[email protected] / :mysql
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

[email protected] / :mysql -u root -p
Enter password: 
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES) 出現這種問題首先停止mysql [email protected] / :/etc/init.d/mysql stop
Shutting down MySQL..                                      [確定]

然後使用mysqld_safe命令在啟動mysql，更新root賬號的密碼

--skip-grant-tables：不啟動grant-tables(授權表),跳過許可權控制。

--skip-networking ：跳過TCP/IP協議，只在本機訪問(這個選項不是必須的。可以不用)

執行命令：mysqld_safe --user=mysql --skip-grant-tables --skip-networking & :mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
[1] 15589
[email protected] / :160109 22:33:02 mysqld_safe Logging to '/var/lib/mysql/vip.err'.
160109 22:33:02 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql 以root使用者登入mysql- 執行命令：mysql -u root mysql [email protected] / :mysql -u root mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.28 MySQL Community Server (GPL)

Copyright (c) 2000, 2015, 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>  執行使用者密碼更新sql mysql> UPDATE user SET Password=PASSWORD('root') where USER='root'; Query OK, 4 rows affected (0.05 sec) Rows matched: 4  Changed: 4  Warnings: 0 mysql> 

查詢更改的記錄

mysql>select Host,User,Password,password_expired from user where user='root';
重要：新設定使用者或更改密碼後需用flush privileges重新整理MySQL的系統許可權相關表，否則會出現拒絕訪問，還有一種方法，就是重新啟動mysql伺服器，來使新設定生效。
mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) 退出mysql -- 重新登入 mysql> quit Bye
登入mysql 
執行show database;檢視mysql資料庫
這裡報錯： ERROR 1820 (HY000): You must SET PASSWORD before executing this statement 提示在執行之前必須設定PASSWORD ---執行設定密碼操作 mysql> SET PASSWORD = PASSWORD('123456'); Query OK, 0 rows affected (0.00 sec) 建立我們的mysql 庫 bigdata; 使用測試資料庫 建立表：
查詢剛剛插入的資料 -=============下面是官網提供的文件================

2.5.5 Installing MySQL on Linux Using RPM Packages

Note

To install or upgrade to MySQL 5.6.11 or later, be sure to read the special instructions at the end of this section.

The recommended way to install MySQL on RPM-based Linux distributions that use glibc is by using the RPM packages provided by Oracle. There are two sources for obtaining the Community versions of the RPM packages:

• From the MySQL software repositories, for the following platforms:

• From the MySQL Downloads page in the MySQL Developer Zone, which provides RPM packages that work for different platforms.

The discussion in this section applies only to the RPM packages downloaded from the MySQL Developer Zone. Installations created with these packages result in files under the system directories shown in the following table.

Table 2.6 MySQL Installation Layout for Linux RPM Packages from the MySQL Developer Zone

Directory	Contents of Directory
/usr/bin	Client programs and scripts
/usr/sbin	The mysqld server
/var/lib/mysql	Log files, databases
/usr/share/info	MySQL manual in Info format
/usr/share/man	Unix manual pages
/usr/include/mysql	Include (header) files
/usr/lib/mysql	Libraries
/usr/share/mysql	Miscellaneous support files, including error messages, character set files, sample configuration files, SQL for database installation
/usr/share/sql-bench	Benchmarks

Note

RPM distributions of MySQL are also provided by other vendors. Be aware that they may differ from those built by Oracle in features, capabilities, and conventions (including communication setup), and that the instructions in this manual do not necessarily apply to installing them. The vendor's instructions should be consulted instead. Because of these differences, RPM packages built by Oracle check whether such RPMs built by other vendors are installed. If so, the RPM does not install and produces a message explaining this.

Conflicts can arise when an RPM from another vendor is already installed, such as when a vendor's conventions about which files belong with the server and which belong with the client library differ from the breakdown used for Oracle packages. In such cases, attempts to install an Oracle RPM with rpm -i may result in messages that files in the RPM to be installed conflict with files from an installed package (denoted mysql-libs in the following paragraphs).

Each MySQL release provides a MySQL-shared-compat package that is meant to replace mysql-libs and provides a replacement-compatible client library for older MySQL series. MySQL-shared-compat is set up to make mysql-libs obsolete, but rpm explicitly refuses to replace obsoleted packages when invoked with -i (unlike -U), which is why installation with rpm -i produces a conflict.

