在python中添加动态表名

Question

在给定的查询中，我试图将表名作为用户的输入：

import MySQLdb
import csv
conn=MySQLdb.connect("localhost","root","","graphdata")

c=conn.cursor()
a= raw_input("Enter the table name")
sql='''SELECT distinct sku FROM %s_management'''
c.execute(sql,str(a))
rows=c.fetchall()

file=open('mine.csv','a+')

for eachRow in rows:
    print eachRow
    a=eachRow
    file.write(str(a)+"\n")

file.close()

我想要的是编译器应该像

Enter table name:

我应该输入表名

Enter table name: inventory

它应该在查询中连接起来：

sql='''SELECT distinct sku FROM inventory_management'''

但到目前为止，我收到了这些错误：

 c.execute(sql,str(a))
  File "C:\Python27\lib\site-packages\MySQLdb\cursors.py", line 198, in execute
    query = query % args
TypeError: not all arguments converted during string formatting


  File "change.py", line 7, in <module>
    sql='''SELECT distinct sku FROM %s'''(a)
TypeError: 'str' object is not callable


    c.execute("SELECT distinct sku FROM %s_management")(a)
  File "C:\Python27\lib\site-packages\MySQLdb\cursors.py", line 219, in execute
    self.errorhandler(self, exc, value)
  File "C:\Python27\lib\site-packages\MySQLdb\connections.py", line 38, in defau
lterrorhandler
    raise errorvalue
_mysql_exceptions.ProgrammingError: (1064, "You have an error in your SQL syntax
; check the manual that corresponds to your MySQL server version for the right s
yntax to use near '%s_management' at line 1")

Answer 1

使用format()的字符串

>>> sql='SELECT distinct sku FROM {}_management'.format(a)
>>> sql
>>> 'SELECT distinct sku FROM inventory_management'

然后您只需将查询传递给光标：

c.execute(sql)

Answer 2

我不建议这样做，因为它会带来安全问题，但您可以这样做 -

c.execute(sql % str(a))

或者在 python 中使用任何其他类型的字符串格式化程序来更改表名。