Mac 的mysql5.7没有配置文件，如何解决only_full_group_by 问题

数据库版本是5.7.19，在写语句的时候，只要涉及ORDER BY,就会报错，

ERROR 1055 (42000): Expression #7 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'postscan.verifyDelayLog.auditor' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by

这个时候，百度发现，是因为这个版本的mysql 数据库默认开启了 sql_mode 字段的only_full_group_by 属性。这个属性是在你写语句时，当你 ORDER BY 的字段不在select 的字段当中，都会报错。

sql_mode 属性是在mysql数据库，event表中，

点进去，可以看到默认属性是

ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

解决这个问题，就需要修改这个字段的属性。

方法一
在navicat 里面直接针对event表进行修改

set GLOBAL sql_mode ='STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION ';

这样就能去掉only_full_group_by 字段。但弊端是这个方法是针对session的，也就是说每次连接mysql 前，都需要set一次。

方法二
修改配置mysql的文件
mac在安装这个版本的mysql的时候，我没有发现mysql 的配置文件。不管是
/etc 下还是 mysql 的support-files 下都没有

这个时候，可以自己在etc目录下创建一个

关闭mysql

sudo vim /etc/my.cnf

然后往文件里写这个配置就ok。

# 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
  sql_mode='NO_AUTO_VALUE_ON_ZERO,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION,PIPES_AS_CONCAT,ANSI_QUOTES'
  init_connect='SET NAMES utf8'
# 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