我使用gdal ruby来解析ESRI ShapeFiles,就像这个演示中一样。我想遍历所有特性,以便将字段值推送到数据库中。但是,我找不到如何检索每个字段的名称,我需要它来匹配数据库列。到目前为止,我只能使用字段的字段索引,例如:
dataset = Gdal::Ogr.open(filename)
number_of_layers = dataset.get_layer_count
number_of_layers.times do |layer_index|
layer = dataset.get_layer(layer_index)
layer.get_feature_count.times do |feature_index|
feature = layer.get_feature(feature_index)
feature.get_field_count.times do |field_index|
field_value = feature.get_field(field_index)
# How can I find out the name of the field?
puts "Value = #{field_value} for unknown field name"
end
end
end
我用irb检查了可用的方法,并查看了API文档。我好像在找错误的术语。
看看OGR API本身,我认为您需要通过特性。GetDefnRef,以获取功能定义,然后对相关字段执行.GetFieldDefn,最后执行.GetNameRef。。。?
...
feature.get_field_count.times do |field_index|
defn_ref = feature.get_defn_ref
field_defn = defn_ref.get_field_defn(field_index)
field_name = field_defn.get_name
field_value = feature.get_field(field_index)
puts "Value = #{field_value} for field named #{field_name}"
end
...
ds = ogr.Open(filename, 1)
layer = ds.GetLayer()
for i in range(len(layer.schema)):
print(layer.schema[i].name)