Question

我在这段代码中找不到错误：

sql = "INSERT INTO diff (val) VALUES (%s)"
test = '99'
mycursor.execute(sql, test)

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 '%s)' at line 1

有人可以向我解释吗？预先感谢！

Answer 1

如果可以描述所使用的数据库连接器，将有所帮助，但是您可以尝试以下操作：

如果该值是字符串，请尝试用引号将％s包裹起来

"INSERT INTO diff (val) VALUES ('%s')"

您可能需要使execute函数的第二个参数为元组，即

mycursor.execute(sql, (test,))

您的连接器可能还支持关键字参数

mycursor.execute("INSERT INTO diff (:val)", {'val': '99})

Answer 2

我在设备上遇到了同样的错误。我用
测试了直接SQL 插入diff（val）值（'99'）; 起作用了。

当我按照https://stackoverflow.com/users/6837068/james-wu的建议使用''时，错误停止，但是插入将插入0，直到将列更改为varchar，然后插入了'％s'而不是'99'。

我发现还有另一种分配变量的方法。

有关更多信息，请参见https://dev.mysql.com/doc/connector-python/en/connector-python-example-cursor-transaction.html。

示例代码如下。

#!/usr/bin/env python

import mysql.connector # pip install mysql-connector-python 
from mysql.connector import errorcode

try:
  connection = mysql.connector.connect(user='root', host='localhost',database='stackoverflow_53346780',use_pure=True)
  cursor = connection.cursor()
  #https://dev.mysql.com/doc/connector-python/en/connector-python-example-cursor-transaction.html
  sql = "INSERT INTO diff (val) VALUES (%(val)s) ;"
  test = {'val':'99'}
  cursor.execute(sql, test)
  connection.commit()
  cursor.close()
except mysql.connector.Error as err:
  if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
    print("Something is wrong with your user name or password")
  elif err.errno == errorcode.ER_BAD_DB_ERROR:
    print("Database does not exist")
  else:
    print(err)
else:
  connection.close()

结果

select * from diff ;

1   99
4   0
5   0
6   %s
7   99
8   99

Python上的SQL语法不正确

2 个答案: