Python-MySQL ：删除查询中变量值周围的单引号 while 运行 db.execute(str, vars)

Question

我是运行这个码

    def details(self, dbsettings, payload):
        res = None
        with UseDatabase(dbsettings) as db:
            sql = "select * from %(tablename)s where userid = %(userid)s"
            result = db.run_query_vals(sql, payload)
            res = result.fetchall()
        return res

但出现错误

SQLError: 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''statuser' where userid = '14'' at line 1

传递的参数是：

sql = "select * from %(tablename)s where userid = %(userid)s"
payload = {'tablename' : 'statuser', 'userid' : 14}

据我所知，传递给 MySQL 的查询是按照

select * from 'statuser' where userid = '14'

这是我得到错误的地方； table 名称不应包含在引号中。如何在没有 quotes/make 反引号的情况下包含名称？

（我不想硬编码 table 名称 - 这是一个变量，在 class 创建期间根据不同的参数进行初始化）。有什么帮助吗？

Answer 1

您可以使用 python 中的字符串中的 .format():

def details(self, dbsettings, payload):
    res = None
    with UseDatabase(dbsettings) as db:
        sql = "select * from {tablename} where userid = {userid}"
        sql = sql.format(**payload)
        # result = db.run_query_vals(sql, payload) # Method to run query
        res = result.fetchall()
    return res

Answer 2

我在pymysql中遇到了同样的问题，找到了解决方案：

重写class'pymysql.connections.Connection'中的转义方法，明显是在你的字符串周围添加了“'”。

不知道对你的情况是否有帮助，只是分享一个可行的方法

类似问题：

这是我的代码：

from pymysql.connections import Connection, converters


class MyConnect(Connection):
    def escape(self, obj, mapping=None):
        """Escape whatever value you pass to it.

        Non-standard, for internal use; do not use this in your applications.
        """
        if isinstance(obj, str):
            return self.escape_string(obj)  # by default, it is :return "'" + self.escape_string(obj) + "'"
        if isinstance(obj, (bytes, bytearray)):
            ret = self._quote_bytes(obj)
            if self._binary_prefix:
                ret = "_binary" + ret
            return ret
        return converters.escape_item(obj, self.charset, mapping=mapping)


config = {'host':'', 'user':'', ...}
conn = MyConnect(**config)
cur = conn.cursor()

Python-MySQL ：删除查询中变量值周围的单引号 while 运行 db.execute(str, vars)

Python-MySQL : removing single quotes around variable values in query while running db.execute(str, vars)

mysql-python

python-3.x