这篇文章主要是关于MySQL在编译安装时，可能出现的错误的解决方法。MySQL正确的编译安装操作见前文《CentOS 7.1编译安装MySQL 5.7.7RC》。
1 没有安装MySQL所需要的boost库测试发现编译MySQL5.7以及更高的版本时，都需要下载并引用或者直接安装boost库，否则在执行cmake命令时会报如下错误：
-- Running cmake version 3.2.1 -- Configuring with MAX_INDEXES = 64U -- SIZEOF_VOIDP 8 -- MySQL 5.7.6-m16 [MySQL版本] -- Packaging as: mysql-5.7.6-m16-Linux-x86_64 -- Looked for boost/version.hpp in and -- BOOST_INCLUDE_DIR BOOST_INCLUDE_DIR-NOTFOUND -- LOCAL_BOOST_DIR -- LOCAL_BOOST_ZIP -- Could not find (the correct version of) boost. [关键错误信息] -- MySQL currently requires boost_1_57_0 [解决办法] CMake Error at cmake/boost.cmake:76 (MESSAGE): [具体错误和解决方法] You can download it with -DDOWNLOAD_BOOST=1 -DWITH_BOOST=<directory> This CMake script will look for boost in <directory>. If it is not there, it will download and unpack it (in that directory) for you. If you are inside a firewall, you may need to use an http proxy: export http_proxy=http://example.com:80 Call Stack (most recent call first): cmake/boost.cmake:228 (COULD_NOT_FIND_BOOST) CMakeLists.txt:452 (INCLUDE) -- Configuring incomplete, errors occurred! See also "/mydata/mysql-5.7.6-m16/CMakeFiles/CMakeOutput.log".解决方法：直接按照前文《2015博客升级记(四)：CentOS 7.1编译安装MySQL5.7.7rc》小节2中的方法安装Boost库即可。或者先下载Boost库，然后通过在cmake命令后面添加参数-DDOWNLOAD_BOOST=1 -DWITH_BOOST=Boost库路径即可。
2 执行cmake时缺少Ncurses库的支持Ncurses提供功能键定义(快捷键)，屏幕绘制以及基于文本终端的图形互动功能的动态库。
[root@typecodes ~]# yum -y install ncurses-devel -- Could NOT find Curses (missing: CURSES_LIBRARY CURSES_INCLUDE_PATH) CMake Error at cmake/readline.cmake:64 (MESSAGE): Curses library not found. Please install appropriate package, remove CMakeCache.txt and rerun cmake.On Debian/Ubuntu, package name is libncurses5-dev, on RedHat and derivates it is ncurses-devel. Call Stack (most recent call first): cmake/readline.cmake:107 (FIND_CURSES) cmake/readline.cmake:181 (MYSQL_USE_BUNDLED_EDITLINE) CMakeLists.txt:480 (MYSQL_CHECK_EDITLINE) -- Configuring incomplete, errors occurred! See also "/mydata/mysql-5.7.6-m16/CMakeFiles/CMakeOutput.log". See also "/mydata/mysql-5.7.6-m16/CMakeFiles/CMakeError.log".解决方法：直接执行命令yum -y install ncurses-devel安装Ncurses即可。
3 安装MySQL完后，无法正常启动服务在安装完MySQL后，执行命令service mysqld start失败，也即无法正常启动MySQL服务。
解决方法：主要通过命令systemctl status mysqld.service和MySQL的日志来分析。如上图所示，在日志文件/var/log/mysql/error.log中可以看到具体的ERROR信息：Could not create unix socket lock file /var/run/mysql/mysql.sock.lock。这种错误一般都是目录不存在或者权限不足，所以我们直接使用命令mkdir -p /var/log/mysql/创建该目录即可，然后可以设置目录权限chown -R mysql:mysql /var/log/mysql/。
4 操作MySQL时，报错You must SET PASSWORD before executing this statement用MySQL的root用户登录数据库后，如果之前没有设置密码，那么执行任何操作命令时，会提示如下错误信息。
mysql> CREATE DATABASE `testmysqldatabase` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci; ERROR 1820 (HY000): You must SET PASSWORD before executing this statement常规的使用MySQL安全模式的解决方法如下，但是在MySQL5.7以及更高版本下是行不通的。
[root@typecodes ~]# service mysqld stop Shutting down MySQL..[ OK ] [root@typecodes ~]# /mydata/mysql/bin/mysqld_safe --user=mysql --skip-networking --skip-grant-tables & [1] 3688 [root@typecodes ~]# 150409 23:02:02 mysqld_safe Logging to '/var/log/mysql/error.log'. 150409 23:02:02 mysqld_safe Starting mysqld daemon with databases from /mydata/mysql/data ######重新登录mysql后，设置root密码 mysql> set password='this is a password sample'; ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement有效的解决方法：
[root@typecodes ~]# mysql -u root -p [使用root用户登录] Enter password: [无密码，直接回车] Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 Server version: 5.7.6-m16 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> select * from mysql.user; ERROR 1820 (HY000): You must SET PASSWORD before executing this statement mysql> set password='this is a password sample'; ERROR 1819 (HY000): Your password does not satisfy the current policy requirements ######设置当前root用户密码 mysql> set password='MYSQLroota7612198981@'; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec)