oracle網站下載mysql(5.7)的壓縮檔案並解壓。
要初始化資料目錄，呼叫 mysqld的與 - -initialize或 - -initialize不安全的選項，這取決於你是否希望伺服器生成的一個隨機初始密碼’root’@’本地賬號’的賬戶，data目錄下生成一個以err結尾的檔案，裡面有[email protected]的臨時的密碼：。
windows下使用mysqld - -initialize或者mysqld - -initialize-insecure
windows下使用mysqld - -initialize，會生成一個臨時的密碼，可以通過 伺服器管理器 診斷 事件檢視器 windows日誌 應用程式 檢視mysql的日誌資訊：

在Unix和類Unix系統，重要的是要確保資料庫的目錄和檔案都是由擁有 MySQL的登入帳戶，以便伺服器具有讀寫訪問它們，當你以後執行它。為了確保這一點，如果你執行的mysqld為root，包括 –user選項，如下所示：

 shell> bin/mysqld --initialize --user=mysql
 shell> bin/mysqld --initialize-insecure --user=mysql

2018-03-19T02:14:39.680642Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is
 
 deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-03-19T02:14:40.367043Z 0 [Warning] InnoDB: New log files created, LSN=45790
2018-03-19T02:14:40.491843Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-03-19T02:14:40.507444Z 0 [Warning] No existing UUID has
 
 been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 47e670bc-2b1b-11e8-bd1b-005056bbabb6.
2018-03-19T02:14:40.523044Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2018-03-19T02:14:44.766251Z 0 [Warning] CA certificate ca.pem is self signed.
2018-03-19T02:14:45.593052Z 1 [Note] A temporary password is generated for [email protected]: IYers=hp(0hC   // 此處是root使用者的臨時密碼資訊。
2018-03-19T02:15:49.802765Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-03-19T02:15:49.802765Z 0 [Note] --secure-file-priv is set to NULL. Operations related to importing and exporting data are disabled
2018-03-19T02:15:49.802765Z 0 [Note] MySQL (mysqld 5.7.21-enterprise-commercial-advanced) starting as process 213416 ...
2018-03-19T02:15:49.802765Z 0 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions
2018-03-19T02:15:49.802765Z 0 [Note] InnoDB: Uses event mutexes
2018-03-19T02:15:49.802765Z 0 [Note] InnoDB: _mm_lfence() and _mm_sfence() are used for memory barrier
2018-03-19T02:15:49.818365Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.3
2018-03-19T02:15:49.818365Z 0 [Note] InnoDB: Number of pools: 1
2018-03-19T02:15:49.818365Z 0 [Note] InnoDB: Not using CPU crc32 instructions
2018-03-19T02:15:49.818365Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2018-03-19T02:15:49.833965Z 0 [Note] InnoDB: Completed initialization of buffer pool
2018-03-19T02:15:49.849565Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2018-03-19T02:15:49.943165Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2018-03-19T02:15:49.943165Z 0 [Note] InnoDB: Setting file '.\ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2018-03-19T02:15:49.989966Z 0 [Note] InnoDB: File '.\ibtmp1' size is now 12 MB.
2018-03-19T02:15:49.989966Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2018-03-19T02:15:49.989966Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2018-03-19T02:15:49.989966Z 0 [Note] InnoDB: Waiting for purge to start
2018-03-19T02:15:50.052366Z 0 [Note] InnoDB: 5.7.21 started; log sequence number 2551175

初始化後，執行：mysqld MySQL啟動mysql服務。
登入

mysql -hlocalhost -u root -p
Enter password:******

登入後：

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 5.7.21-enterprise-commercial-advanced

Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>                                                                                                                                                                    

檢視資料庫：

mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.
mysql>

提示修改mysql密碼：

alter user 'root'@'localhost' identified by 'abc23';
或者：
set password for [email protected] = password('abc23');
也可以：
SET PASSWORD FOR 'root'@'host_name' = PASSWORD('newpwd');
SET PASSWORD FOR 'root'@'%' = PASSWORD('newpwd');

