AttributeQueryExpression Class

Artikkeli
11/28/2016

Applies To: Dynamics 365 (online), Dynamics 365 (on-premises), Dynamics CRM 2016, Dynamics CRM Online

Defines a complex query to retrieve attribute metadata for entities retrieved using an EntityQueryExpression

Namespace: Microsoft.Xrm.Sdk.Metadata.Query
Assembly: Microsoft.Xrm.Sdk (in Microsoft.Xrm.Sdk.dll)

Inheritance Hierarchy

System.Object
Microsoft.Xrm.Sdk.Metadata.Query.MetadataQueryBase
Microsoft.Xrm.Sdk.Metadata.Query.MetadataQueryExpression
Microsoft.Xrm.Sdk.Metadata.Query.AttributeQueryExpression

Syntax

[DataContractAttribute(Name = "AttributeQueryExpression", Namespace = "https://schemas.microsoft.com/xrm/2011/Metadata/Query")]
public sealed class AttributeQueryExpression : MetadataQueryExpression

<DataContractAttribute(Name := "AttributeQueryExpression", Namespace := "https://schemas.microsoft.com/xrm/2011/Metadata/Query")>
Public NotInheritable Class AttributeQueryExpression
    Inherits MetadataQueryExpression

Constructors

	Name	Description
	AttributeQueryExpression()	Initializes a new instance of the AttributeQueryExpression class.

Properties

	Name	Description
	Criteria	Gets or sets the filter criteria for the metadata query.(Inherited from MetadataQueryExpression.)
	ExtensionData	Gets or sets the structure that contains extra data.(Inherited from MetadataQueryBase.)
	Properties	Gets or sets the properties to be returned by the query.(Inherited from MetadataQueryExpression.)

Methods

	Name	Description
	Equals(Object)	(Inherited from Object.)
	GetHashCode()	(Inherited from Object.)
	GetType()	(Inherited from Object.)
	ToString()	(Inherited from Object.)

Remarks

The following example shows the use of an AttributeQueryExpression to retrieve entity metadata.


//A condition expresson to return optionset attributes
MetadataConditionExpression[] optionsetAttributeTypes = new MetadataConditionExpression[] { 
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.Picklist),
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.State),
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.Status),
new MetadataConditionExpression("AttributeType", MetadataConditionOperator.Equals, AttributeTypeCode.Boolean)
};

//A filter expression to apply the optionsetAttributeTypes condition expression
MetadataFilterExpression AttributeFilter = new MetadataFilterExpression(LogicalOperator.Or);
AttributeFilter.Conditions.AddRange(optionsetAttributeTypes);

//A Properties expression to limit the properties to be included with attributes
MetadataPropertiesExpression AttributeProperties = new MetadataPropertiesExpression() { AllProperties = false };
AttributeProperties.PropertyNames.Add("OptionSet");
AttributeProperties.PropertyNames.Add("AttributeType");


//An entity query expression to combine the filter expressions and property expressions for the query.
EntityQueryExpression entityQueryExpression = new EntityQueryExpression()
{

 Criteria = EntityFilter,
 Properties = EntityProperties,
 AttributeQuery = new AttributeQueryExpression()
 {
  Criteria = AttributeFilter,
  Properties = AttributeProperties
 },
 LabelQuery = labelQuery

};

//Retrieve the metadata for the query without a ClientVersionStamp
RetrieveMetadataChangesResponse initialRequest = getMetadataChanges(entityQueryExpression, null, DeletedMetadataFilters.OptionSet);

Thread Safety

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Jaa