卸载老版本的MySQL。查找并删除mysql有关的文件

# find / -name mysql

# rm -rf /usr/lib64/mysql /usr/share/mysql

  1. [root@localhost ~]# find / -name mysql
  2. /usr/lib64/mysql
  3. /usr/share/mysql
  4. [root@localhost ~]# rm -rf /usr/lib64/mysql /usr/share/mysql
  5. [root@localhost ~]#

上传mysql安装包并解压

# tar -zxf mysql-5.6.43-linux-glibc2.12-x86_64.tar.gz

  1. [root@localhost ~]# ls
  2. anaconda-ks.cfg mysql-5.6.-linux-glibc2.-x86_64.tar.gz
  3. [root@localhost ~]# tar -zxf mysql-5.6.-linux-glibc2.-x86_64.tar.gz
  4. [root@localhost ~]# ls
  5. anaconda-ks.cfg mysql-5.6.-linux-glibc2.-x86_64.tar.gz
  6. mysql-5.6.-linux-glibc2.-x86_64

选择安装位置并重命名

mv mysql-5.6.43-linux-glibc2.12-x86_64 /usr/mysql-5.6.43

  1. [root@localhost ~]# mv mysql-5.6.-linux-glibc2.-x86_64 /usr/mysql-5.6.
  2. [root@localhost ~]#
  3. [root@localhost ~]# ls
  4. anaconda-ks.cfg mysql-5.6.-linux-glibc2.-x86_64.tar.gz
  5. [root@localhost ~]#
  6. [root@localhost ~]# ls /usr/
  7. bin etc games include lib lib64 libexec local mysql-5.6. sbin share src tmp

添加用户组和用户

# groupadd mysql

# useradd mysql -g mysql

# groups mysql

  1. [root@localhost ~]# groupadd mysql
  2. [root@localhost ~]# useradd mysql -g mysql
  3. [root@localhost ~]# groups mysql
  4. mysql : mysql

更改MySQL目录权限,进入mysql目录

  1. [root@localhost ~]# cd /usr/mysql-5.6./
  2. [root@localhost mysql-5.6.]#
  3. [root@localhost mysql-5.6.]# ls
  4. bin COPYING data docs include lib man mysql-test README scripts share sql-bench support-files
  5. [root@localhost mysql-5.6.]#
  6. [root@localhost mysql-5.6.]# pwd
  7. /usr/mysql-5.6.
  8. [root@localhost mysql-5.6.]# chown -R mysql:mysql /usr/mysql-5.6.
  9. [root@localhost mysql-5.6.]# ll
  10. total
  11. drwxr-xr-x. mysql mysql May : bin
  12. -rw-r--r--. mysql mysql Dec : COPYING
  13. drwxr-xr-x. mysql mysql May : data
  14. drwxr-xr-x. mysql mysql May : docs
  15. drwxr-xr-x. mysql mysql May : include
  16. drwxr-xr-x. mysql mysql May : lib
  17. drwxr-xr-x. mysql mysql May : man
  18. drwxr-xr-x. mysql mysql May : mysql-test
  19. -rw-r--r--. mysql mysql Dec : README
  20. drwxr-xr-x. mysql mysql May : scripts
  21. drwxr-xr-x. mysql mysql May : share
  22. drwxr-xr-x. mysql mysql May : sql-bench
  23. drwxr-xr-x. mysql mysql May : support-files

安装相关的包

# yum install perl perl-devel autoconf -y

  1. Installed:
  2. perl-devel.x86_64 :5.16.-.el7_6
  3.  
  4. Dependency Installed:
  5. gdbm-devel.x86_64 :1.10-.el7 libdb-devel.x86_64 :5.3.-.el7 perl-ExtUtils-Install.noarch :1.58-.el7_6 perl-ExtUtils-MakeMaker.noarch :6.68-.el7
  6. perl-ExtUtils-Manifest.noarch :1.61-.el7 perl-ExtUtils-ParseXS.noarch :3.18-.el7 pyparsing.noarch :1.5.-.el7 systemtap-sdt-devel.x86_64 :3.3-.el7
  7.  
  8. Updated:
  9. perl.x86_64 :5.16.-.el7_6
  10.  
  11. Dependency Updated:
  12. libdb.x86_64 :5.3.-.el7 libdb-utils.x86_64 :5.3.-.el7 perl-libs.x86_64 :5.16.-.el7_6
  13.  
  14. Complete!

