先创建连接

import pymysql
 
connection = None
 
try:
    # 建立数据库连接
    connection = pymysql.connect(
        host='localhost',
        user='root',
        password='root',
        database='mydatabase',
        autocommit=True #设置自动提交
    )
 
    #游标对象
    cursor = connection.cursor()
 
 
except Exception as e:
    print(e)
finally:
    if connection:
        connection.close()

执行select查询操作

    #执行查询语句
    cursor.execute('select * from users')
 
    #获取查询的所有结果
    result = cursor.fetchall()
    print(result,type(result)) #  <class 'tuple'>
 
    for row in result:
        print(row)

执行insert插入操作

执行修改操作，需要通过Connection对象调用commit()方法确认提交，或者构造方法里面，autocommit设置Ture，自动提交

    #执行插入操作
    cursor.execute("insert into users values (null,'王五','wangwu@163.com',25,now(),'13664447879')")
    #获取主键
    print("主键id=",connection.insert_id()) #主键id= 3
    #确认提交
    connection.commit()
 
 
  #设置自动提交
 
    # 建立数据库连接
    connection = pymysql.connect(
        host='localhost',
        user='root',
        password='root',
        database='mydatabase',
        autocommit=True #设置自动提交
    )
    
      #执行插入操作
    cursor.execute("insert into users values (null,'赵六','zhaoliu@163.com',25,now(),'13664447879')")
    #获取主键
    print("主键id=",connection.insert_id()) #主键id= 3
    # #确认提交
    # connection.commit()

执行update操作

执行update操作，与insert操作类似

    #执行update更新操作
    cursor.execute("update users set age = 20 where id = 3 ")
    # #确认提交
    # connection.commit()

执行delete操作

    #执行delete更新操作
    cursor.execute("delete from users where id = 3 ")
    # #确认提交
    # connection.commit()