LinkEntity Class

Artikkeli
10/20/2016

Applies To: Dynamics CRM 2015

Specifies the links between multiple entity types used in creating complex queries.

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

Inheritance Hierarchy

System.Object
Microsoft.Xrm.Sdk.Query.LinkEntity

Syntax

[DataContractAttribute(Name = "LinkEntity", Namespace = "https://schemas.microsoft.com/xrm/2011/Contracts")]
public sealed class LinkEntity : IExtensibleDataObject

[DataContractAttribute(Name = "LinkEntity", Namespace = "https://schemas.microsoft.com/xrm/2011/Contracts")]
public ref class LinkEntity sealed : IExtensibleDataObject

[<Sealed>]
[<DataContractAttribute(Name = "LinkEntity", Namespace = "https://schemas.microsoft.com/xrm/2011/Contracts")>]
type LinkEntity = 
    class
        interface IExtensibleDataObject
    end

<DataContractAttribute(Name := "LinkEntity", Namespace := "https://schemas.microsoft.com/xrm/2011/Contracts")>
Public NotInheritable Class LinkEntity
    Implements IExtensibleDataObject

Constructors

	Name	Description
	LinkEntity()	Initializes a new instance of the LinkEntity class.
	LinkEntity(String, String, String, String, JoinOperator)	Initializes a new instance of the LinkEntity class setting the required properties.

Properties

	Name	Description
	Columns	Gets or sets the column set.
	EntityAlias	Gets or sets the alias for the entity.
	ExtensionData	Gets or sets the structure that contains extra data.
	JoinOperator	Gets or sets the join operator.
	LinkCriteria	Gets or sets the complex condition and logical filter expressions that filter the results of the query.
	LinkEntities	Gets the links between multiple entity types.
	LinkFromAttributeName	Gets or sets the logical name of the attribute of the entity that you are linking from.
	LinkFromEntityName	Gets or sets the logical name of the entity that you are linking from.
	LinkToAttributeName	Gets or sets the logical name of the attribute of the entity that you are linking to.
	LinkToEntityName	Gets or sets the logical name of the entity that you are linking to.

Methods

	Name	Description
	AddLink(String, String, String)	Adds a link, setting the link to entity name, the link from attribute name and the link to attribute name.
	AddLink(String, String, String, JoinOperator)	Adds a link setting the link to entity name, the link from attribute name, the link to attribute name, and the join operator.
	Equals(Object)	(Inherited from Object.)
	GetHashCode()	(Inherited from Object.)
	GetType()	(Inherited from Object.)
	ToString()	(Inherited from Object.)

Examples

q = new QueryExpression();
q.EntityName = "account";
q.ColumnSet = new ColumnSet();
q.ColumnSet.Columns.Add("name");

q.LinkEntities.Add(new LinkEntity("account", "contact", "primarycontactid", "contactid", JoinOperator.Inner));
q.LinkEntities[0].Columns.AddColumns("firstname", "lastname");
q.LinkEntities[0].EntityAlias = "temp";

q.Criteria = new FilterExpression();
q.Criteria.AddCondition("accountnumber", ConditionOperator.Equal, accountNumber);
q.Orders.Add(new OrderExpression("name", OrderType.Descending));
q.Distinct = true;
EntityCollection ec = this.Context.Proxy.RetrieveMultiple(q);

Log.Assert(ec.Entities.Count == 3, "Expected 3 entities, received {0}", ec.Entities.Count);
Log.Assert((string)ec.Entities[0]["name"] == "SdkAccount3", "First Entity should be SdkAccount3");
Log.Assert((string)ec.Entities[1]["name"] == "SdkAccount2", "First Entity should be SdkAccount2");
Log.Assert((string)ec.Entities[2]["name"] == "SdkAccount1", "First Entity should be SdkAccount1");
Log.Assert((string)((AliasedValue)ec.Entities[0]["temp.firstname"]).Value == (string)contact["firstname"], "Expected {0} Got {1}", contact["firstname"], ec.Entities[0]["temp.firstname"]);
Log.Assert((string)((AliasedValue)ec.Entities[1]["temp.lastname"]).Value == (string)contact["lastname"], "Expected {0} Got {1}", contact["lastname"], ec.Entities[1]["temp.lastname"]);

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