数据库初始化

# ./mysql_install_db --basedir=/usr/mysql-5.6.43/ --datadir=/usr/mysql-5.6.43/data/ --user=mysql

  1. [root@localhost ~]# cd /usr/mysql-5.6./
  2. [root@localhost mysql-5.6.]#
  3. [root@localhost mysql-5.6.]#
  4. [root@localhost mysql-5.6.]# ls
  5. bin COPYING data docs include lib man mysql-test README scripts share sql-bench support-files
  6. [root@localhost mysql-5.6.]#
  7. [root@localhost mysql-5.6.]#
  8. [root@localhost mysql-5.6.]# cd scripts/
  9. [root@localhost scripts]#
  10. [root@localhost scripts]#
  11. [root@localhost scripts]# ls
  12. mysql_install_db
  13. [root@localhost scripts]#
  14. [root@localhost scripts]#
  15. [root@localhost scripts]# ll
  16. total
  17. -rwxr-xr-x. mysql mysql Dec : mysql_install_db
  18. [root@localhost scripts]#
  19. [root@localhost scripts]#
  20. [root@localhost scripts]# ./mysql_install_db --basedir=/usr/mysql-5.6./ --datadir=/usr/mysql-5.6./data/ --user=mysql
  21. Installing MySQL system tables...-- :: [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
  22. -- :: [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
  23. -- :: [Note] /usr/mysql-5.6.//bin/mysqld (mysqld 5.6.43) starting as process 7286 ...
  24. -- :: [Note] InnoDB: Using atomics to ref count buffer pool pages
  25. -- :: [Note] InnoDB: The InnoDB memory heap is disabled
  26. -- :: [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
  27. -- :: [Note] InnoDB: Memory barrier is not used
  28. -- :: [Note] InnoDB: Compressed tables use zlib 1.2.
  29. -- :: [Note] InnoDB: Using Linux native AIO
  30. -- :: [Note] InnoDB: Using CPU crc32 instructions
  31. -- :: [Note] InnoDB: Initializing buffer pool, size = 128.0M
  32. -- :: [Note] InnoDB: Completed initialization of buffer pool
  33. -- :: [Note] InnoDB: The first specified data file ./ibdata1 did not exist: a new database to be created!
  34. -- :: [Note] InnoDB: Setting file ./ibdata1 size to MB
  35. -- :: [Note] InnoDB: Database physically writes the file full: wait...
  36. -- :: [Note] InnoDB: Setting log file ./ib_logfile101 size to MB
  37. -- :: [Note] InnoDB: Setting log file ./ib_logfile1 size to MB
  38. -- :: [Note] InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0
  39. -- :: [Warning] InnoDB: New log files created, LSN=
  40. -- :: [Note] InnoDB: Doublewrite buffer not found: creating new
  41. -- :: [Note] InnoDB: Doublewrite buffer created
  42. -- :: [Note] InnoDB: rollback segment(s) are active.
  43. -- :: [Warning] InnoDB: Creating foreign key constraint system tables.
  44. -- :: [Note] InnoDB: Foreign key constraint system tables created
  45. -- :: [Note] InnoDB: Creating tablespace and datafile system tables.
  46. -- :: [Note] InnoDB: Tablespace and datafile system tables created.
  47. -- :: [Note] InnoDB: Waiting for purge to start
  48. -- :: [Note] InnoDB: 5.6. started; log sequence number
  49. -- :: [Note] Binlog end
  50. -- :: [Note] InnoDB: FTS optimize thread exiting.
  51. -- :: [Note] InnoDB: Starting shutdown...
  52. -- :: [Note] InnoDB: Shutdown completed; log sequence number
  53. OK
  54.  
  55. Filling help tables...-- :: [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
  56. -- :: [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
  57. -- :: [Note] /usr/mysql-5.6.//bin/mysqld (mysqld 5.6.43) starting as process 7327 ...
  58. -- :: [Note] InnoDB: Using atomics to ref count buffer pool pages
  59. -- :: [Note] InnoDB: The InnoDB memory heap is disabled
  60. -- :: [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
  61. -- :: [Note] InnoDB: Memory barrier is not used
  62. -- :: [Note] InnoDB: Compressed tables use zlib 1.2.
  63. -- :: [Note] InnoDB: Using Linux native AIO
  64. -- :: [Note] InnoDB: Using CPU crc32 instructions
  65. -- :: [Note] InnoDB: Initializing buffer pool, size = 128.0M
  66. -- :: [Note] InnoDB: Completed initialization of buffer pool
  67. -- :: [Note] InnoDB: Highest supported file format is Barracuda.
  68. -- :: [Note] InnoDB: rollback segment(s) are active.
  69. -- :: [Note] InnoDB: Waiting for purge to start
  70. -- :: [Note] InnoDB: 5.6. started; log sequence number
  71. -- :: [Note] Binlog end
  72. -- :: [Note] InnoDB: FTS optimize thread exiting.
  73. -- :: [Note] InnoDB: Starting shutdown...
  74. -- :: [Note] InnoDB: Shutdown completed; log sequence number
  75. OK
  76.  
  77. To start mysqld at boot time you have to copy
  78. support-files/mysql.server to the right place for your system
  79.  
  80. PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
  81. To do so, start the server, then issue the following commands:
  82.  
  83. /usr/mysql-5.6.//bin/mysqladmin -u root password 'new-password'
  84. /usr/mysql-5.6.//bin/mysqladmin -u root -h localhost.localdomain password 'new-password'
  85.  
  86. Alternatively you can run:
  87.  
  88. /usr/mysql-5.6.//bin/mysql_secure_installation
  89.  
  90. which will also give you the option of removing the test
  91. databases and anonymous user created by default. This is
  92. strongly recommended for production servers.
  93.  
  94. See the manual for more instructions.
  95.  
  96. You can start the MySQL daemon with:
  97.  
  98. cd . ; /usr/mysql-5.6.//bin/mysqld_safe &
  99.  
  100. You can test the MySQL daemon with mysql-test-run.pl
  101.  
  102. cd mysql-test ; perl mysql-test-run.pl
  103.  
  104. Please report any problems at http://bugs.mysql.com/
  105.  
  106. The latest information about MySQL is available on the web at
  107.  
  108. http://www.mysql.com
  109.  
  110. Support MySQL by buying support/licenses at http://shop.mysql.com
  111.  
  112. New default config file was created as /usr/mysql-5.6.//my.cnf and
  113. will be used by default by the server when you start it.
  114. You may edit this file to change server settings
  115.  
  116. WARNING: Default config file /etc/my.cnf exists on the system
  117. This file will be read by default by the MySQL server
  118. If you do not want to use this, either remove it, or use the
  119. --defaults-file argument to mysqld_safe when starting the server

