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>night
   Name>
  <Type>esriFieldTypeString Type> <IsNullable>true IsNullable> <Length>4 Length> <Precision>0 Precision> <Scale>0 Scale> <AliasName>day AliasName> <ModelName>night ModelName> <DefaultValue xsi:type="xs:string">afternoon DefaultValue>  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>/StreetInfo
   CatalogPath>
  <Name>StreetInfo Name> <MetadataRetrieved>true MetadataRetrieved> <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>esriDTTable DatasetType> <Versioned>false Versioned> <CanVersion>false CanVersion> <ConfigurationKeyword> ConfigurationKeyword> <HasOID>true HasOID> <OIDFieldName>OBJECTID OIDFieldName> <Fields xsi:type='esri:Fields'> <FieldArray xsi:type='esri:ArrayOfField'> <Field xsi:type='esri:Field'> <Name>OBJECTID Name> <Type>esriFieldTypeOID Type> <IsNullable>false IsNullable> <Length>4 Length> <Precision>0 Precision> <Scale>0 Scale> <Required>true Required> <Editable>false Editable> <DomainFixed>true DomainFixed> <AliasName>OBJECTID AliasName> <ModelName>OBJECTID ModelName>  Field> <Field xsi:type='esri:Field'> <Name>Name Name> <Type>esriFieldTypeString Type> <IsNullable>true IsNullable> <Length>50 Length> <Precision>0 Precision> <Scale>0 Scale> <AliasName>Name AliasName> <ModelName>Name ModelName> <DefaultValue xsi:type='xs:string'> DefaultValue>  Field> <Field xsi:type='esri:Field'> <Name>StreetType Name> <Type>esriFieldTypeInteger Type> <IsNullable>true IsNullable> <Length>4 Length> <Precision>0 Precision> <Scale>0 Scale> <AliasName>StreetType AliasName> <ModelName>StreetType ModelName> <DefaultValue xsi:type='xs:double'>1 DefaultValue>  Field> <Field xsi:type='esri:Field'> <Name>Width Name> <Type>esriFieldTypeDouble Type> <IsNullable>true IsNullable> <Length>8 Length> <Precision>0 Precision> <Scale>0 Scale> <AliasName>Width AliasName> <ModelName>Width ModelName> <DefaultValue xsi:type='xs:double'>25.0 DefaultValue>  Field> <Field xsi:type='esri:Field'> <Name>LastPaved Name> <Type>esriFieldTypeDate Type> <IsNullable>true IsNullable> <Length>8 Length> <Precision>0 Precision> <Scale>0 Scale> <AliasName>LastPaved AliasName> <ModelName>LastPaved ModelName> <DefaultValue xsi:type='xs:dateTime'>2000-01-01T00:00:00 DefaultValue>  Field>  FieldArray>  Fields> <Indexes xsi:type='esri:Indexes'> <IndexArray xsi:type='esri:ArrayOfIndex'> <Index xsi:type='esri:Index'> <Name>FDO_OBJECTID Name> <IsUnique>true IsUnique> <IsAscending>true IsAscending> <Fields xsi:type='esri:Fields'> <FieldArray xsi:type='esri:ArrayOfField'> <Field xsi:type='esri:Field'> <Name>OBJECTID Name> <Type>esriFieldTypeOID Type> <IsNullable>false IsNullable> <Length>4 Length> <Precision>0 Precision> <Scale>0 Scale> <Required>true Required> <Editable>false Editable> <DomainFixed>true DomainFixed> <AliasName>OBJECTID AliasName> <ModelName>OBJECTID ModelName>  Field>  FieldArray>  Fields>  Index>  IndexArray>  Indexes> <CLSID>{7A566981-C114-11D2-8A28-006097AFF44E} CLSID> <EXTCLSID> EXTCLSID> <RelationshipClassNames xsi:type='esri:Names'> RelationshipClassNames> <AliasName>TestTable AliasName> <ModelName> ModelName> <HasGlobalID>false HasGlobalID> <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>StreetTypeIdx
   Name>
  <IsUnique>false IsUnique> <IsAscending>true IsAscending> <Fields xsi:type='esri:Fields'> <FieldArray xsi:type='esri:ArrayOfField'> <Field xsi:type='esri:Field'> <Name>StreetType Name> <Type>esriFieldTypeSmallInteger Type> <IsNullable>false IsNullable> <Length>2 Length> <Precision>0 Precision> <Scale>0 Scale> <Required>true Required> <Editable>false Editable> <DomainFixed>true DomainFixed> <AliasName>StreetType AliasName> <ModelName>StreetType ModelName>  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 three
   SubtypeName>
  <SubtypeCode>99 SubtypeCode> <FieldInfos xsi:type="esri:ArrayOfSubtypeFieldInfo"> <SubtypeFieldInfo xsi:type="esri:SubtypeFieldInfo"> <FieldName>percentComplete FieldName> <DomainName>sampleRangeDomain DomainName> <DefaultValue xsi:type="xs:double">56 DefaultValue>  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。