sqlalchemy用习惯了。。。献丑来一段Python代码吧
```Python
# -*- coding:utf-8 -*-
from sqlalchemy import and_
from sqlalchemy import Column, INT, FLOAT, VARCHAR
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()


class Test_db:
    def __init__(self):
        """此处填上自己的连接配置"""
        self.engine = create_engine(
            'mysql+pymysql://username:password@host:port/db_name?charset=utf8')
        db_session = sessionmaker(bind=self.engine)
        self.session = db_session()

    def query_all(self, target_class, query_filter):
        result_list = self.session.query(target_class).filter(query_filter).all()
        self.session.close()
        return result_list


class Heros(Base):
    """定义表结构"""
    __tablename__ = 'heros'
    id = Column(INT(), primary_key=True)
    name = Column(VARCHAR(255))
    hp_max = Column(FLOAT())
    mp_max = Column(FLOAT())

    def __init__(self, id, name, hp_max, mp_max):
        self.id = id
        self.name = name
        self.hp_max = hp_max
        self.mp_max = mp_max


if __name__ == '__main__':
    db_obj = Test_db()
    query_filter = and_(Heros.hp_max > 6000)
    heros = db_obj.query_all(Heros, query_filter)
    for hero_info in heros:
        print("id:{}, name:{}, hp_max:{}, mp_max:{}".format(hero_info.id, hero_info.name,
                                                            hero_info.hp_max, hero_info.mp_max))
```
id:10000, name:夏侯惇, hp_max:7350.0, mp_max:1746.0
id:10046, name:钟馗, hp_max:6280.0, mp_max:1988.0
id:10048, name:鬼谷子, hp_max:7107.0, mp_max:1808.0
id:10051, name:赵云, hp_max:6732.0, mp_max:1760.0
id:10052, name:橘石京, hp_max:7000.0, mp_max:0.0
id:10055, name:杨戬, hp_max:7420.0, mp_max:1694.0
id:10056, name:达摩, hp_max:7140.0, mp_max:1694.0
id:10057, name:孙悟空, hp_max:6585.0, mp_max:1760.0
id:10058, name:刘备, hp_max:6900.0, mp_max:1742.0
.....执行结果有点多字数限制了
Process finished with exit code 0

sql = 'DELETE FROM player WHERE name = %s'
val = (" 约翰 - 科林斯 ")
cursor.execute(sql)
db.commit()
print(cursor.rowcount, " 记录删除成功。")
这里写错了哇，这样写才不会报错：
sql = 'DELETE FROM player WHERE player_name = %s'
val = (" 约翰 - 科林斯 ", )
cursor.execute(sql, val)
db.commit()
print(cursor.rowcount, " 记录删除成功。")

# -*- coding: UTF-8 -*-
import mysql.connector
import traceback

# 打开数据库连接
db = mysql.connector.connect(
    host="localhost",
    user="root",
    passwd="123456", # 写上你的数据库密码
    database='nba',
    auth_plugin='mysql_native_password'
)

# 获取操作游标
cursor = db.cursor()

try:

    # 查询heros 表中最大生命值大于 6000 的英雄进行查询，并且输出相应的属性值。
    sql = 'SELECT name, hp_max FROM heros WHERE hp_max > %s ORDER BY hp_max DESC'
    val = (6000,)
    cursor.execute(sql, val)
    data = cursor.fetchall()
    for each_player in data:
        print(each_player)
except Exception as e:
  # 打印异常信息
  traceback.print_exc()
  # 回滚
  db.rollback()
finally:
  # 关闭游标 & 数据库连接
  cursor.close()
  db.close()

输出：

('廉颇', 9328.0)
('白起', 8638.0)
('程咬金', 8611.0)
('刘禅', 8581.0)
('牛魔', 8476.0)
('张飞', 8341.0)
('庄周', 8149.0)
('刘邦', 8073.0)
('项羽', 8057.0)
('亚瑟', 8050.0)
('东皇太一', 7669.0)
('典韦', 7516.0)
('曹操', 7473.0)
('杨戬', 7420.0)
('夏侯惇', 7350.0)
('吕布', 7344.0)
('哪吒', 7268.0)
('墨子', 7176.0)
('老夫子', 7155.0)
('达摩', 7140.0)
('鬼谷子', 7107.0)
('关羽', 7107.0)
('钟无艳', 7000.0)
('橘石京', 7000.0)
('刘备', 6900.0)
('太乙真人', 6835.0)
('孙膑', 6811.0)
('赵云', 6732.0)
('扁鹊', 6703.0)
('铠', 6700.0)
('露娜', 6612.0)
('孙悟空', 6585.0)
('钟馗', 6280.0)
('雅典娜', 6264.0)
('兰陵王', 6232.0)
('宫本武藏', 6210.0)
('娜可露露', 6205.0)
('高渐离', 6165.0)
('芈月', 6164.0)
('不知火舞', 6014.0)
('孙尚香', 6014.0)