拷贝 my-default.cnf到/etc/my.cnf

# cd ../support-files/

# cp my-default.cnf /etc/my.cnf

  1. [root@localhost scripts]# cd ../support-files/
  2. [root@localhost support-files]#
  3. [root@localhost support-files]# ls
  4. binary-configure magic my-default.cnf mysqld_multi.server mysql-log-rotate mysql.server
  5. [root@localhost support-files]#
  6. [root@localhost support-files]# cp my-default.cnf /etc/my.cnf
  7. cp: overwrite ‘/etc/my.cnf’? yes
  8. [root@localhost support-files]#

向/etc/init.d中添加mysql的启动服务

init.d目录包含许多系统各种服务的启动和停止脚本。

  1. [root@localhost support-files]# pwd
  2. /usr/mysql-5.6./support-files
  3. [root@localhost support-files]# ls
  4. binary-configure magic my-default.cnf mysqld_multi.server mysql-log-rotate mysql.server
  5. [root@localhost support-files]# cp mysql.server /etc/init.d/mysqld
  6. [root@localhost support-files]#

修改/etc/init.d/mysqld权限

# cd /etc/init.d/

# chmod 755 mysqld

  1. [root@localhost support-files]# cd /etc/init.d/
  2. [root@localhost init.d]#
  3. [root@localhost init.d]# ls
  4. functions mysqld netconsole network README
  5. [root@localhost init.d]#
  6. [root@localhost init.d]# chmod -R mysqld
  7. [root@localhost init.d]#
  8. [root@localhost init.d]# ll
  9. total
  10. -rw-r--r--. root root Sep functions
  11. -rwxr-xr-x. root root May : mysqld
  12. -rwxr-xr-x. root root Sep netconsole
  13. -rwxr-xr-x. root root Sep network
  14. -rw-r--r--. root root Nov README

修改/etc/init.d/mysqld

# vi /etc/init.d/mysqld

配置环境变量

将MySQL配置到环境变量中,这样就可以在任何地方用mysql命令了

# vi /etc/profile

在最后添加

  1. #mysql
  2. export MYSQL_HOME=/usr/mysql-5.6.
  3. #PATH
  4. export PATH=$MYSQL_HOME/bin:$PATH

执行如下指令,使上述配置立即生效

# source /etc/profile

启动MySQL

# /etc/init.d/mysqld start

  1. [root@localhost ~]# /etc/init.d/mysqld start
  2. Starting MySQL.Logging to '/usr/mysql-5.6.43/data/localhost.localdomain.err'.
  3. ................... SUCCESS!

