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檢索最後插入的主鍵
我建立與GeoDjango內置的應用程序，我有以下問題：GeoDjango內置：從LayerMapping
我需要從一個GPX文件中讀取的軌道數據，並將這些數據應該存儲在一個模型MultiLineStringField領域。 這應該在管理界面，用戶上傳
我試圖做到這一點，即數據從應分配給MultiLineStringField文件抓起一個GPX文件發生，而其他領域應該得到的值表格。
我的模式是：
class GPXTrack(models.Model):
nome = models.CharField("Nome", blank = False, max_length = 255)
slug = models.SlugField("Slug", blank = True)
# sport natura arte/cultura
tipo = models.CharField("Tipologia", blank = False, max_length = 2, choices=TIPOLOGIA_CHOICES)
descrizione = models.TextField("Descrizione", blank = True)
gpx_file = models.FileField(upload_to = 'uploads/gpx/')
track = models.MultiLineStringField(blank = True)
objects = models.GeoManager()
published = models.BooleanField("Pubblicato")
rel_files = generic.GenericRelation(MyFiles)
#publish_on = models.DateTimeField("Pubblicare il", auto_now_add = True)
created = models.DateTimeField("Created", auto_now_add = True)
updated = models.DateTimeField("Updated", auto_now = True)
class Meta:
#verbose_name = "struttura'"
#verbose_name_plural = "strutture"
ordering = ['-created']
def __str__(self):
return str(self.nome)
def __unicode__(self):
return '%s' % (self.nome)
def put(self):
self.slug = sluggy(self.nome)
key = super(Foresta, self).put()
# do something after save
return key
而在admin.py文件我已覆蓋保存方法如下：
from django.contrib.gis import admin
from trails.models import GPXPoint, GPXTrack
from django.contrib.contenttypes import generic
from django.contrib.gis.gdal import DataSource
#from gpx_mapping import GPXMapping
from django.contrib.gis.utils import LayerMapping
from django.template import RequestContext
import tempfile
import os
import pprint
class GPXTrackAdmin(admin.OSMGeoAdmin):
list_filter = ('tipo', 'published')
search_fields = ['nome']
list_display = ('nome', 'tipo', 'published', 'gpx_file')
inlines = [TrackImagesInline, TrackFilesInline]
prepopulated_fields = {"slug": ("nome",)}
def save_model(self, request, obj, form, change):
"""When creating a new object, set the creator field.
"""
if 'gpx_file' in request.FILES:
# Get
gpxFile = request.FILES['gpx_file']
# Save
targetPath = tempfile.mkstemp()[1]
destination = open(targetPath, 'wt')
for chunk in gpxFile.chunks():
destination.write(chunk)
destination.close()
#define fields of interest for LayerMapping
track_point_mapping = {'timestamp' : 'time',
'point' : 'POINT',
}
track_mapping = {'track' : 'MULTILINESTRING'}
gpx_file = DataSource(targetPath)
mytrack = LayerMapping(GPXTrack, gpx_file, track_mapping, layer='tracks')
mytrack.save()
#remove the temp file saved
os.remove(targetPath)
orig = GPXTrack.objects.get(pk=mytrack.pk)
#assign the parsed values from LayerMapping to the appropriate Field
obj.track = orig.track
obj.save()
據我所知：
- LayerMapping不能用於更新字段，但僅用於保存新字段
- I （在上面的代碼，即：mytrack.track）不能訪問LayerMapping對象的特定字段，其值分配到模型字段（即obj.track）在model_save方法
- 我不能檢索主最後保存LayerMapping對象的鍵（即在上面的代碼：mytrack.pk），以便與在LayerMapping.mapping
沒有映射的形式爲現場傳遞的值來更新它我能那麼呢？！？！