This page gives a few examples of how XML constructs are mapped to OGR layers and fields by the GMLAS driver.
Schema | Document | OGR layers | Comments |
---|---|---|---|
<schema xmlns="http://www.w3.org/2001/XMLSchema"> <element name="MyFeature"> <complexType> <sequence> <element name="name" type="string"/> </sequence> <attribute name="id" type="ID" use="required"/> <attribute name="attr" type="string"/> </complexType> </element> </schema> |
<MyFeature id="my_id" attr="attr_value"> <name>my_name</name> </MyFeature> |
Layer name: MyFeature Geometry: None id: String (0.0) NOT NULL attr: String (0.0) name: String (0.0) NOT NULL OGRFeature(MyFeature):1 id (String) = my_id attr (String) = attr_value name (String) = my_name |
Element with attributes and sub-elements of simple type and maximum cardinality of 1. |
<schema xmlns="http://www.w3.org/2001/XMLSchema"> <element name="MyFeature"> <complexType> <sequence> <element name="str_array" type="string" maxOccurs="2"/> <element name="dt_array" type="dateTime" maxOccurs="unbounded"/> </sequence> <attribute name="id" type="ID" use="required"/> </complexType> </element> </schema> |
<MyFeature id="my_id"> <str_array>first string</str_array> <str_array>second string</str_array> <dt_array>2016-09-24T15:31:00Z</dt_array> <dt_array>2016-09-24T15:32:00Z</dt_array> </MyFeature> |
Layer name: MyFeature Geometry: None id: String (0.0) NOT NULL str_array: StringList (0.0) NOT NULL OGRFeature(MyFeature):1 id (String) = my_id str_array (StringList) = (2:first string,second string) Layer name: MyFeature_dt_array Geometry: None ogr_pkid: String (0.0) NOT NULL parent_id: String (0.0) NOT NULL value: DateTime (0.0) OGRFeature(MyFeature_dt_array):1 ogr_pkid (String) = my_id_dt_array_1 parent_id (String) = my_id value (DateTime) = 2016/09/24 15:31:00+00 OGRFeature(MyFeature_dt_array):2 ogr_pkid (String) = my_id_dt_array_2 parent_id (String) = my_id value (DateTime) = 2016/09/24 15:32:00+00 |
Case of array and child layer |
<schema xmlns="http://www.w3.org/2001/XMLSchema"> <element name="MyFeature"> <complexType> <sequence> <element name="identifier"> <complexType> <sequence> <element name="name"> <complexType> <simpleContent> <extension base="string"> <attribute name="lang" type="string"/> </extension> </simpleContent> </complexType> </element> <element name="namespace" type="string" minOccurs="0"/> </sequence> </complexType> </element> </sequence> <attribute name="id" type="ID" use="required"/> </complexType> </element> </schema> |
<MyFeature id="my_id"> <identifier> <name lang="en">my_name</name> <namespace>baz</namespace> </identifier> </MyFeature> |
Layer name: MyFeature Geometry: None id: String (0.0) NOT NULL identifier_name_lang: String (0.0) identifier_name: String (0.0) identifier_namespace: String (0.0) OGRFeature(MyFeature):1 id (String) = my_id identifier_name_lang (String) = en identifier_name (String) = my_name identifier_namespace (String) = baz |
Case of nested element, that can be folded into main layer. Use of an attribute on a sub-element. |
<schema xmlns:myns="http://myns" targetNamespace="http://myns" elementFormDefault="qualified" xmlns="http://www.w3.org/2001/XMLSchema"> <element name="AbstractFeature" abstract="true"/> <element name="FeatureCollection"> <complexType><sequence> <element ref="myns:AbstractFeature" maxOccurs="unbounded"/> </sequence></complexType> </element> <complexType name="namesType"> <sequence> <element ref="myns:name" maxOccurs="unbounded"/> </sequence> </complexType> <element name="MyFeature" substitutionGroup="myns:AbstractFeature"> <complexType><sequence> <element name="names" type="myns:namesType"/> </sequence> <attribute name="id" type="ID" use="required"/> </complexType> </element> <element name="MyFeature2" substitutionGroup="myns:AbstractFeature"> <complexType><sequence> <element name="names" type="myns:namesType"/> </sequence> <attribute name="id" type="ID" use="required"/> </complexType> </element> <element name="name"> <complexType><sequence> <element name="name" type="string"/> <element name="lang" type="string"/> </sequence></complexType> </element> </schema> |
<FeatureCollection xmlns="http://myns"> <MyFeature id="my_id"> <names> <name> <name>name</name> <lang>en</lang> </name> <name> <name>nom</name> <lang>fr</lang> </name> </names> </MyFeature> <MyFeature2 id="my_id2"> <names> <name> <name>nom2</name> <lang>fr</lang> </name> </names> </MyFeature2> </FeatureCollection> |
Layer name: name OGRFeature(name):1 ogr_pkid (String) = _name_1 name (String) = name lang (String) = en OGRFeature(name):2 ogr_pkid (String) = _name_2 name (String) = nom lang (String) = fr OGRFeature(name):3 ogr_pkid (String) = _name_3 name (String) = nom2 lang (String) = fr Layer name: MyFeature OGRFeature(MyFeature):1 id (String) = my_id Layer name: MyFeature2 OGRFeature(MyFeature2):1 id (String) = my_id2 Layer name: MyFeature_names_name_name OGRFeature(MyFeature_names_name_name):1 occurrence (Integer) = 1 parent_pkid (String) = my_id child_pkid (String) = _name_1 OGRFeature(MyFeature_names_name_name):2 occurrence (Integer) = 2 parent_pkid (String) = my_id child_pkid (String) = _name_2 Layer name: MyFeature2_names_name_name OGRFeature(MyFeature2_names_name_name):1 occurrence (Integer) = 1 parent_pkid (String) = my_id2 child_pkid (String) = _name_3 |
Case of a common element "name" referenced by 2 layers "MyFeature" and "MyFeature1". The links are established through the junction layers "MyFeature_names_name_name" and "MyFeature2_names_name_name". |