查看err的信息

# cd /usr/mysql-5.6.43/data/

# cat localhost.localdomain.err

  1. [root@localhost data]# cd /usr/mysql-5.6./data/
  2. [root@localhost data]#
  3. [root@localhost data]#
  4. [root@localhost data]# ls
  5. auto.cnf ibdata1 ib_logfile0 ib_logfile1 localhost.localdomain.err localhost.localdomain.pid mysql performance_schema test
  6. [root@localhost data]#
  7. [root@localhost data]# cat localhost.localdomain.err
  8. 2019-05-24 20:37:02 7566 [Note] Plugin 'FEDERATED' is disabled.
  9. -- :: [Note] InnoDB: Using atomics to ref count buffer pool pages
  10. -- :: [Note] InnoDB: The InnoDB memory heap is disabled
  11. -- :: [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
  12. -- :: [Note] InnoDB: Memory barrier is not used
  13. -- :: [Note] InnoDB: Compressed tables use zlib 1.2.
  14. -- :: [Note] InnoDB: Using Linux native AIO
  15. -- :: [Note] InnoDB: Using CPU crc32 instructions
  16. -- :: [Note] InnoDB: Initializing buffer pool, size = 128.0M
  17. -- :: [Note] InnoDB: Completed initialization of buffer pool
  18. -- :: [Note] InnoDB: Highest supported file format is Barracuda.
  19. -- :: [Note] InnoDB: rollback segment(s) are active.
  20. -- :: [Note] InnoDB: Waiting for purge to start
  21. -- :: [Note] InnoDB: 5.6. started; log sequence number
  22. -- :: [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: a27e1f65-7e20-11e9--000c294cff47.
  23. -- :: [Note] Server hostname (bind-address): '*'; port:
  24. -- :: [Note] IPv6 is available.
  25. -- :: [Note] - '::' resolves to '::';
  26. -- :: [Note] Server socket created on IP: '::'.
  27. -- :: [Note] Event Scheduler: Loaded events
  28. -- :: [Note] /usr/mysql-5.6./bin/mysqld: ready for connections.
  29. Version: '5.6.43' socket: '/tmp/mysql.sock' port: MySQL Community Server (GPL)

修改/etc/my.cnf

# vi /etc/my.cnf

添加federated

  1. # For advice on how to change settings please see
  2. # http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html
  3. # *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
  4. # *** default location during install, and will be replaced if you
  5. # *** upgrade to a newer version of MySQL.
  6.  
  7. [mysqld]
  8. federated
  9. # Remove leading # and set to the amount of RAM for the most important data
  10. # cache in MySQL. Start at % of total RAM for dedicated server, else %.
  11. # innodb_buffer_pool_size = 128M
  12.  
  13. # Remove leading # to turn on a very important data integrity option: logging
  14. # changes to the binary log between backups.
  15. # log_bin
  16.  
  17. # These are commonly set, remove the # and set as required.
  18. # basedir = .....
  19. # datadir = .....
  20. # port = .....
  21. # server_id = .....
  22. # socket = .....
  23.  
  24. # Remove leading # to set options mainly useful for reporting servers.
  25. # The server defaults are faster for transactions and fast SELECTs.
  26. # Adjust sizes as needed, experiment to find the optimal values.
  27. # join_buffer_size = 128M
  28. # sort_buffer_size = 2M
  29. # read_rnd_buffer_size = 2M
  30.  
  31. sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