MySQL-shared-compat can safely be installed alongside mysql-libs because libraries are installed to different locations. Therefore, it is possible to install MySQL-shared-compat first, then manually remove mysql-libs before continuing with the installation. After mysql-libs is removed, the dynamic linker stops looking for the client library in the location where mysql-libsputs it, and the library provided by the MySQL-shared-compat package takes over.

Another alternative is to install packages using yum. In a directory containing all RPM packages for a MySQL release, yum install MySQL*rpm installs them in the correct order and removes mysql-libs in one step without conflicts.

In most cases, you need install only the MySQL-server and MySQL-client packages to get a functional standard MySQL installation. The other packages are not required for a standard installation.

As of MySQL 5.6.8, new RPM install operations (not upgrades) invoke mysql_install_db with the --random-passwords option that provides for more secure MySQL installation. Invoking mysql_install_db with --random-passwords causes it to assign a random password to the MySQL root accounts, set the “password expired” flag for those accounts, and not create anonymous-user MySQL accounts. It will be necessary after installation to start the server, connect as root using the initial random password, and assign a new root password. Until this is done, root cannot do anything else. This must be done for each root account you intend to use. To change the password, you can use the SET PASSWORD statement (for example, with the mysql client). You can also use mysqladmin or mysql_secure_installation. For additional details, see Section 4.4.3, “mysql_install_db — Initialize MySQL Data Directory”. (Install operations using RPMs for Unbreakable Linux Network are unaffected because they do not use mysql_install_db.)

Important

RPMs for MySQL Cluster. Standard MySQL server RPMs built by MySQL do not provide support for the NDBCLUSTER storage engine. For more information about installing MySQL Cluster from RPMs, see Section 18.2, “MySQL Cluster Installation”.

When upgrading a MySQL Cluster RPM installation, you must upgrade all installed RPMs, including the Server and Client RPMs.

For upgrades, if your installation was originally produced by installing multiple RPM packages, it is best to upgrade all the installed packages, not just some. For example, if you previously installed the server and client RPMs, do not upgrade just the server RPM.

If the data directory exists at RPM installation time, the installation process does not modify existing data. This has the effect, for example, that accounts in the grant tables are not initialized to the default set of accounts.

If you get a dependency failure when trying to install MySQL packages (for example, error: removing these packages would break dependencies: libmysqlclient.so.10 is needed by ...), you should also install the MySQL-shared-compat package, which includes the shared libraries for older releases for backward compatibility.

The following list shows the available RPM packages. The names shown here use a suffix of .linux_glibc2.5.i386.rpm, but particular packages can have different suffixes, described later. If you plan to install multiple RPM packages, you may wish to download the RPM Bundle tar file instead, which contains multiple RPM packages so that you need not download them separately.

• MySQL-server-VERSION.linux_glibc2.5.i386.rpm

  The MySQL server. You need this unless you only want to connect to a MySQL server running on another machine.

• MySQL-client-VERSION.linux_glibc2.5.i386.rpm

  The standard MySQL client programs. You probably always want to install this package.

• MySQL-devel-VERSION.linux_glibc2.5.i386.rpm

  The libraries and include files needed to compile other MySQL clients, such as the Perl MySQL module. Install this RPM if you intend to compile C API applications.

• MySQL-shared-VERSION.linux_glibc2.5.i386.rpm

  This package contains the shared libraries (libmysqlclient.so*) that certain languages and applications need to dynamically load and use MySQL. It contains single-threaded and thread-safe libraries. Install this RPM if you intend to compile or run C API applications that depend on the shared client library.

• MySQL-shared-compat-VERSION.linux_glibc2.5.i386.rpm

  This package includes the shared libraries for older releases, but not the libraries for the current release. It contains single-threaded and thread-safe libraries. Install this package if you have applications installed that are dynamically linked against older versions of MySQL but you want to upgrade to the current version without breaking the library dependencies.

  As of MySQL 5.6.5, the MySQL-shared-compat RPM package enables users of Red Hat-provided mysql-*-5.1 RPM packages to migrate to Oracle-provided MySQL-*-5.5 packages. MySQL-shared-compat replaces the Red Hat mysql-libs package by replacing libmysqlclient.so files of the latter package, thus satisfying dependencies of other packages on mysql-libs. This change affects only users of Red Hat (or Red Hat-compatible) RPM packages. Nothing is different for users of Oracle RPM packages.

• MySQL-embedded-VERSION.linux_glibc2.5.i386.rpm

  The embedded MySQL server library.

• MySQL-test-VERSION.linux_glibc2.5.i386.rpm

  This package includes the MySQL test suite.

