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。