StringBuilder xmlString = new StringBuilder(
    "<QueryPacket xmlns='urn:Microsoft.Search.Query'>"
    + "<Query><SupportedFormats><Format revision='1'> urn:Microsoft.Search.Response.Document:Document"
    + "</Format></SupportedFormats><Context>"
    + " <QueryText language='en-US' type='FQL'>");
// this adds the search free form text 
xmlString.Append("Earth");
query.Append(
    "</QueryText></Context>"
    + "<Properties>"
    + "<Property name='Name'/>"
    + "<Property name='Department' />"
    + "<Property name='Property1' />"                
    + "<Property name='Property2' />"
    + "<Property name='Property3' />"
    + "<Property name='Property4' />"
    + "<Property name='Property5' />"
    + "</Properties>"
    + "<Where>"
    + "<IsNotNull><FieldRef Name='Name'></FieldRef></IsNotNull>"
    + "<And><IsNotNull><FieldRef Name='Property1'></FieldRef></IsNotNull></And>"
    + "</Where>"                                       
    + "</Query></QueryPacket>"
);
QueryServiceSoapClient.QueryEx(query)
我在 Name 和 Property1 列上获取空值/空值的数据。为什么哪里不工作?