Process finished with exit code 0

核心代码：
cursor = db.cursor()

sql = "select name,hp_max from heros where hp_max > %s"
val = (6000,)
cursor.execute(sql,val)
data = cursor.fetchall()
注意：val里面的元素后面必须要加英文逗号，不加或者中文逗号都会报错

import pymysql
import pymysql.cursors


cfg = {
    "host": "127.0.0.1",
    "user": "root",
    "passwd": "toor",
    "database": "test",
    "charset": "utf8mb4",
    "autocommit": True,
    'cursorclass':pymysql.cursors.DictCursor
}

db_con = pymysql.connect(**cfg)

try:
    with db_con.cursor() as cur:
        cur.execute("SELECT id,name,hp_max FROM heros WHERE hp_max > 6000 ")
        res = cur.fetchall()

    for i in res:
        print(i)
finally:
    db_con.close()

-- >=2.08 插入的数据显示不出来

__author__ = 'Administrator'

# -*- coding: UTF-8 -*-
import traceback
import json
import mysql.connector
# 打开数据库连接
db = mysql.connector.connect(
       host="localhost",
       user="root",
       passwd="hjf@2019", # 写上你的数据库密码
       database='nba',
       auth_plugin='mysql_native_password'
)
# 获取操作游标
cursor = db.cursor()
# 执行 SQL 语句
#cursor.execute("SELECT VERSION()")
# 获取一条数据
#data = cursor.fetchone()
#print("MySQL 版本: %s " % data)
# 关闭游标 & 数据库连接



# 插入新球员

#sql = "INSERT INTO player (team_id,player_id,player_name,height) VALUES (%s, %s, %s,%s)"
#val = (1003, 10038," 约翰 - 科林斯 ", 2.08)
#cursor.execute(sql,val)
#db.commit()
#print(cursor.rowcount, " 记录插入成功。")


# 查询身高大于等于 2.08 的球员
sql = 'SELECT team_id, player_id, player_name, height FROM player WHERE height >=2.08'
cursor.execute(sql)
data = cursor.fetchall()
for each_player in data:
  print(each_player)



cursor.close()
db.close()

__author__ = 'Administrator'

# -*- coding: UTF-8 -*-
import traceback
import json
import mysql.connector
# 打开数据库连接
db = mysql.connector.connect(
       host="localhost",
       user="root",
       passwd="hjf@2019", # 写上你的数据库密码
       database='nba',
       auth_plugin='mysql_native_password'
)
# 获取操作游标
cursor = db.cursor()
# 执行 SQL 语句
#cursor.execute("SELECT VERSION()")
# 获取一条数据
#data = cursor.fetchone()
#print("MySQL 版本: %s " % data)
# 关闭游标 & 数据库连接



# 插入新球员

sql = "INSERT INTO player (team_id,player_id,player_name,height) VALUES (%s, %s, %s,%s)"
val = (1003, 10038," 约翰 - 科林斯 ", 2.08)
cursor.execute(sql,val)
db.commit()
print(cursor.rowcount, " 记录插入成功。")

cursor.close()
db.close()

python连接mysql时报错【mysql.connector.errors.NotSupportedError: Authentication plugin 'caching_sha2_password' is not support】。
原因是：mysql8.0.11使用了Use Strong Password Encryption for Authentication即强密码加密。
通常的处理方法是：重装mysql【装更低版本的或者将Use Strong Password Encryption for Authentication改为Use Legacy Authentication Method(在Authentication Method中改)】
还有一种更好的方案，那就是使用【pymysql】库来连接，代码如下：
    db_host = "localhost"
    db_username = "root"
    db_password = "123456"
    db_name = "database_name"
    conn = pymysql.connect(
        host=db_host,
        user=db_username,
        passwd=db_password,
        database=db_name,
    )

# -*- coding: UTF-8 -*-

import mysql.connector
# 打开数据库连接
db = mysql.connector.connect(
       host="localhost",
       user="root",
       passwd="root", # 写上你的数据库密码
       database='test',
       auth_plugin='mysql_native_password'
)
# 获取操作游标
cursor = db.cursor()
sql = 'SELECT * FROM heros WHERE hp_max>=6000'
cursor.execute(sql)
data = cursor.fetchall()
for each_hero in data:
  print(each_hero)
cursor.close()
db.close()