Python处理mysql特殊字符的问题

有的时候我们会去扫表，然后拿出扫的结果再到另一张表里去查信息。比如下面一段

index_sql_str = "select ％s from user where ％s = ％d" ％ ("social_id", "user_id", u_id)
 db_cursor.execute(index_sql_str)
 rows = ['"' + row[0] + '"' for row in db_cursor.fetchall()]
 if len(rows) == 0:
   return None
 result = []
 sql_str = "select ％s user_detail where ％s in (％s)" ％ (",".join(user_third_column_name), "social_id", ",".join(rows))
 db_cursor.execute(sql_str)

常会有用％s或者+拼接query string的情况，这时候如果拿出来的键值带有'或''就会导致拼接出现问题。

可以考虑用format，即

>>> a = 'test"test'
>>> "insert into user {0}".format(a)
'insert into user test"test'
>>> b = "test'test"
>>> "insert into user {0} where {1} = x".format(a,b)
'insert into user test"test where test\'test = x'

如果大小写都包含会自己增加转义字符

补充拓展：基于python中写mysql关于like ％ 的问题

#@ 1 - 正常执行的mysql 语句为:
select * from RESIDENTIAL_AREA where RA_ID like 'HF-％'

#@ 2 - 在python 代码中为： 最后面的那个 ％ 需要4个％ 去代替（raid = HF-）
select_sql = ''' select * from RESIDENTIAL_AREA where RA_ID
 like '％s％％％％' ''' ％ (raid)

#@ 3 - python 代码中 输出结果为：print(select_sql)
select * from RESIDENTIAL_AREA where RA_ID like 'HF-％％'

来源：https://blog.csdn.net/weixin_41571449/article/details/79214702