pymysql的使用

一: 安装pymysql

pip3 install pymysql

二: 查询操作

import pymysql

# 打开数据库连接
db = pymysql.connect(host='localhost', user='root', password='123456', db='userinfo', port=3306)

# 使用cursor()方法获取操作游标
cur = db.cursor()

#1, 查询操作
# 编写sql,查询语句 s_info 对应的表名
sql = "select * from s_info"
try:
    cur.execute(sql)    # 执行sql语句

    # results = cur.fetchall()

    # 获取一行
    # result_one = cur.fetchone()
    # print(result_one)

    # 获取多个
    result_many = cur.fetchmany(3)
    print(result_many)
    # print(results) # 返回所有的数据一元组套元组的形式
    # print("id", "name", "pwd")
    # #遍历结果
    # for row in results:
    #     id = row[0]
    #     name = row[1]
    #     password = row[2]
    #     print(id, name, password)
except Exception as e:
    raise e
finally:
    db.close()

三: 插入操作

import pymysql

#2 插入操作
db = pymysql.connect(host='localhost', user='root', password='123456', port=3306, db='userinfo')

# 使用游标
cur = db.cursor()

sql_insert =  "insert into s_info(name, pwd) values('egon', '456')"

try:
    cur.execute(sql_insert)

    db.commit()
except Exception as e:
    db.rollback()
    raise e
finally:
    cur.close()
    db.close()

四: 修改操作

import pymysql

# 获取数据库
db = pymysql.connect(host='localhost', user='root', password='123456', db='userinfo', port=3306)

# 获取游标
cur = db.cursor()

# sql改语句
sql = "update s_info set name=%s where id=7"
try:
    cur.execute(sql, "egon")
    db.commit()
except Exception as e:
    raise e
finally:
    cur.close()
    db.close()

五: 删除操作

import pymysql

db = pymysql.connect(host='localhost', user='root', password='123456', port=3306, db='userinfo')

cur = db.cursor()

sql = "delete from s_info where id=1"

try:
    cur.execute(sql)
    db.commit()
except Exception as e:
    raise e
finally:
    cur.close()
    db.close()