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如何使用django批量添加到数据库功能

iVaibhav • 5 年前 • 1648 次点击  

我试图从应用程序的文本文件转储中向django的pgsql数据库添加大约40-50k行以进行数据处理

以下是我的功能

def populate_backup_db(dumpfile):
    sensordata=sensorrecords()  **** This is the Model
    start_time = time.time()
    file= open(dumpfile)
    filedata = file.readlines()
    endcount=len(filedata)
    i=0
    imagecount=0
    while i<endcount:
        lineitem = split_entry(filedata[i])
        if (lineitem[0]== "HEADER"):
            imagecount=imagecount+1
            sensordata.Sensor          = lineitem[1]
            sensordata.Date1           = lineitem[2]
            sensordata.Date2           = lineitem[3]
            sensordata.Version         = lineitem[4]  
            sensordata.Proxyclient     = lineitem[8]
            sensordata.Triggerdate     = ctodatetime(lineitem[13])
            sensordata.Compression     = lineitem[16]
            sensordata.Encryption      = lineitem[17]
            sensordata.Fragments       = lineitem[21]
            sensordata.Pbit            = lineitem[37]
            sensordata.BlockIntFT      = lineitem[38]
            sensordata.OriginServer   =  lineitem[56]
            sensordata.save()
        i=i+1
    elapsed_time = time.time() - start_time
    print(imagecount ,'entries saved to database from ',dumpfile,'. Time Taken is ',elapsed_time,' seconds.')
    file.close()

将所有数据保存到数据库大约需要2-3分钟。 这个Dumpfile可能会增加大小,如果要使用这个函数,可能需要几分钟的时间将所有数据保存到数据库中。

如何从DIP文件中提取所有数据,然后将其全部保存到数据库中。

我看到一个名为bulk_create()的django方法

bulk_create()¶

    bulk_create(objs, batch_size=None, ignore_conflicts=False)¶

此方法以有效的方式将提供的对象列表插入数据库(通常只有一个查询,不管有多少对象):

>>> Entry.objects.bulk_create([
...     Entry(headline='This is a test'),
...     Entry(headline='This is only a test'),
... ])

这个例子似乎是手动添加条目,我使用的函数是运行一个循环,直到获取所有条目,并在进程中保存。

如何循环运行?我要替换吗? sensordata.save() 具有 some_list.append(sensordata)

在循环结束后,做一个

sensordata.objects.bulk_create(some_list) 

我编辑了代码,将对象附加到一个列表中,然后在最后执行大容量更新,如下所示

def populate_backup_db(dumpfile):
    sensordata=sensorrecords()  **** This is the Model
    datalist =[]
    start_time = time.time()
    file= open(dumpfile)
    filedata = file.readlines()
    endcount=len(filedata)
    i=0
    imagecount=0
    while i<endcount:
        lineitem = split_entry(filedata[i])
        if (lineitem[0]== "HEADER"):
            imagecount=imagecount+1
            sensordata.Sensor          = lineitem[1]
            sensordata.Date1           = lineitem[2]
            sensordata.Date2           = lineitem[3]
            sensordata.Version         = lineitem[4]  
            sensordata.Proxyclient     = lineitem[8]
            sensordata.Triggerdate     = ctodatetime(lineitem[13])
            sensordata.Compression     = lineitem[16]
            sensordata.Encryption      = lineitem[17]
            sensordata.Fragments       = lineitem[21]
            sensordata.Pbit            = lineitem[37]
            sensordata.BlockIntFT      = lineitem[38]
            sensordata.OriginServer   =  lineitem[56]
            datalist.append(sensordata)
        i=i+1
    elapsed_time = time.time() - start_time
    print(imagecount ,'entries saved to database from ',dumpfile,'. Time Taken is ',elapsed_time,' seconds.')
sensordata.objects.bulk_create(datalist)    
file.close()

这将在下面引发一个错误

Traceback:

File "C:\Python\Python36\lib\site-packages\django\core\handlers\exception.py" in inner
  34.             response = get_response(request)

File "C:\Python\Python36\lib\site-packages\django\core\handlers\base.py" in _get_response
  126.                 response = self.process_exception_by_middleware(e, request)

File "C:\Python\Python36\lib\site-packages\django\core\handlers\base.py" in _get_response
  124.                 response = wrapped_callback(request, *callback_args, **callback_kwargs)

File "C:\Python\Python36\lib\site-packages\django\contrib\auth\decorators.py" in _wrapped_view
  21.                 return view_func(request, *args, **kwargs)

File "C:\Users\va\eclipse-workspace\prod\home\views.py" in process_data
  68.             get_backup_data()

File "C:\Users\va\eclipse-workspace\prod\home\process.py" in get_backup_data
  8.     populate_backup_db('c:\\users\\va\\desktop\\vsp\\backupdata_server.txt')

File "C:\Users\va\eclipse-workspace\prod\home\process.py" in populate_backup_db
  122.     sensordata.objects.bulk_create(datalist)

File "C:\Python\Python36\lib\site-packages\django\db\models\manager.py" in __get__
  176.             raise AttributeError("Manager isn't accessible via %s instances" % cls.__name__)

Exception Type: AttributeError at /process_data/
Exception Value: Manager isn't accessible via sensorrecords instances
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