QueryExpressionToFetchXmlRequest 类

应用到: CRM 2015 on-prem, CRM Online

Contains the data that is needed to convert a query, which is represented as a QueryExpression class, to its equivalent query, which is represented as FetchXML.

命名空间: Microsoft.Crm.Sdk.Messages
程序集: Microsoft.Crm.Sdk.Proxy (在 Microsoft.Crm.Sdk.Proxy.dll 中)

语法

声明
<DataContractAttribute(Namespace:="https://schemas.microsoft.com/crm/2011/Contracts")> _
Public NotInheritable Class QueryExpressionToFetchXmlRequest
    Inherits OrganizationRequest

[DataContractAttribute(Namespace="https://schemas.microsoft.com/crm/2011/Contracts")] 
public sealed class QueryExpressionToFetchXmlRequest : OrganizationRequest

示例

The following example shows how to use this message. For this sample to work correctly, you must be connected to the server to get an IOrganizationService interface. For the complete sample, see the link later in this topic.

// Build a query expression that we will turn into FetchXML.
var queryExpression = new QueryExpression()
{
    Distinct = false,
    EntityName = Contact.EntityLogicalName,
    ColumnSet = new ColumnSet("fullname", "address1_telephone1"),
    LinkEntities = 
        {
            new LinkEntity 
            {
                JoinOperator = JoinOperator.LeftOuter,
                LinkFromAttributeName = "parentcustomerid",
                LinkFromEntityName = Contact.EntityLogicalName,
                LinkToAttributeName = "accountid",
                LinkToEntityName = Account.EntityLogicalName,
                LinkCriteria = 
                {
                    Conditions = 
                    {
                        new ConditionExpression("name", ConditionOperator.Equal, "Litware, Inc.")
                    }
                }
            }
        },
    Criteria =
    {
        Filters = 
            {
                new FilterExpression
                {
                    FilterOperator = LogicalOperator.And,
                    Conditions = 
                    {
                        new ConditionExpression("address1_stateorprovince", ConditionOperator.Equal, "WA"),
                        new ConditionExpression("address1_city", ConditionOperator.In, new String[] {"Redmond", "Bellevue" , "Kirkland", "Seattle"}),
                        new ConditionExpression("createdon", ConditionOperator.LastXDays, 30),
                        new ConditionExpression("emailaddress1", ConditionOperator.NotNull)
                    },
                },
                new FilterExpression
                {
                    FilterOperator = LogicalOperator.Or,
                    Conditions =
                    {
                        new ConditionExpression("address1_telephone1", ConditionOperator.Like, "(206)%"),
                        new ConditionExpression("address1_telephone1", ConditionOperator.Like, "(425)%")
                    }
                }
            }
    }
};

// Run the query as a query expression.
EntityCollection queryExpressionResult =
    _serviceProxy.RetrieveMultiple(queryExpression);
Console.WriteLine("Output for query as QueryExpression:");
DisplayContactQueryResults(queryExpressionResult);

// Convert the query expression to FetchXML.
var conversionRequest = new QueryExpressionToFetchXmlRequest
{
    Query = queryExpression
};
var conversionResponse =
    (QueryExpressionToFetchXmlResponse)_serviceProxy.Execute(conversionRequest);

// Use the converted query to make a retrieve multiple request to Microsoft Dynamics CRM.
String fetchXml = conversionResponse.FetchXml;
var fetchQuery = new FetchExpression(fetchXml);
EntityCollection result = _serviceProxy.RetrieveMultiple(fetchQuery);

// Display the results.
Console.WriteLine("\nOutput for query after conversion to FetchXML:");
DisplayContactQueryResults(result);

备注

Message Availability

无论调用方是连接到服务器还是处于脱机状态，此消息都可正常工作。

Usage

Pass an instance of this class to the Execute method, which returns an instance of the QueryExpressionToFetchXmlResponse class.

Privileges and Access Rights

For a complete list of the required privileges, see QueryExpressionToFetchXml Privileges.

Notes for Callers

Use of the keyword distinct in query expressions is different from the FetchXML query language. When you map a query from Fetch to QueryExpression, you receive inconsistent results if you use the Distinct keyword in the FetchXML string.

继承层次结构

System.Object
   Microsoft.Xrm.Sdk.OrganizationRequest
    Microsoft.Crm.Sdk.Messages.QueryExpressionToFetchXmlRequest

线程安全性

此类型的所有公共静态（Visual Basic 中的 Shared）成员都是线程安全成员。不保证任何实例成员是线程安全成员。

平台

开发平台

Windows Vista、Windows Server 2003 和

目标平台

Windows Vista,Windows XP

Change History

另请参阅

参考

QueryExpressionToFetchXmlRequest 成员
Microsoft.Crm.Sdk.Messages 命名空间
QueryExpressionToFetchXmlResponse

其他资源

Create Queries to Retrieve Data
Page Large Result Sets with Query Expression and FetchXML
Build Queries with QueryExpression
FetchXML Schema
Sample: Convert Queries Between Fetch and Query Expression

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