马哥博客N46第12周作业

1、通过ansible Roles编排实现 httpd 角色的部署
mkdir -pv /data/ansible/roles/httpd/{tasks,handlers,files}

cd /data/ansible/roles/httpd

vim tasks/main.yml
- include: group.yml
- include: user.yml
- include: install.yml
- include: config.yml
- include: index.yml
- include: service.yml

vim tasks/group.yml
- name: create httpd group
group: name=apache system=yes gid=88

vim tasks/user.yml
- name: create user
user: name=apache system=yes shell=/sbin/nologin home=/var/www uid=88 group=apache

vim tasks/install.yml
- name: install httpd
yum: name=httpd

vim tasks/config.yml
- name: config file
copy: src=httpd.conf dest=/etc/httpd/conf/
notify: restart httpd
vim task/index.yml
- name: index.html
copy: src=index.html dest=/var/www/html
vim tasks/service.yml
- name: start httpd
service: name=httpd state=started enabled=yes
vim handlers/main.yml
- name: restart httpd
service: name=httpd state=restarted

vim /data/ansible/role_httpd.yml
---
#httpd role
- host: websrvs
roles:
- httpd

ansible-playbook /data/ansible/role_httpd.yml

2、简述 MySQL 数据库访问的执行过程。
客户端发起一条SQL语句到SQL服务器，经过MySQL语法语义检查，通过优化器生成最佳执行计划，通过执行计划从存储引擎获取数据，返回客户端；
3、S E L E C T 语句的完整语法较复杂，但至少包括的部分是 (B )
A．仅 S E L E C T
B．S E L E C T ，F R O M
C．S E L E C T ，G R O U P
D．S E L E C T ，I N T O
4、一张表的主键个数为 (C )
A．至多 3 个 B．没有限制
C．至多 1 个 D．至多 2 个