用伺服器主機名替換第二個SET PASSWORD語句中的host_name。這是你指定匿名賬戶密碼的主機名。
要想使用mysqladmin為root賬戶指定密碼，執行下面的命令：
  shell> mysqladmin -u root password "newpwd"
  shell> mysqladmin -u root -h host_name password "newpwd"
  上述命令適用於Windows和Unix。用伺服器主機名替換第二個命令中的host_name。
  不一定需要將密碼用雙引號引起來，但是你如果密碼中包含空格或專用於命令解釋的其它字元，

密碼修改方式：
方法1、
update user set password=PASSWORD("123456")where user="root"; #更改密碼為 newpassord
mysql>flush privileges; #更新許可權
方法2、
shell>service mysqld stop #停止mysql服務
shell>mysqld_safe --skip-grant-tables & #以不啟用grant-tables模式啟動mysql
shell>mysql -uroot -p #輸入命令回車進入，出現輸入密碼提示直接回車。
mysql > set password for [email protected] = password('mysqlroot');

方法3、
shell>/path/mysqladmin -u UserName -h Host password 'new_password' -p

建立資料庫：
CREATE DATABASE DBNAME DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

更改資料庫的字元編碼
ALTER DATABASE DBNAME DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci

建立使用者：

CREATE USER 'username'@'host' IDENTIFIED BY 'password';

說明：
username：你將建立的使用者名稱
host：指定該使用者在哪個主機上可以登陸，如果是本地使用者可用localhost，如果想讓該使用者可以從任意遠端主機登陸，可以使用萬用字元%
password：該使用者的登陸密碼，密碼可以為空，如果為空則該使用者可以不需要密碼登陸伺服器

CREATE USER 'test'@'localhost' IDENTIFIED BY '123456';
CREATE USER 'test'@'192.168.11.11' IDENDIFIED BY '123456';
CREATE USER 'test'@'%' IDENTIFIED BY '123456';
CREATE USER 'test'@'%' IDENTIFIED BY '';
CREATE USER 'test'@'%';

授權遠端訪問：

GRANT privileges ON databasename.tablename TO 'username'@'host'

說明:
privileges：使用者的操作許可權，如SELECT，INSERT，UPDATE等，如果要授予所的許可權則使用ALL
databasename：資料庫名
tablename：表名，如果要授予該使用者對所有資料庫和表的相應操作許可權則可用表示，如.*

GRANT SELECT, INSERT ON test.user TO 'test'@'%';
GRANT ALL ON *.* TO 'test'@'%';
GRANT ALL ON maindataplus.* TO 'test'@'%';

用以上命令授權的使用者不能給其它使用者授權,如果想讓該使用者可以授權，用以下命令:

mysql> grant all privileges on *.* to 'root'@'%' identified by '********' with grant option;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges ;
Query OK, 0 rows affected (0.00 sec)

撤銷使用者授權：

REVOKE privilege ON databasename.tablename FROM 'username'@'host';

說明:
privilege, databasename, tablename：同授權部分

REVOKE SELECT ON *.* FROM 'test'@'%';

假如你在給使用者’test’@’%’授權的時候是這樣的（或類似的）：GRANT SELECT ON test.user TO ‘test’@’%’，則在使用REVOKE SELECT ON . FROM ‘test’@’%’;命令並不能撤銷該使用者對test資料庫中user表的SELECT 操作。相反，如果授權使用的是GRANT SELECT ON . TO ‘test’@’%’;則REVOKE SELECT ON test.user FROM ‘test’@’%’;命令也不能撤銷該使用者對test資料庫中user表的Select許可權。

具體資訊可以用命令SHOW GRANTS FOR ‘test’@’%’; 檢視。

刪除使用者：

DROP USER 'username'@'host';