• MySQL-VERSION.src.rpm

  This contains the source code for all of the previous packages. It can also be used to rebuild the RPMs on other architectures (for example, SPARC).

In RPM package names, the suffix (following the VERSION value) has the following syntax:

.PLATFORM.CPU.rpm

The PLATFORM and CPU values indicate the type of system for which the package is built. PLATFORM indicates the platform and CPU indicates the processor type or family.

All packages are dynamically linked against glibc 2.5. The PLATFORM value indicates whether the package is platform independent or intended for a specific platform, as shown in the following table.

Table 2.7 MySQL Linux RPM Package Platforms

PLATFORM Value	Intended Use
linux_glibc25	Platform independent, should run on any Linux distribution that supports glibc 2.5
rhel5	Red Hat Enterprise Linux 5
el6, el7	Enterprise Linux 6 or 7
sles11, sles12	SUSE Linux Enterprise Server 11 or 12

In MySQL 5.6, only linux_glibc2.5 packages are available currently.

The CPU value indicates the processor type or family for which the package is built, as shown in the following table.

Table 2.8 MySQL Linux RPM Package CPU Identifiers

CPU Value	Intended Processor Type or Family
i386, i686	Pentium processor or better, 32 bit
x86_64	64-bit x86 processor

To see all files in an RPM package (for example, a MySQL-server RPM), run a command like this (modify the platform and CPU identifiers appropriately for your system):

shell> rpm -qpl MySQL-server-VERSION.linux_glibc2.5.i386.rpm

To perform a standard minimal installation, install the server and client RPMs:

shell> rpm -i MySQL-server-VERSION.linux_glibc2.5.i386.rpm
shell> rpm -i MySQL-client-VERSION.linux_glibc2.5.i386.rpm

To install only the client programs, install just the client RPM:

shell> rpm -i MySQL-client-VERSION.linux_glibc2.5.i386.rpm

RPM provides a feature to verify the integrity and authenticity of packages before installing them. To learn more about this feature, see Section 2.1.3, “Verifying Package Integrity Using MD5 Checksums or GnuPG”.

The server RPM places data under the /var/lib/mysql directory. The RPM also creates a login account for a user named mysql (if one does not exist) to use for running the MySQL server, and creates the appropriate entries in /etc/init.d/ to start the server automatically at boot time. (This means that if you have performed a previous installation and have made changes to its startup script, you may want to make a copy of the script so that you can reinstall it after you install a newer RPM.) See Section 2.10.5, “Starting and Stopping MySQL Automatically”, for more information on how MySQL can be started automatically on system startup.

In MySQL 5.6, for a new installation using RPM packages, the server boot scripts are installed, but the MySQL server is not started at the end of the installation, since the status of the server during an unattended installation is not known.

In MySQL 5.6, for an upgrade installation using RPM packages, if the MySQL server is running when the upgrade occurs, the MySQL server is stopped, the upgrade occurs, and the MySQL server is restarted. If the MySQL server is not already running when the RPM upgrade occurs, the MySQL server is not started at the end of the installation.

Note

Upgrading from a community version to a commercial version of MySQL requires that you first uninstall the community version and then install the commercial version. In this case, you must restart the server manually after the upgrade.

Note

The accounts created in the MySQL grant tables for an RPM installation initially have no passwords. After starting the server, you should assign passwords to them using the instructions in Section 2.10, “Postinstallation Setup and Testing”.

An RPM installation creates a user named mysql and a group named mysql on the system using the useradd, groupadd, and usermod commands. Those commands require appropriate administrative privileges, which is required for locally managed users and groups (as listed in the /etc/passwd and/etc/group files) by the RPM installation process being run by root.

If you log in as the mysql user, you may find that MySQL displays “Invalid (old?) table or database name” errors that mention .mysqlgui, lost+found,.mysqlgui, .bash_history, .fonts.cache-1, .lesshst, .mysql_history, .profile, .viminfo, and similar files created by MySQL or operating system utilities. You can safely ignore these error messages or remove the files or directories that cause them if you do not need them.

For nonlocal user management (LDAP, NIS, and so forth), the administrative tools may require additional authentication (such as a password), and will fail if the installing user does not provide this authentication. Even if they fail, the RPM installation will not abort but succeed, and this is intentional. If they failed, some of the intended transfer of ownership may be missing, and it is recommended that the system administrator then manually ensures some appropriate user and group exists and manually transfers ownership following the actions in the RPM spec file.

In MySQL 5.6.11, the RPM spec file has been updated, which has the following consequences: