python中的sqlite查询只使用对象将最后一行写入文件

Question

首先。。。在过去的几个月里，我对Python还是个新手，到现在为止，它一直都很顺利。但我在这里被难住了，我差点把我的头撞破显示器。你知道吗

当我运行这个脚本时，我只得到写入文件的最后一行数据，而我需要的是所有的数据行都以class部分的格式写入。你知道吗

卷_小时.db至少有多行，但只有最后一行正在写入。 这是我的剧本：

    from vlist import VLIST

import sqlite3
import decimal
import os
import sys
import uuid

VERSION = "oops"
DEVICE_SOFTWARE_VERSION = "OOPS"
FILENAME = "VHOURS.txt"
conn = sqlite3.connect("VOL_HOURS.db")






def fromVolunteers():
    conn = sqlite3.connect("VOL_HOURS.db")


with conn:

    cur = conn.cursor()
    cur.execute("SELECT BOB, DAVE, CAROL, ANDY, CARL, DANNY, CHERYL, CYNTHIA, TARA, SCOTT, ASHLEY, CRYSTAL FROM VOLUNTEERS")
    rows = cur.fetchall()




for row in rows:
    bob = row[0] 
    dave = row[1]
    carol = row[2]
    andy= row[3]
    carl = row[4]
    danny = row [5]
    cheryl = row [6]
    cynthia = row [7]
    tara = row [8]
    scott = row [9]
    ashley = row [10]
    crystal = row [11]



def main():
    fromVolunteers()
    testOutput = open(FILENAME, "w+")

    vlist = VLIST()
    vlist.setBob(bob)
    vlist.setDave(dave)
    vlist.setCarol(carol)
    vlist.setAndy(andy)
    vlist.setCarl(carl)
    vlist.setDanny(danny)
    vlist.setCheryl(cheryl)
    vlist.setCynthia(cynthia)
    vlist.setTara(tara)
    vlist.setScott(scott)
    vlist.setAshley(ashley)
    vlist.setCrystal(crystal)

    vlist.dump_object(testOutput)

    testOutput.flush()
    testOutput.close()
cur.close()
conn.close()

if __name__ == "__main__":
    sys.exit(main())

从中提取的类文件是：

class VLIST:

    def __init__(self):
        self.bob = ""
        self.dave = ""
        self.carol = ""
        self.andy = ""
        self.carl = ""
        self.danny = ""
        self.cheryl = ""
        self.cynthia = ""
        self.tara = ""
        self.scott = ""
        self.ashley = ""
        self.crystal = ""

    def setBob(self,bob):
        self.bob = bob
        return

    def setDave(self,dave):
        self.dave = dave
        return

    def setCarol(self,carol):
        self.carol = carol
        return

    def setAndy(self,andy):
        self.andy = andy
        return

    def setCarl(self,carl):
        self.carl = carl
        return

    def setDanny(self,danny):
        self.danny = danny
        return

    def setCheryl(self,cheryl):
        self.cheryl = cheryl
        return

    def setCynthia(self,cynthia):
        self.cynthia = cynthia
        return

    def setTara(self,tara):
        self.tara = tara
        return

    def setScott(self,scott):
        self.scott = scott
        return

    def setAshley(self,ashley):
        self.ashley = ashley
        return

    def setCrystal(self,crystal):
        self.crystal = crystal
        return

    def dump_object(self,testOutput):
        testOutput.write("VLIST,"+self.bob+","+self.dave+","+self.carol+","+self.andy+","+self.carl+","+self.danny+","+self.cheryl+","+self.cynthia+","+self.tara+","+self.scott+","+self.ashley+","+self.crystal+","+"\n")

我事先道歉，如果这是混乱的，就像我说的，我是新来的。谢谢你抽出时间。你知道吗

Answer 1

在迭代for row in rows:中，您只是覆盖变量bob、dave等的前一个值。因此，在迭代结束时，这些变量只有最后一个值。你知道吗

从fromVolunteers()中删除迭代。此函数只应设置rows变量，并将迭代放在main函数中：

import sqlite3
import decimal
import os
import sys
import uuid

VERSION = "oops"
DEVICE_SOFTWARE_VERSION = "OOPS"
FILENAME = "VHOURS.txt"
conn = sqlite3.connect("VOL_HOURS.db")

def fromVolunteers():
    conn = sqlite3.connect("VOL_HOURS.db")

    with conn:
        cur = conn.cursor()
        cur.execute("SELECT BOB, DAVE, CAROL, ANDY, CARL, DANNY, CHERYL, CYNTHIA, TARA, SCOTT, ASHLEY, CRYSTAL FROM VOLUNTEERS")
        rows = cur.fetchall()
def main():
    fromVolunteers()
    testOutput = open(FILENAME, "w+")

    for row in rows:
        vlist = VLIST()
        vlist.setBob(row[0])
        vlist.setDave(row[1])
        vlist.setCarol(row[2])
        vlist.setAndy(row[3])
        vlist.setCarl(row[4])
        vlist.setDanny(row[5])
        vlist.setCheryl(row[6])
        vlist.setCynthia(row[7])
        vlist.setTara(row[8])
        vlist.setScott(row[9])
        vlist.setAshley(row[10])
        vlist.setCrystal(row[11])
        vlist.dump_object(testOutput)

testOutput.flush()
testOutput.close()
cur.close()
conn.close()