pymysql

1、增、删、改

2、查 fetchone，fetchmany，fetchall

3、获取插入的最后一条数据的自增ID

4、封装pymsql

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1、增、删、改

#安装
pip3 install pymysql

import pymysql
#链接
conn=pymysql.connect(host='localhost',user='root',password='123',database='egon')
#游标
cursor=conn.cursor()


#part1
# sql='insert into userinfo(name,password) values(%s,%s);'
# res=cursor.execute(sql,("root","123456")) #执行sql语句，返回sql影响成功的行数
# print(res)

#part2
sql='insert into userinfo(name,password) values(%s,%s);'
res=cursor.executemany(sql,[("root","123456"),("lhf","12356"),("eee","156")]) #执行sql语句，返回sql影响成功的行数
print(res)

conn.commit() #提交后才发现表中插入记录成功
cursor.close()
conn.close()

2、查 fetchone，fetchmany，fetchall

import pymysql
#链接
conn=pymysql.connect(host='localhost',user='root',password='123',database='egon')
#游标
cursor=conn.cursor()

#执行sql语句
sql='select * from userinfo;'
rows=cursor.execute(sql) #执行sql语句，返回sql影响成功的行数rows,将结果放入一个集合，等待被查询

# cursor.scroll(3,mode='absolute') # 相对绝对位置移动
# cursor.scroll(3,mode='relative') # 相对当前位置移动
res1=cursor.fetchone()
res2=cursor.fetchone()
res3=cursor.fetchone()
res4=cursor.fetchmany(2)
res5=cursor.fetchall()
print(res1)
print(res2)
print(res3)
print(res4)
print(res5)
print('%s rows in set (0.00 sec)' %rows)

conn.commit() #提交后才发现表中插入记录成功
cursor.close()
conn.close()

3、获取插入的最后一条数据的自增ID

import pymysql
conn=pymysql.connect(host='localhost',user='root',password='123',database='egon')
cursor=conn.cursor()

sql='insert into userinfo(name,password) values("xxx","123");'
rows=cursor.execute(sql)
print(cursor.lastrowid) #在插入语句后查看

conn.commit()

cursor.close()
conn.close()

4、封装pymsql

 存储数据库信息application.yaml文件：

测试数据库:
############    数据库      ############
    host_name: '192.168.xx.xx'
    port: 3306
    service_name: testdb
    username: 'root'
    password: '123456'

python代码封装：

import pymysql
import os
import sys
import yaml

sys.setrecursionlimit(10000)  # 例如这里设置为一万

''' 公共类'''
class MyMysql(object):
    def __init__(self, db_path, db_name):
        '''
        :param db_path: 获取数据库配置文件路径
        :param db_name: 数据库名
        '''
        self.db_conf = self._get_yamlMsg(db_path).get(db_name)
        self.host = self.db_conf.get('host_name')
        self.port = self.db_conf.get('port')
        self.db = self.db_conf.get('service_name', None)
        self.username = self.db_conf.get('username')
        self.password = self.db_conf.get('password')

    def _get_yamlMsg(self, sql_path):
        '''
        # open方法打开直接读出来
        :return:
        '''
        with open(sql_path, 'r', encoding='utf-8') as f:
            sqlMsg = f.read()
        # 用load方法转字典
        sql_dic = yaml.load(sqlMsg)
        return sql_dic

    def get_connection(self):
        try:
            self.con = pymysql.Connect(host=self.host,port=self.port,user=self.username,
                                    passwd=self.password,db=self.db,charset='utf8')
        except Exception as e:
            print('连接数据库出错：', e)

    def get_cur(self):
        return self.con.cursor()


    def search(self, sql, data=None):
        '''
        查询
        :param sql:
        :return:
        '''
        try:
            cur = self.get_cur()
            cur.execute(sql)
            lines = cur.fetchall()
        except Exception as e:
            print('数据库查询出错：', e)
            cur.close()
            self.con_close()
        cur.close()
        return lines

    def excute(self, sql, data):
        '''
        插入、修改、删除
        :param sql:
        :param data: [("root","123456"),("lhf","12356"),("eee","156")]
        :return:
        '''
        try:
            cur = self.get_cur()
            # cur.execute('insert into user (name,password) value (?,?)', (name, password))
            res = cur.executemany(sql, data)
            self.con.commit() # 提交except Exception as e:
            cur.close()
            self.con_close()
            print('数据库查询出错：', e)
        cur.close()
        return effectRow

    def con_close(self):
        self.con.close()

if __name__ == '__main__':
    # 获取数据库配置文件路径
    db_path = os.path.join(os.path.dirname(os.path.dirname(os.path.realpath(__file__))), 'conf', "application.yaml")
    db = MyMysql(db_path, '测试数据库')
    db.get_connection()
    print(db.search('''select 1 from dual'''))
    db.con_close()