python连接mysql数据库

安装

安装 pip3 install pymysql
python3 import pymysql
python2 import MySQLdb

操作sql

增

import pymysql

conn = pymysql.connect(
    host='192.168.0.103',
    port=3306,
    user='root',
    password='123',
    database='xing',
    charset='utf8'
)
cursor = conn.cursor()  # 获取一个光标
sql = 'insert into userinfo (user,pwd) values (%s,%s);'

name = 'wuli'
pwd = '123456789'
cursor.execute(sql, [name, pwd])
conn.commit()

last_id = cursor.lastrowid
print("最后一条数据的ID是:", last_id)

cursor.close()
conn.close()

删

import pymysql

# 建立连接
conn = pymysql.connect(
    host="192.168.0.103",
    port=3306,
    user="root",
    password="123",
    database="xing",
    charset="utf8"
)
# 获取一个光标
cursor = conn.cursor()
# 定义将要执行的SQL语句
sql = "delete from userinfo where user=%s;"
name = "june"
# 拼接并执行SQL语句
cursor.execute(sql, [name])
# 涉及写操作注意要提交
conn.commit()
# 关闭连接

cursor.close()
conn.close()

改

import pymysql

# 建立连接
conn = pymysql.connect(
    host="192.168.0.103",
    port=3306,
    user="root",
    password="123",
    database="xing",
    charset="utf8"
)
# 获取一个光标
cursor = conn.cursor()
# 定义将要执行的SQL语句
sql = "update userinfo set pwd=%s where user=%s;"
# 拼接并执行SQL语句
cursor.execute(sql, ["july", "july"])

# 涉及写操作注意要提交
conn.commit()

# 关闭连接
cursor.close()
conn.close()

查

import pymysql

conn = pymysql.connect(
    host='192.168.0.103',
    port=3306,
    user='root',
    password='123',
    database='xing',
    charset='utf8'
)
# 获取一个光标
cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)  # 返回字典数据类型

# 定义将要执行的sql语句
sql = 'select user,pwd from userinfo;'
# 拼接并执行sql语句
cursor.execute(sql)

# 取到查询结果
ret1 = cursor.fetchone()  # 取一条
ret2 = cursor.fetchmany(3)  # 取三条
ret3 = cursor.fetchone()  # 取一条

cursor.close()
conn.close()

print(ret1)
print(ret2)
print(ret3)
# 可以获取指定数量的数据
cursor.fetchmany(3)
# 光标按绝对位置移动1
cursor.scroll(1, mode="absolute")
# 光标按照相对位置(当前位置)移动1
cursor.scroll(1, mode="relative")