Fóntais allmhairithe sonraí LayermappingLink to this heading#

SamplaLink to this heading#

1. Teastaíonn foinse sonraí le tacaíocht ó GDAL uait, cosúil le comhaid chruthach (anseo táimid ag úsáid comhad cruth polygon simplí, test_poly.shp, le trí ghné):

>>> from django.contrib.gis.gdal import DataSource
>>> ds = DataSource("test_poly.shp")
>>> layer = ds[0]
>>> print(layer.fields)  # Exploring the fields in the layer, we only want the 'str' field.
['float', 'int', 'str']
>>> print(len(layer))  # getting the number of features in the layer (should be 3)
3
>>> print(layer.geom_type)  # Should be 'Polygon'
Polygon
>>> print(layer.srs)  # WGS84 in WKT
GEOGCS["GCS_WGS_1984",
    DATUM["WGS_1984",
        SPHEROID["WGS_1984",6378137,298.257223563]],
    PRIMEM["Greenwich",0],
    UNIT["Degree",0.017453292519943295]]

1. Anois sainmhínímid ár samhail Django comhfhreagrach (déan cinnte go n-úsáidtear: djadmin: migrate):

   Code

   from django.contrib.gis.db import models
   
   
   class TestGeo(models.Model):
       name = models.CharField(max_length=25)  # corresponds to the 'str' field
       poly = models.PolygonField(srid=4269)  # we want our model in a different SRID
   
       def __str__(self):
           return "Name: %s" % self.name
   

2. Úsáid: aicme: LayerMapping chun na gnéithe go léir a bhaint agus iad a chur sa bhunachar sonraí:

>>> from django.contrib.gis.utils import LayerMapping
>>> from geoapp.models import TestGeo
>>> mapping = {
...     "name": "str",  # The 'name' model field maps to the 'str' layer field.
...     "poly": "POLYGON",  # For geometry fields use OGC name.
... }  # The mapping is a dictionary
>>> lm = LayerMapping(TestGeo, "test_poly.shp", mapping)
>>> lm.save(verbose=True)  # Save the layermap, imports the data.
Saved: Name: 1
Saved: Name: 2
Saved: Name: 3

Anseo, :class: LayerMapping d'athraigh na trí ghéiméadair ón gcomhaid cruth ina gcóras tagartha spásúil bunaidh (WGS84) go dtí an córas tagartha spásúil den tsamhail GeoDjango (NAD83). Mura sainmhínítear aon chóras tagartha spásúil don chiseal, bain úsáid as an eochairfhocal source_srs le a:class: ~django.contrib.gis.gdal.spatialReference chun réad ceann a shonrú.

Sraith Maping APILink to this heading#

class LayerMapping(model, data_source, mapping, layer=0, source_srs=None, encoding=None, transaction_mode='commit_on_success', transform=True, unique=True, using='default')Link to this definition#

Is iad seo a leanas na hargóintí agus na heochairfhocail a d'fhéadfaí a úsáid le linn rudaí Layermapping` a chur isteach.

FabhtcheartúLink to this heading#

OperationalError: (1153, "Got a packet bigger than 'max_allowed_packet' bytes")

max_allowed_packet = 10M