参考文章
1.Ubuntu 18.04安装mysql
2.Python3 MySQL 数据库连接 - PyMySQL 驱动

运行环境:Ubuntu 18.04

以下所有命令均在root用户下执行。

一、安装mysql和PyMySQL

(1)安装mysql。

apt install mysql-server -y
apt install mysql-client -y
apt install libmysqlclient-dev -y

(2)修改默认密码。
cat /etc/mysql/debian.cnf,显示如下:
在这里插入图片描述
图有‘user=debian-sys-maint’,即为自动配置的默认用户,
‘password=zNBBBmhoGQuTxEzE’,即为自动配置的密码。

mysql -u debian-sys-maint -p # 之后再输入自动配置的密码
use mysql;
# 密码改成123
update mysql.user set authentication_string=password('123') where user='root' and Host ='localhost';
update user set plugin="mysql_native_password"; 
flush privileges;
quit;

(3)创建数据库BIGDATA。

service mysql restart # 重启mysql
mysql -u root -p # 然后输入密码123进入mysql
create database BIGDATA; # 创建数据库BIGDATA
show databases; # 查看所有数据库
quit # 退出mysql

(4)安装python3-pip和PyMySQL。

apt install python3-pip -y
pip3 install PyMySQL

二、编写python代码,操作MySQL

(1)连接数据库并打印SQL版本号。
vim version.py,内容如下:

#!/usr/bin/python3
# -*- coding: UTF-8 -*-
# 功能:打印SQL版本号

import pymysql as pysql

# 打开数据库连接
db = pysql.connect("localhost", "root", "123", "BIGDATA") # ip、用户、密码、数据库名称

# 使用 cursor() 方法创建一个游标对象 cursor
cursor = db.cursor()

# 使用 execute()  方法执行 SQL 查询
cursor.execute("SELECT VERSION()")

# 使用 fetchone() 方法获取单条数据
data = cursor.fetchone()

print ("Database vesion: %s " % data)

db.close()

(2)创建EMPLOYEE表。
vim create.py,内容如下:

#!/usr/bin/python3
# -*- coding: UTF-8 -*-
# 功能:创建EMPLOYEE表

import pymysql as pysql

db = pysql.connect("localhost", "root", "123", "BIGDATA")

cursor = db.cursor()

sql = """CREATE TABLE EMPLOYEE (
        NAME CHAR(20) NOT NULL,
        AGE INT,
        GENDER CHAR(1),
        INCOME FLOAT )"""

try:
    cursor.execute(sql)
    db.commit()
    print("Create table EMPLOYEE successfully!")
except Exception as e:
    print(e)
    db.rollback()

db.close()

(3)向EMPLOYEE表中批量插入n行随机数构成的数据。
vim insert.py,内容如下:

#!/usr/bin/python3
# -*- UTF-8 -*-
# 功能:插入n行随机数构成的数据

import pymysql as pysql
from random import randint
from random import choice

db = pysql.connect("localhost", "root", "123", "BIGDATA")

cursor = db.cursor()

n = 10
for i in range(n):
    # Name: 3-8, Abc
    # ascii : int -> char
    ## random, chr
    l = randint(3, 8) # get a random integer from [3,8]
    name = ""
    name += chr(randint(65, 90)) # Lowercase letters
    for j in range(l - 1):
        name += chr(randint(97, 122)) # Uppercase letters

    # Age: 18-55
    age = randint(18, 55)

    # Gender : "M", "F"
    genders = ["M", "F"]
    gender = choice(genders)

    # Income: 1000-10000
    income = randint(1000,10000)

    sql = "INSERT INTO EMPLOYEE (NAME, AGE, GENDER, INCOME) VALUES ('%s', '%s', '%s', '%s')" \
            % (name, age, gender, income)

    try:
        cursor.execute(sql)
        db.commit()
    except Exception as e:
        print(e)
        db.rollback()

print("Insert %s lines successfully!" % n)
db.close()

(4)查看EMPLOYEE表的数据。
vim show.py,内容如下:

#!/usr/bin/python3
# -*- coding: UTF-8 -*-
# 功能:查看EMPLOYEE表的数据

import pymysql as pysql

db = pysql.connect("localhost", "root", "123", "BIGDATA")

cursor = db.cursor()

sql = "SELECT * FROM EMPLOYEE"

try:
    cursor.execute(sql)
    results = cursor.fetchall() # fetchall接收返回结果的全部行
    if results: # results不为空
        for r in results:
            print("NAME:%s\tAGE:%s\tGENDER:%s\tINCOME:%s" % (r[0], r[1], r[2], r[3]))
    else:
        print("No data!")
except Exception as e:
    print(e)
    db.rollback()

db.close()

(5)删除EMPLOYEE表中的所有数据。
vim delete.py,内容如下:

#!/usr/bin/python3
# -*- UTF-8 -*-
# 功能:删除EMPLOYEE表中的所有数据

import pymysql as pysql

db = pysql.connect("localhost", "root", "123", "BIGDATA")

cursor = db.cursor()

sql = "DELETE FROM CHINA"

try:
    cursor.execute(sql)
    db.commit()
    print("Delete all data of table EMPLOYEE successfully!")
except Exception as e:
    print(e)
    db.rollback()

db.close()

(6)按顺序运行之前编写的python程序。

chmod +x *py
ll
./version.py 
./create.py 
./insert.py 
./show.py 
./delete.py 
./show.py 

运行结果如下图:
在这里插入图片描述