1、删除mysql的命令

sudo rm /usr/local/mysql

sudo rm -rf /usr/local/mysql*

sudo rm -rf /Library/StartupItems/MySQLCOM

sudo rm -rf /Library/PreferencePanes/My*

sudo rm -rf /Library/Receipts/mysql*

sudo rm -rf /Library/Receipts/MySQL*

sudo rm -rf /var/db/receipts/com.mysql.*

2、下载mysql

https://dev.mysql.com/downloads/mysql/5.7.html#downloads

选择下载

3、安装mysql

双击安装

选择继续

选择同意

选择安装

输入密码，选择安装

安装安装，弹出对话框，记住root密码，选择OK，安装成功，选择关闭

4、启动mysql

从launchpad中启动偏好设置

选择点击mysql

启动mysql

5、登入mysql

1）从launchpad中启动终端

执行sudo su，输入密码

使用vi .bash_profile编辑环境环境变量

export MYSQL_HOME=/usr/local/mysql/

export PATH=$PATH:$MYSQL_HOME/bin

使用source .bash_profile命令立即生效环境变量

（2）使用命令登入密码不对：

sh-3.2# mysql -uroot -p

Enter password:

ERROR 1045(28000): Access denied for user 'root'@'localhost'(using password: YES)

3）设置不需要密码登入

sudo cp /usr/local/mysql/support-files/my-small.cnf /etc/my.cnf

发现并没有/usr/local/mysql/support-files/my-small.cnf这个文件。

我们自己使用vi /ect/my.cnf创建文件 下面是创建的文件内容。

#skip-grant-tables将注释去掉。

[client]

port = 3306

default-character-set=utf8mb4

socket=/tmp/mysql.sock

[mysql]

port = 3306

default-character-set=utf8mb4

socket=/tmp/mysql.sock

[mysqld]

##########################

# summary

##########################

bind-address = 0.0.0.0

port = 3306

basedir=/usr/local/mysql

datadir=/data/mysql

socket=/tmp/mysql.sock

tmpdir = /tmp

pid-file=/tmp/mysqld.pid

#skip-grant-tables

#skip-networking

explicit_defaults_for_timestamp=1

lower_case_table_names=1

table_open_cache = 8000

##########################

# time out

##########################

connect_timeout = 20

wait_timeout = 86400

##########################

# connection

##########################

max_connections = 2000

max_user_connections = 1900

max_connect_errors = 100000

max_allowed_packet = 1G

##########################

# character set

##########################

character-set-server = utf8mb4

collation-server = utf8mb4_bin

##########################

# log bin

##########################

server-id = 1

log_bin = mysql-bin

# ROW、STATEMENT、MIXED

binlog_format = row

sync_binlog = 1

expire_logs_days = 7

binlog_cache_size = 128m

max_binlog_cache_size = 512m

max_binlog_size = 256M

master_info_repository=TABLE

relay_log_info_repository=TABLE

log_slave_updates=ON

binlog_checksum=none

binlog_ignore_db=mysql

binlog_ignore_db=information_schema

binlog_ignore_db=performation_schema

binlog_ignore_db=sys

##########################

# gtid

##########################

gtid_mode = on

enforce_gtid_consistency = on

##########################

# log relay

##########################

relay_log = mysql-relay-bin

relay_log_purge = on

relay_log_recovery = on

max_relay_log_size = 1G

##########################

# log error

##########################

log_error=/data/mysql/mysqld_error.log

##########################

# log slow

##########################

slow_query_log = on

slow_query_log_file = /data/mysql/mysqld_slow.log

long_query_time = 2

log_queries_not_using_indexes = on

##########################

# log general

##########################

general_log = on

general_log_file = /data/mysql/mysqld_gener.log

##########################

# thread pool

##########################

#thread_handling=pool-of-threads

#thread_handling=one-thread-per-connection

#thread_pool_oversubscribe=8

##########################

# innodb

##########################

innodb_file_per_table=1

innodb_log_file_size=1024M

innodb_log_buffer_size=64M

##########################

# password policy

# after init

##########################

#validate_password_length=4       

#validate_password_mixed_case_count=0

#validate_password_number_count=0

#validate_password_policy=0

#validate_password_special_char_count=0

重启mysql

通过终端登入mysql

（4）使用sql来修改mysql root密码

use mysql;

update user  set authentication_string =password("密码")where user='root';

flush privileges;

quit;

（5）使用 mysql -uroot -p