Format string with multiple parameters so that MySQL can proces them

问题

I want to know how I can format a string that is returned by the API so that Mysql can process it.

This is the string my API returns: bad_string = "History,Romance,Business & Money"

Attempt 1:

cursor.execute("SELECT * FROM book WHERE scrape_category IN (%s) ORDER BY RAND() LIMIT 15", bad_string)

Returns this message:

Traceback (most recent call last):
  File "C:\PATH", line 23, in <module>
    cursor.execute("SELECT * FROM book WHERE scrape_category IN (%s) ORDER BY RAND() LIMIT 15", bad_string)
  File "C:\PATH\AppData\Roaming\Python\Python37\site-packages\mysql\connector\cursor_cext.py", line 259, in execute
    "Not all parameters were used in the SQL statement")
mysql.connector.errors.ProgrammingError: Not all parameters were used in the SQL statement

Attempt 2:

bad_string_2 = "'Romance', 'History', 'Business & Money'"

cursor.execute("SELECT * FROM book WHERE scrape_category IN (%s) ORDER BY RAND() LIMIT 15", bad_string_2)

Returns this message:

Traceback (most recent call last):
  File "C:PATH", line 21, in <module>
    cursor.execute("SELECT * FROM book WHERE scrape_category IN (%s) ORDER BY RAND() LIMIT 15", bad_string_2)
  File "C:\PATH\AppData\Roaming\Python\Python37\site-packages\mysql\connector\cursor_cext.py", line 246, in execute
    prepared = self._cnx.prepare_for_mysql(params)
  File "C:\PATH\AppData\Roaming\Python\Python37\site-packages\mysql\connector\connection_cext.py", line 520, in prepare_for_mysql
    raise ValueError("Could not process parameters")
ValueError: Could not process parameters

This works:

cursor.execute("SELECT * FROM book WHERE scrape_category IN ('Romance', 'History', 'Business & Money') ORDER BY RAND() LIMIT 15")

The query works when i do this:

cursor.execute("SELECT * FROM book WHERE scrape_category IN ('Romance', 'History', 'Business & Money') ORDER BY RAND() LIMIT 15")

How do I format the string and make MySQL return results?

回答1:

Try with some like this :

filter ="History,Romance,Business & Money".split(',')
sqlcommand = "SELECT * FROM book WHERE scrape_category IN ({0})".format(
    ', '.join(['%s'] * len(filter)))
print(sqlcommand)
cursor.execute(sqlcommand, filter)