Data Type Conversion Error while trying to dynamic

问题:

I'm trying to populate the 1st row(i.e. the column names) from an excel sheet to the ms-access database, but it's giving me 'Data type conversion Error(3421)'. Any idea why this is happening ?

from comtypes.client import CreateObject
from xlrd import open_workbook,cellname
import os
from comtypes.gen import Access

access = CreateObject('Access.Application')    

DBEngine = access.DBEngine

db = DBEngine.CreateDatabase('test.mdb', Access.DB_LANG_GENERAL)

excel_file = open_workbook('test_excel_file.xlsx')
work_sheet = excel_file.sheet_by_index(0)

db.BeginTrans()
db.Execute("CREATE TABLE MY_TABLE (ID Text)")

for row_index in range(0, 1):
    for col_index in range(0, work_sheet.ncols):
        cell_value = work_sheet.cell(row_index,col_index).value
        db.Execute("ALTER TABLE MY_TABLE ADD COLUMN %s", cell_value)

db.CommitTrans()
db.Close()

Error:

Traceback (most recent call last):
File "My_DB_Code.py", line 21, in <module>
db.Execute("ALTER TABLE MY_TABLE ADD COLUMN %s", cell_value)
_ctypes.COMError: (-2146824867, None, (u'Data type conversion error.', u'DAO.Dat
abase', u'jeterr40.chm', 5003421, None))

回答1:

A parameterized query allows parameters to be substituted for the values of a column, but not for table and column names themselves. You will need to use string formatting for that, as in

db.Execute("ALTER TABLE MY_TABLE ADD COLUMN [{0}] TEXT(50)".format(cell_value))