再次重新启动

  1. [root@localhost ~]# /etc/init.d/mysqld stop
  2. Shutting down MySQL.. SUCCESS!
  3. [root@localhost ~]#
  4. [root@localhost ~]#
  5. [root@localhost ~]# /etc/init.d/mysqld start
  6. Starting MySQL... SUCCESS!
  7. [root@localhost ~]#
  8. [root@localhost ~]# ps -aux | grep mysqld
  9. root 0.0 0.0 pts/ S : : /bin/sh /usr/mysql-5.6./bin/mysqld_safe --datadir=/usr/mysql-5.6./data --pid-file=/usr/mysql-5.6./data/localhost.localdomain.pid
  10. mysql 9.6 24.2 pts/ Sl : : /usr/mysql-5.6./bin/mysqld --basedir=/usr/mysql-5.6. --datadir=/usr/mysql-5.6./data --plugin-dir=/usr/mysql-5.6./lib/plugin --user=mysql --log-error=localhost.localdomain.err --pid-file=/usr/mysql-5.6./data/localhost.localdomain.pid
  11. root 0.0 0.0 pts/ S+ : : grep --color=auto mysqld

登陆MySQL数据库

# mysql -uroot -p

  1. [root@localhost ~]# mysql -uroot -p
  2. Enter password:
  3. Welcome to the MySQL monitor. Commands end with ; or \g.
  4. Your MySQL connection id is
  5. Server version: 5.6. MySQL Community Server (GPL)
  6.  
  7. Copyright (c) , , Oracle and/or its affiliates. All rights reserved.
  8.  
  9. Oracle is a registered trademark of Oracle Corporation and/or its
  10. affiliates. Other names may be trademarks of their respective
  11. owners.
  12.  
  13. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
  14.  
  15. mysql> select user,host,password from mysql.user;
  16. +------+-----------------------+----------+
  17. | user | host | password |
  18. +------+-----------------------+----------+
  19. | root | localhost | |
  20. | root | localhost.localdomain | |
  21. | root | 127.0.0.1 | |
  22. | root | :: | |
  23. | | localhost | |
  24. | | localhost.localdomain | |
  25. +------+-----------------------+----------+
  26. rows in set (0.00 sec)

授权并设置root密码

mysql> update mysql.user set password=password('000000') where user='root' and host='localhost';

mysql> grant all privileges on *.* to root@'%' identified by '000000';

  1. mysql> update mysql.user set password=password('') where user='root' and host='localhost';
  2. Query OK, row affected (0.04 sec)
  3. Rows matched: Changed: Warnings:
  4.  
  5. mysql> flush privileges;
  6. Query OK, rows affected (0.00 sec)
  7.  
  8. mysql> select user,host,password from mysql.user;
  9. +------+-----------------------+-------------------------------------------+
  10. | user | host | password |
  11. +------+-----------------------+-------------------------------------------+
  12. | root | localhost | *032197AE5731D4664921A6CCAC7CFCE6A0698693 |
  13. | root | localhost.localdomain | |
  14. | root | 127.0.0.1 | |
  15. | root | :: | |
  16. | | localhost | |
  17. | | localhost.localdomain | |
  18. +------+-----------------------+-------------------------------------------+
  19. rows in set (0.00 sec)
  20.  
  21. mysql> grant all privileges on *.* to root@'%' identified by '';
  22. Query OK, rows affected (0.00 sec)
  23.  
  24. mysql> flush privileges;
  25. Query OK, rows affected (0.00 sec)
  26.  
  27. mysql> select user,host,password from mysql.user;
  28. +------+-----------------------+-------------------------------------------+
  29. | user | host | password |
  30. +------+-----------------------+-------------------------------------------+
  31. | root | localhost | *032197AE5731D4664921A6CCAC7CFCE6A0698693 |
  32. | root | localhost.localdomain | |
  33. | root | 127.0.0.1 | |
  34. | root | :: | |
  35. | | localhost | |
  36. | | localhost.localdomain | |
  37. | root | % | *032197AE5731D4664921A6CCAC7CFCE6A0698693 |
  38. +------+-----------------------+-------------------------------------------+
  39. rows in set (0.00 sec)

关闭防火墙客户端连接

参考博客

https://www.cnblogs.com/dengshihuang/p/8029092.html

https://blog.csdn.net/qiushisoftware/article/details/86617699

Linux--Linux服务器数据库MySQL5.6.43版本安装过程说明(阿里云服务器)

https://blog.csdn.net/fumushan/article/details/87073240

阿里云CentOS安装mysql-5.6.43

https://blog.csdn.net/qiushisoftware/article/details/86617699

centos7安装mysql-5.6.43二进制包的更多相关文章

  1. Centos7 安装MySQL 5.7 (通用二进制包)

    1.下载安装包 下载地址 https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.17-linux-glibc2.5-x86_64.tar.gz ...

