封装一个mysql增删改查的方法

这是一个基于Python的MySQL增删改查方法的示例：

import mysql.connector

# 创建数据库连接
mydb = mysql.connector.connect(
  host="localhost",
  user="yourusername",
  password="yourpassword",
  database="yourdatabase"
)

# 定义查询方法
def select_data(table, columns, condition=None):
    mycursor = mydb.cursor()

    if condition:
        sql = "SELECT {} FROM {} WHERE {}".format(columns, table, condition)
    else:
        sql = "SELECT {} FROM {}".format(columns, table)

    mycursor.execute(sql)
    result = mycursor.fetchall()

    return result

# 定义插入方法
def insert_data(table, columns, values):
    mycursor = mydb.cursor()

    sql = "INSERT INTO {} ({}) VALUES ({})".format(table, columns, values)

    mycursor.execute(sql)
    mydb.commit()

    print(mycursor.rowcount, "record inserted.")

# 定义更新方法
def update_data(table, set_values, condition):
    mycursor = mydb.cursor()

    sql = "UPDATE {} SET {} WHERE {}".format(table, set_values, condition)

    mycursor.execute(sql)
    mydb.commit()

    print(mycursor.rowcount, "record(s) affected.")

# 定义删除方法
def delete_data(table, condition):
    mycursor = mydb.cursor()

    sql = "DELETE FROM {} WHERE {}".format(table, condition)

    mycursor.execute(sql)
    mydb.commit()

    print(mycursor.rowcount, "record(s) deleted.")

使用示例：

# 查询数据
result = select_data("customers", "*", "name = 'John'")
for row in result:
    print(row)

# 插入数据
insert_data("customers", "name, address", "'John', 'Highway 21'")

# 更新数据
update_data("customers", "address = 'Park Lane 38'", "name = 'John'")

# 删除数据
delete_data("customers", "address = 'Highway 21'")