sqlite3 + sqlalchemy迭代数据库添加错误 - python（战斗）

Question

我有9个xlsx文件，我想从中读取数据，并将每一行添加到数据库的表中。

以下是代码：

import sqlalchemy
import os
import csv
import sqlite3

from readData import *
from sqlalchemy import *
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base

#Change these
dbname = "TandWPODB2"

metadata = MetaData()
Base = declarative_base()
filePath = "CAM MIKE DATA\B2B\TEMPLE AND WEBSTER PO"
purchDirectory = os.path.abspath(os.path.join(filePath))
print purchDirectory

class TandWPurchaseOrder(Base):
    __tablename__ = 'tandwpurchaseorder'

    orderNum = Column(Integer)
    barcode = Column(String)
    skuNum = Column(String, primary_key=True)
    shipID = Column(String)
    description = Column(String)
    quantity = Column(Integer)
    costPrice = Column(String)
    totalCost = Column(String)
    agreedDeliveryDate = Column(String)
    colour = Column(String)
    material = Column(String)
    itemDims = Column(String)
    CoO = Column(String)  # what even is this?
    itemWeightEa = Column(String)
    shipWidth = Column(String)
    shipDepth = Column(String)
    shipHeight = Column(String)
    itemCubic = Column(String)
    totalCubic = Column(String)
    deadweight = Column(String)


def createDB(dbname):
    global dbEngine
    global dbSession

    dbEngine = create_engine('sqlite:///' + dbname, echo=False)
    #create Session
    Session = sessionmaker()
    Session.configure(bind=dbEngine)
    dbSession = Session()

    #create tables
    Base.metadata.create_all(dbEngine)
    print "db created"


def readPurchaseOrder(purchDirectory, session):
    wsList = readFiles(purchDirectory)
    wsRange = []
    headers = []
    # print type(wsList) #List
    # print(type(wsList[0]))
    #for i,ws in enumerate(wsList):
    for ws in wsList:
        #print type(ws)
        list1, list2 = readWs(ws)  # list1 = wsRange, list2 = headers
        wsRange.append(list1)
        headers.append(list2)
        # print headers[0]
        # print (wsRange)
        #wsRange[i(ws)][j][k] = k item in row j of table/book i
    # print(len(wsRange)) #9 = num pages
    # print(len(wsRange[0])) #changing = num rows
    # print(len(wsRange[0][0])) #20 = num item in row


    # for i = len(wsRange)
    for i in range(len(wsRange)):
        for j in range(len(wsRange[i])):
            TandWPurchOrder = TandWPurchaseOrder(
                                                orderNum = wsRange[i][j][0].value,
                                                barcode = wsRange[i][j][1].value,
                                                skuNum = wsRange[i][j][2].value,
                                                shipID = wsRange[i][j][3].value,
                                                description = wsRange[i][j][4].value,
                                                quantity = wsRange[i][j][5].value,
                                                costPrice = wsRange[i][j][6].value,
                                                totalCost = wsRange[i][j][7].value,
                                                agreedDeliveryDate = wsRange[i][j][8].value,
                                                colour = wsRange[i][j][9].value,
                                                material = wsRange[i][j][10].value,
                                                itemDims = wsRange[i][j][11].value,
                                                CoO = wsRange[i][j][12].value,  # what even is this?
                                                itemWeightEa = wsRange[i][j][13].value,
                                                shipWidth = wsRange[i][j][14].value,
                                                shipDepth = wsRange[i][j][15].value,
                                                shipHeight = wsRange[i][j][16].value,
                                                itemCubic = wsRange[i][j][17].value,
                                                totalCubic = wsRange[i][j][18].value,
                                                deadweight = wsRange[i][j][19].value,
                                                )

            dbSession.add(TandWPurchOrder)
    dbSession.commit()


createDB(dbname)
Base.metadata.create_all(dbEngine)
readPurchaseOrder(purchDirectory, dbSession)

我得到的错误是：

sqlalchemy.exc.IntegrityError: (sqlite3.IntegrityError) column skuNum is not unique [SQL: u'INSERT INTO tandwpurchaseorder

我对python和数据库很新，所以非常感谢任何帮助