1.导入模块，进入mysql

import pymysql
db = pymysql.Connect(user='root',passwd='***')
cur = db.cursor()
#cursor为控制游标

2.创建删除库

sql = 'create database guoguo'
#创建名字为guoguo的库
sql = 'drop database guoguo'
#删除库
sql = 'show databases'
#查看现有数据库（文件夹）
sql = ' use guoguo'
#进入guoguo的库

cur.excute(sql)     #即为执行该操作

3.创建table

数值型 int
小数型 decimal(m,d)
字符串 varchar(5) 非定长的字符串
时间性 timestamp 时间戳

sql = 
    """
    create table user(
    id  int  unsigned  not null  auto_increment  comment  '用户id'，
    user_name  varchar(20)  not null  comment  '用户名',
    age  tinyint  unsigned  not null  comment  '用户年龄',
    fee  decimal(10,2)  not null  default  0.00  comment  '用户余额',
    created_at  timestamp  not null  comment  '注册时间',
    primary  key(id)
    )
   """
# 名字 类型 性质（not null) 是否自增 comment ''
sql = 'show tables'
#查看所有的tables(excel)
sql = 'desc guoguo'
#查看guoguo（excel中的表头）
try:
    cur.excute(sql)
    db.commit()
except:
    db.rollback()
#发生错误时回滚
db.close
#关闭数据库

4.增删改查

#增加
sql = " insert into guoguo( \
      first_name, last_name, id, gender) \
      values (%s,%s,%s,%s) " \
      %('G','guoguo',2170,'female')
# insert into guoguo (名字） values (数据）

#删除
sql = " drop table guoguo"
sql = "delete from guoguo where id = %s"%(2170)
#删除excel用drop，删除内容用delete

#改变
sql = "alter table guoguo rename to guoguos"
sql = "alter table guoguo modify first_name varchar(50)"
sql = "update guoguo set age = %s where id in (2,3,5)"%(20)
#改变excel的名字和性质用alter rename/ modify 改变excel里面的内容

#查询
sql = "select * from guoguo where age >= 25"

try:
   cursor.execute(sql)
   # 获取所有记录列表
   results = cursor.fetchall()   #fetchone和fetchall
   for row in results:
      fname = row[0]
      lname = row[1]
      age = row[2]
      gender = row[3]
      income = row[4]
       # 打印结果
      print ("fname=%s,lname=%s,age=%s,gender=%s,income=%s" % \
             (fname, lname, age, sex, income ))
except:
   print ("Error: unable to fetch data")

db.close()