sql:limit-field 和 sql:limit-value (SQLXML 4.0)

XML 大容量加载按照定义处理 sql:limit-fieldsql:limit-value 批注。 有关详细信息,请参阅 使用 sql:limit-field 筛选值和 sql:limit-value (SQLXML 4.0)

例如,假定一个数据库包含以下各表:

  • Customer (CustomerID, CompanyName)

  • Addresses(CustomerID、StreetAddress、AddressType)

客户可以具有多个地址,并且每个地址都具有一个关联的地址类型(如发货地址或帐单地址)。

现在,请考虑在以下带批注的 XSD 架构中指定的这些表的此 XML 视图:

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"  
            xmlns:sql="urn:schemas-microsoft-com:mapping-schema">  
<xsd:annotation>  
  <xsd:appinfo>  
    <sql:relationship name="CustAddr"  
        parent="Customer"  
        parent-key="CustomerID"  
        child="Address"  
        child-key="CustomerID" />  
  </xsd:appinfo>  
</xsd:annotation>  
  
  <xsd:element name="Customer" sql:relation="Customer" >  
   <xsd:complexType>  
        <xsd:attribute name="CustomerID"   type="xsd:int" />   
        <xsd:attribute name="CompanyName"  type="xsd:string" />  
        <xsd:attribute name="BillTo"   
                       type="xsd:string"   
                       sql:relation="Address"   
                       sql:field="StreetAddress"  
                       sql:limit-field="AddressType"  
                       sql:limit-value="billing"  
                       sql:relationship="CustAddr" >  
        </xsd:attribute>  
        <xsd:attribute name="ShipTo"   
                       type="xsd:string"   
                       sql:relation="Address"   
                       sql:field="StreetAddress"  
                       sql:limit-field="AddressType"  
                       sql:limit-value="shipping"  
                       sql:relationship="CustAddr" >  
        </xsd:attribute>  
    </xsd:complexType>  
  </xsd:element>  
</xsd:schema>  

收到此架构和 XML 数据时,XML 大容量加载将为 BillTo 属性指定的值插入到 CustAddress 表的 StreetAddress 列,并将“billing”值插入到 AddressType 列。

类似地,XML 大容量加载将为 ShipTo 属性指定的值插入到 StreetAddress 列,并将“shipping”值插入到 AddressType 列。

测试工作示例

  1. 将在该示例中提供的架构另存为 SampleSchema.xml。

  2. 创建以下表:

    CREATE TABLE Customer(  
                     CustomerID     int         PRIMARY KEY,  
                     CompanyName    varchar(20) NOT NULL)  
    GO  
    CREATE TABLE Address(  
                      CustomerID     int        FOREIGN KEY REFERENCES   
                                                 Customer(CustomerID),   
                      StreetAddress  varchar(50),  
                      AddressType    varchar(10))  
    GO  
    
  3. 将下面的示例数据另存为 SampleXMLData.xml:

    <Customer CustomerID="1111" CompanyName="Sean Chai" City="NY"   
                 BillTo="111 Maple (Billing) "   
                 ShipTo="111 Maple (Shipping)" />  
    <Customer CustomerID="1112" CompanyName="Dont Know" City="LA"   
                 BillTo="222 Spruce (Billing)"   
                 ShipTo="222 Spruce (Shipping)" />  
    
  4. 若要执行 XML 大容量加载,请将此 Microsoft Visual Basic Scripting Edition (VBScript) 示例保存并执行为Sample.vbs:

    set objBL = CreateObject("SQLXMLBulkLoad.SQLXMLBulkload.4.0")  
    objBL.ConnectionString = "provider=SQLOLEDB;data source=localhost;database=tempdb;integrated security=SSPI"  
    objBL.ErrorLogFile = "c:\error.log"  
    objBL.XMLFragment = True  
    objBL.CheckConstraints=True  
    objBL.Execute "c:\SampleSchema.xml", "c:\SampleXMLData.xml"  
    set objBL=Nothing  
    

这是等效的 XDR 架构:

<?xml version="1.0" ?>  
<Schema xmlns="urn:schemas-microsoft-com:xml-data"  
        xmlns:dt="urn:schemas-microsoft-com:datatypes"  
        xmlns:sql="urn:schemas-microsoft-com:xml-sql">  
  
<ElementType name="Customer" sql:relation="Customer" >  
    <AttributeType name="CustomerID" />  
    <AttributeType name="CompanyName" />  
    <AttributeType name="BillTo" />  
    <AttributeType name="ShipTo" />  
  
    <attribute type="CustomerID" />  
    <attribute type="CompanyName" />  
    <attribute type="BillTo"   
                sql:limit-field="AddressType"  
                sql:limit-value="billing"  
                sql:field="StreetAddress"  
                sql:relation="Address" >  
                <sql:relationship   
                        key="CustomerID"  
                        key-relation="Customer"  
                        foreign-relation="Address"  
                        foreign-key="CustomerID" />  
    </attribute>  
    <attribute type="ShipTo"   
                sql:limit-field="AddressType"  
                sql:limit-value="shipping"  
                sql:field="StreetAddress"  
                sql:relation="Address" >  
                <sql:relationship   
                     key="CustomerID"  
                     key-relation="Customer"  
                     foreign-relation="Address"  
                     foreign-key="CustomerID" />  
    </attribute>  
</ElementType>  
</Schema>