  2. CentOS7安装MySQL的方法之RPM包方式

        CentOS7安装MySQL的方法之RPM包方式        

  3. CentOS7安装MySQL的方法之通用二进制格式

      CentOS7安装MySQL的方法之通用二进制格式          

  4. [CentOs7]安装mysql(2)

    摘要 之前安装过一次mysql,最后配置,发现在本地无法连接,重启服务的时候一直卡在那里不动,感觉是安装的过程出问题,最后没办法还是卸载了,然后重新安装一下. [CentOs7]安装mysql Mys ...

  5. centos7安装mysql(yum)

    centos7安装mysql(yum) ----安装环境----依赖安装----检查mysql是否已安装----安装----验证是否添加成功----选择要启用的mysql版本----通过Yum安装my ...

  6. centos7安装Mysql爬坑记录

    centos7安装Mysql爬坑记录   查看是否已安装 使用下列命令查看是否已经安装过mysql/mariadb/PostgreSQL 如果未安装,不返回任何结果(ECS的centos镜像默认未安装 ...

  7. Centos7 安装mysql服务器并开启远程访问功能

    大二的暑假,波波老师送了一个华为云的服务器给我作测试用,这是我程序员生涯里第一次以root身份拥有一台真实的云服务器 而之前学习的linux知识在这时也派上了用场,自己的物理机用的是ubuntu系统, ...

  8. CentOS7安装mysql提示“No package mysql-server available.”

    针对centos7安装mysql,提示"No package mysql-server available."错误,解决方法如下: Centos 7 comes with Mari ...

  9. centos7安装mysql

    centos7安装mysql 1 查找系统是否安装了myql rpm -q mysql mysql-server1.1如果安装了.就删除 sudo yum -y remove mysql mysql- ...

  10. Mysql 官网下载二进制包_图解步骤

    MYSQL下载方式 下载二进制包,直接使用wget下载 [root@db ~]# wget https://downloads.mysql.com/archives/get/p/23/file/mys ...

随机推荐

  1. Java入门 - 语言基础 - 18.正则表达式

    原文地址:http://www.work100.net/training/java-regular-expression.html 更多教程:光束云 - 免费课程 正则表达式 序号 文内章节 视频 1 ...

  2. Java数组合并方法学习。

    参考博客: https://blog.csdn.net/liu_005/article/details/72760392 https://blog.csdn.net/jaycee110905/arti ...

  3. 「 神器 」在线PDF文件管理工具和图片编辑神器

    每天进步一丢丢,连接梦与想 在线PDF文件管理工具 完全免费的PDF文件在线管理工具,其功能包括:合并PDF文件.拆分PDF文件.压缩PDF文件.Office文件转换为PDF文件.PDF文件转换为JP ...

  4. 个人第四次作业——Alpha项目测试

    一.格式描述 这个作业属于哪个课程 https://edu.cnblogs.com/campus/xnsy/GeographicInformationScience/ 这个作业要求在哪里 https: ...

  5. 看看AQS阻塞队列和条件队列

    上一篇简单介绍了AQS,我们大概知道AQS就是一个框架,把很多功能都给实现了(比如入队规则,唤醒节点中的线程等),我们如果要使用的话只需要实现其中的一些方法(比如tryAcquire等)就行了!这次主 ...

  6. UML--->用例图梳理

    用例图梳理 概述 用例图主要用来描述"用户.需求.系统功能单元"之间的关系.它展示了一个外部用户能够观察到的系统功能模型图. 用例图的主要目的是帮助开发团队以一种可视化的方式理解系 ...

  7. MySQL5.7 中的query_cache_size

    摘自:http://jackyrong.iteye.com/blog/2173523 1 原理    MySQL查询缓存保存查询返回的完整结果.当查询命中该缓存,会立刻返回结果,跳过了解析,优化和执行 ...

  8. Java8新特性一点通 | 回顾字符转日期&JoinArray使用

    StringToDate日期转换 Join Array使用 StringToDate日期转换 Convert string to date in ISO8601 format 利用LocalDate. ...

  9. 三、Django学习之单表查询接口

    查询接口 all() 查询所有结果,结果是queryset类型 filter(**kwargs) and条件关系:参数用逗号分割表示and关系 models.Student.objects.filte ...

  10. 九 Shell中的数组

    数组:用一个变量存储一组数据,并能够对这组数据中的某一个数据单独操作. 数组的类型:一维数组.二维数组.多维数组 变量的类型 Shell中默认无类型 变量的值默认均视为文本 用在数字运算中时,自动将其 ...