FileGDB API for linux 学习系列之四，XML Schema of Geodatabase

从很早以前(至少从ArcGIS9.2包括9.2)ESRI的桌面产品就提供了将空间数据导成XML文件的功能，如下图，





可以选择只将数据库的schema的结构导出，也可以选择将数据也一并导出。到现在的FileGDB API继续沿用这一架构。在FileGDB API中提供了很多

操作Schema内容的函数，如：

操作Domain的函数：

CreateDomain(const std::string &domainDef) //创建域

AlterDomain(const std::string &domainDef) //改变域

DeleteDomain(const std::string &domainDef) //删除域

操作表的函数：

AddField(std::string &fieldDef) //添加字段

AlterField(std::string &fieldDef)//改变字段

DeleteField(std::string &fieldDef)//删除字段

操作子类的函数:

CreateSubtype(std::string &subtypeDef) //创建子类

AlterSubtype(std::string &subtypeDef)//改变子类

DeleteSubtype(std::string &subtypeDef)//删除子类

等等，所有的牵扯到Schema中对象的定义，修改，删除等函数的参数，都是XML格式，当然这些XML格式并不能随便写，必须得按照ESRI的规范

进行书写，具体规范在FileGDB API的doc文件中的XML_Schema_of_Geodatabase-3.pdf中有详细的介绍。以下是常用的几种对象的定义规范：

1. 字段的定义





以下是XML表示的Field例子：

<Field xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xs='http://www.w3.org/2001/XMLSchema'

xmlns:esri='http://www.esri.com/schemas/ArcGIS/10.1' xsi:type='esri:Field'>
<Name>nightName>
<Type>esriFieldTypeStringType>
<IsNullable>trueIsNullable>
<Length>4Length>
<Precision>0Precision>
<Scale>0Scale>
<AliasName>dayAliasName>
<ModelName>nightModelName>
<DefaultValue xsi:type="xs:string">afternoonDefaultValue>
Field>

其中Type元素定义了字段的类型，FileGDB API一共提供了13种数据类型，分别是

esriFieldTypeSmallInteger

esriFieldTypeInteger

esriFieldTypeSingle

esriFieldTypeDouble

esriFieldTypeString

esriFieldTypeDate

esriFieldTypeOID

esriFieldTypeGeometry

esriFieldTypeBlob

esriFieldTypeRaster

esriFieldTypeGUID

esriFieldTypeGlobalID

esriFieldTypeXML

2. 表的定义

XML例子如下：

xml version="1.0" encoding="UTF-8"?>
<esri:DataElement xmlns:esri='http://www.esri.com/schemas/ArcGIS/10.1'

xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xs='http://www.w3.org/2001/XMLSchema' xsi:type='esri:DETable'>
<CatalogPath>/StreetInfoCatalogPath>
<Name>StreetInfoName>
<MetadataRetrieved>trueMetadataRetrieved>
<Metadata xsi:type='esri:XmlPropertySet'>
<XmlDoc>
<?xml version="1.0"?>
<metadata xml:lang="en"><Esri><CreaDate>20101215</CreaDate><CreaTime>13025800</CreaTime><ArcGISFormat>1.0</ArcGISFormat><SyncOnce>TRUE</SyncOnce></Esri></metadata>
XmlDoc>
Metadata>
<DatasetType>esriDTTableDatasetType>
<Versioned>falseVersioned>
<CanVersion>falseCanVersion>
<ConfigurationKeyword>ConfigurationKeyword>
<HasOID>trueHasOID>
<OIDFieldName>OBJECTIDOIDFieldName>
<Fields xsi:type='esri:Fields'>
<FieldArray xsi:type='esri:ArrayOfField'>
<Field xsi:type='esri:Field'>
<Name>OBJECTIDName>
<Type>esriFieldTypeOIDType>
<IsNullable>falseIsNullable>
<Length>4Length>
<Precision>0Precision>
<Scale>0Scale>
<Required>trueRequired>
<Editable>falseEditable>
<DomainFixed>trueDomainFixed>
<AliasName>OBJECTIDAliasName>
<ModelName>OBJECTIDModelName>
Field>
<Field xsi:type='esri:Field'>
<Name>NameName>
<Type>esriFieldTypeStringType>
<IsNullable>trueIsNullable>
<Length>50Length>
<Precision>0Precision>
<Scale>0Scale>
<AliasName>NameAliasName>
<ModelName>NameModelName>
<DefaultValue xsi:type='xs:string'>DefaultValue>
Field>
<Field xsi:type='esri:Field'>
<Name>StreetTypeName>
<Type>esriFieldTypeIntegerType>
<IsNullable>trueIsNullable>
<Length>4Length>
<Precision>0Precision>
<Scale>0Scale>
<AliasName>StreetTypeAliasName>
<ModelName>StreetTypeModelName>
<DefaultValue xsi:type='xs:double'>1DefaultValue>
Field>
<Field xsi:type='esri:Field'>
<Name>WidthName>
<Type>esriFieldTypeDoubleType>
<IsNullable>trueIsNullable>
<Length>8Length>
<Precision>0Precision>
<Scale>0Scale>
<AliasName>WidthAliasName>
<ModelName>WidthModelName>
<DefaultValue xsi:type='xs:double'>25.0DefaultValue>
Field>
<Field xsi:type='esri:Field'>
<Name>LastPavedName>
<Type>esriFieldTypeDateType>
<IsNullable>trueIsNullable>
<Length>8Length>
<Precision>0Precision>
<Scale>0Scale>
<AliasName>LastPavedAliasName>
<ModelName>LastPavedModelName>
<DefaultValue xsi:type='xs:dateTime'>2000-01-01T00:00:00DefaultValue>
Field>
FieldArray>
Fields>
<Indexes xsi:type='esri:Indexes'>
<IndexArray xsi:type='esri:ArrayOfIndex'>
<Index xsi:type='esri:Index'>
<Name>FDO_OBJECTIDName>
<IsUnique>trueIsUnique>
<IsAscending>trueIsAscending>
<Fields xsi:type='esri:Fields'>
<FieldArray xsi:type='esri:ArrayOfField'>
<Field xsi:type='esri:Field'>
<Name>OBJECTIDName>
<Type>esriFieldTypeOIDType>
<IsNullable>falseIsNullable>
<Length>4Length>
<Precision>0Precision>
<Scale>0Scale>
<Required>trueRequired>
<Editable>falseEditable>
<DomainFixed>trueDomainFixed>
<AliasName>OBJECTIDAliasName>
<ModelName>OBJECTIDModelName>
Field>
FieldArray>
Fields>
Index>
IndexArray>
Indexes>
<CLSID>{7A566981-C114-11D2-8A28-006097AFF44E}CLSID>
<EXTCLSID>EXTCLSID>
<RelationshipClassNames xsi:type='esri:Names'>RelationshipClassNames>
<AliasName>TestTableAliasName>
<ModelName>ModelName>
<HasGlobalID>falseHasGlobalID>
<GlobalIDFieldName>GlobalIDFieldName>
<RasterFieldName>RasterFieldName>
<ExtensionProperties xsi:type='esri:PropertySet'>
<PropertyArray xsi:type='esri:ArrayOfPropertySetProperty'>PropertyArray>
ExtensionProperties>
<ControllerMemberships xsi:type='esri:ArrayOfControllerMembership'>ControllerMemberships>
esri:DataElement>

3. 索引的定义





XML例子表示：

<esri:Index xsi:type='esri:Index' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'

xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:esri='http://www.esri.com/schemas/ArcGIS/10.1'>
<Name>StreetTypeIdxName>
<IsUnique>falseIsUnique>
<IsAscending>trueIsAscending>
<Fields xsi:type='esri:Fields'>
<FieldArray xsi:type='esri:ArrayOfField'>
<Field xsi:type='esri:Field'>
<Name>StreetTypeName>
<Type>esriFieldTypeSmallIntegerType>
<IsNullable>falseIsNullable>
<Length>2Length>
<Precision>0Precision>
<Scale>0Scale>
<Required>trueRequired>
<Editable>falseEditable>
<DomainFixed>trueDomainFixed>
<AliasName>StreetTypeAliasName>
<ModelName>StreetTypeModelName>
Field>
FieldArray>
Fields>
esri:Index>

SubType的XML的结构图:





XML的例子：

<esri:Subtype xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xs=http://www.w3.org/2001/XMLSchema

xmlns:esri="http://www.esri.com/schemas/ArcGIS/10.1" xsi:type="esri:Subtype">
<SubtypeName>subtype threeSubtypeName>
<SubtypeCode>99SubtypeCode>
<FieldInfos xsi:type="esri:ArrayOfSubtypeFieldInfo">
<SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo">
<FieldName>percentCompleteFieldName>
<DomainName>sampleRangeDomainDomainName>
<DefaultValue xsi:type="xs:double">56DefaultValue>
SubtypeFieldInfo>
FieldInfos>
esri:Subtype>

先举着这些例子吧，居然别的类型，可以查看pdf文件。