建立链接
import pymysql
conn = pymysql.connect(
host='localhost',
user='root',
password='1111111',
port=3306,
database='demo_pymysql'
)
cursor = conn.cursor()
res = cursor.execute('select * from user;')
print(cursor.fetchall())
conn.close()
插入数据
import pymysql
conn = pymysql.connect(
host='localhost',
user='root',
password='22222',
port=3306,
database='demo_pymysql'
)
cursor = conn.cursor()
sql = """
insert into user(id, username, age, password) values(null, %s, %s, %s)
"""
username = 'dd'
age = 21
password = '123123'
cursor.execute(sql, (username, age, password))
conn.commit()
# 注意需要coomit后才会插入
res = cursor.execute('select * from user;')
print(cursor.fetchall())
conn.close()
查找数据
使用pymysql查询数据。可以使用fetch方法
1、fetchone():这个方法每次获取一条数据
2、fetchall():这个方法接收全部的返回值
3、fetchmany():这个方法可以返回指定条数的数据
import pymysql
conn = pymysql.connect(
host='localhost',
user='root',
password='',
port=3306,
database='demo_pymysql'
)
cursor = conn.cursor()
sql = """
select username, age from user where id > 2;
"""
cursor.execute(sql)
res = cursor.fetchmany(10)
print(res)
conn.close()
删除数据
sql = """
delete from user where id=3
"""
cursor.execute(sql)
conn.commit()
需要注意的是在执行删除语句后,需要commit才能生效
更新数据
sql = """
update user set username='luole' where id=1
"""
cursor.execute(sql)
conn.commit()
需要注意的是在执行更新语句后,需要commit才能生效
本文详细介绍如何使用PyMySQL库进行数据库连接、数据插入、查询、删除及更新操作,为Python开发者提供全面的数据库交互指南。
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