
    #master-port     =  <port>
    #
    # binary logging - not required for slaves, but recommended
    #log-bin=mysql-bin

      # Uncomment the following if you are using InnoDB tables
      #innodb_data_home_dir = /usr/local/mysql/data
      #innodb_data_file_path = ibdata1:10M:autoextend
      #innodb_log_group_home_dir = /usr/local/mysql/data
      # You can set .._buffer_pool_size up to 50 - 80 %
      # of RAM but beware of setting memory usage too high
      #innodb_buffer_pool_size = 16M
      #innodb_additional_mem_pool_size = 2M
      # Set .._log_file_size to 25 % of buffer pool size
      #innodb_log_file_size = 5M
      #innodb_log_buffer_size = 8M
      #innodb_flush_log_at_trx_commit = 1
      #innodb_lock_wait_timeout = 50

        [mysqldump]
        quick
        max_allowed_packet = 16M
          [mysql]
          no-auto-rehash
          # Remove the next comment character if you are not familiar with SQL
          #safe-updates
          default-character-set=utf8

        [myisamchk]
        key_buffer_size = 20M
        sort_buffer_size = 20M
        read_buffer = 2M
        write_buffer = 2M

          [mysqlhotcopy]
          interactive-timeout

　　3. sudo chmod 644 my.cnf，将该配置文件的读写执行权限改为644。（推荐每次修改该配置文件后都重新设置644权限）

　　4. 打开Mysql，输入 show variables like '%secure_file_priv%';可以看到secure_file_priv = 空。

　　mysql> show variables like '%secure_file_priv%';
　　+------------------+-------+
　　| Variable_name    | Value |
　　+------------------+-------+
　　| secure_file_priv |       |
　　+------------------+-------+
　　1 row in set (0.00 sec)

Num2. MySQL导入数据显示“Error code:13. Can't get stat of ‘  ’（Permission denied）”解决办法：　

解决办法：

　　　　在解决"secure-file-priv"问题后，导入数据时再次碰见错误。在google后找到解决办法。

　　　　  将load data infile 改为 load data local infile。错误即可解决（具体原因不清楚）

Num3. MySQL导出数据显示“Can't create/write to file ‘Users/***’（Errcode:13）”解决办法：

问题分析：

　　　　这应该是关于MySQL临时文件目录的问题，为解决这个问题做了很多尝试，在my.cnf配置临时文件目录，并给予该文件777权限等等都没有解决问题。

解决办法：

　　　　最后同样在google上找到解决办法。如下图

　　　　这是由于权限问题，因为试图让mysql用户将数据写入私人主目录。我们可以在usr/local下创建一个文件夹，用来保存从mysql中导出的数据。

2019-06-30 18:03:14　

Num4. 关于MySQL5.7下初始密码

问题分析：

　　　　安装Mysql5.7完成后，Mysql会随机给定一个初始密码。

 

Num5. MySQL启动出现“MySQL server PID file could not be found!

Starting MySQL...The server quit without updating PID file (/usr/local/mysql/data/rekfan.pid).”解决办法

问题分析：

　　　　比较详细的分析见https://blog.csdn.net/zalion/article/details/9274263

解决办法：

　　　　就我自己的尝试而言，以下三种情况可能性较大

　　 1.可能是/usr/local/mysql/data/rekfan.pid文件没有写的权限

解决方法 ：给予权限，执行 “chown -R mysql:mysql /var/data” “chmod -R 755 /usr/local/mysql/data”  然后重新启动mysqld

　　 2.  可能进程里已经存在mysql进程

解决方法：用命令“ps -ef|grep mysqld”查看是否有mysqld进程，如果有使用“kill -9  进程号”杀死，貌似在最后还会剩下一个进程，mysqld。

　　 3.  mysql在启动时没有指定配置文件时会使用/etc/my.cnf配置文件，请打开这个文件查看在[mysqld]节下有没有指定数据目录(datadir)

　　　  解决方法：请在[mysqld]下设置这一行：datadir = /usr/local/mysql/data。希望用Mac的同学，安装好Mac之后就配置好my.cnf（新建位于/etc/下）

2019-07-08 18:33:25 更新