如何将字符串列格式化为整型列？

import mysql.connector

# 连接到数据库
cnx = mysql.connector.connect(user='username', password='password', host='localhost', database='database_name')
cursor = cnx.cursor()

# 创建新的整型列
alter_table_query = "ALTER TABLE table_name ADD new_column_name INT"
cursor.execute(alter_table_query)

# 查询字符串列
select_query = "SELECT string_column_name FROM table_name"
cursor.execute(select_query)
result = cursor.fetchall()

# 遍历字符串列并将其转换为整数
for row in result:
    string_value = row[0]
    try:
        int_value = int(string_value)
    except ValueError:
        int_value = None
    
    # 将转换后的整数值插入新的整型列
    update_query = "UPDATE table_name SET new_column_name = %s WHERE string_column_name = %s"
    cursor.execute(update_query, (int_value, string_value))

# 提交更改并关闭连接
cnx.commit()
cursor.close()
cnx.close()