将Linq表达式转换为QueryExpression或FetchXML
我的最终目标是将linq表达式转换为获取xml。我打算在MS CRM 2011中为自定义网格使用fetch XML 从本文中,我可以将QueryExpression转换为FetchXML 但我不知道如何将Linq表达式转换为QueryExpression。当我说linq表达式时,我指的是IQueryable类型的对象 有没有人有过这样的经验或者知道怎么做将Linq表达式转换为QueryExpression或FetchXML,linq,dynamics-crm,fetchxml,Linq,Dynamics Crm,Fetchxml,我的最终目标是将linq表达式转换为获取xml。我打算在MS CRM 2011中为自定义网格使用fetch XML 从本文中,我可以将QueryExpression转换为FetchXML 但我不知道如何将Linq表达式转换为QueryExpression。当我说linq表达式时,我指的是IQueryable类型的对象 有没有人有过这样的经验或者知道怎么做 Cheers在LINQ表达式上调用ToString()应该返回FetchXML在LINQ表达式上调用ToString()应该返回FetchXM
Cheers在LINQ表达式上调用ToString()应该返回FetchXML在LINQ表达式上调用ToString()应该返回FetchXML您可以使用反射从
IQuerable
获取提供程序并调用其上的Translate方法来获取QueryExpression
下面是我正在使用的扩展方法:
public static QueryExpression ToQueryExpression(this IQueryable @this)
{
var provider = @this.Provider;
var translateMethod = provider.GetType().GetMethod("Translate");
var query = (QueryExpression)translateMethod.Invoke(provider, new object[] { @this.Expression });
return query;
}
如果您在C#中使用某种类型的动态包装器进行反射,您可以这样做:
public static QueryExpression ToQueryExpression(this IQueryable @this)
{
dynamic provider = ExposedObject.From(@this.Provider);
return provider.Translate(@this.Expression);
}
至于fetch,您需要使用
QueryExpression
,然后发出一个请求QueryExpressionToFetchXmlRequest
,该请求返回QueryExpressionToFetchXmlResponse
响应,该响应具有属性FetchXml
,您可以使用反射来获取QueryExpression
,从IQuerable
获取提供者并调用其上的Translate方法
下面是我正在使用的扩展方法:
public static QueryExpression ToQueryExpression(this IQueryable @this)
{
var provider = @this.Provider;
var translateMethod = provider.GetType().GetMethod("Translate");
var query = (QueryExpression)translateMethod.Invoke(provider, new object[] { @this.Expression });
return query;
}
如果您在C#中使用某种类型的动态包装器进行反射,您可以这样做:
public static QueryExpression ToQueryExpression(this IQueryable @this)
{
dynamic provider = ExposedObject.From(@this.Provider);
return provider.Translate(@this.Expression);
}
至于fetch,您需要使用
QueryExpression
,然后发出一个请求QueryExpressionToFetchXmlRequest
,该请求返回QueryExpressionToFetchXmlResponse
响应,该响应具有属性FetchXml
,所提供的解决方案不适用于Chielus提到的CRM2013 SDK程序集
对于CRM2013,您可以使用以下扩展方法:
public static class QueryProviderExtensions
{
public static QueryExpression ToQueryExpression<T>(this IQueryable<T> items)
{
var queryProvider = items.Provider;
var queryProviderType = queryProvider.GetType();
var listType = typeof(List<>);
var projectionType = queryProviderType.Assembly.GetType("Microsoft.Xrm.Sdk.Linq.QueryProvider+Projection");
var navigationSourceType = queryProviderType.Assembly.GetType("Microsoft.Xrm.Sdk.Linq.QueryProvider+NavigationSource");
var linkLookupType = queryProviderType.Assembly.GetType("Microsoft.Xrm.Sdk.Linq.QueryProvider+LinkLookup");
var linkLookupListType = listType.MakeGenericType(linkLookupType);
object projection = null;
object source = Activator.CreateInstance(navigationSourceType, new object[] { null, null });
object linkLookups = Activator.CreateInstance(linkLookupListType);
bool throwIfSequenceIsEmpty = false;
bool throwIfSequenceNotSingle = false;
object[] arguments = new object[6];
arguments[0] = items.Expression;
arguments[1] = throwIfSequenceIsEmpty;
arguments[2] = throwIfSequenceNotSingle;
arguments[3] = projection;
arguments[4] = source;
arguments[5] = linkLookups;
var getQueryExpressionMethod = queryProviderType.GetMethod("GetQueryExpression", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public, null, new[] {
typeof(Expression),
typeof(bool).MakeByRefType(),
typeof(bool).MakeByRefType(),
projectionType.MakeByRefType(),
navigationSourceType.MakeByRefType(),
linkLookupListType.MakeByRefType(),
}, null);
var queryExpression = (QueryExpression)getQueryExpressionMethod.Invoke(queryProvider, arguments);
return queryExpression;
}
public static string ToXml(this QueryExpression queryExpression, IOrganizationService service)
{
var request = new QueryExpressionToFetchXmlRequest { Query = queryExpression };
var response = (QueryExpressionToFetchXmlResponse)service.Execute(request);
return response.FetchXml;
}
}
详情如下:
提供的解决方案不适用于Chielus提到的CRM2013 SDK程序集 对于CRM2013,您可以使用以下扩展方法:
public static class QueryProviderExtensions
{
public static QueryExpression ToQueryExpression<T>(this IQueryable<T> items)
{
var queryProvider = items.Provider;
var queryProviderType = queryProvider.GetType();
var listType = typeof(List<>);
var projectionType = queryProviderType.Assembly.GetType("Microsoft.Xrm.Sdk.Linq.QueryProvider+Projection");
var navigationSourceType = queryProviderType.Assembly.GetType("Microsoft.Xrm.Sdk.Linq.QueryProvider+NavigationSource");
var linkLookupType = queryProviderType.Assembly.GetType("Microsoft.Xrm.Sdk.Linq.QueryProvider+LinkLookup");
var linkLookupListType = listType.MakeGenericType(linkLookupType);
object projection = null;
object source = Activator.CreateInstance(navigationSourceType, new object[] { null, null });
object linkLookups = Activator.CreateInstance(linkLookupListType);
bool throwIfSequenceIsEmpty = false;
bool throwIfSequenceNotSingle = false;
object[] arguments = new object[6];
arguments[0] = items.Expression;
arguments[1] = throwIfSequenceIsEmpty;
arguments[2] = throwIfSequenceNotSingle;
arguments[3] = projection;
arguments[4] = source;
arguments[5] = linkLookups;
var getQueryExpressionMethod = queryProviderType.GetMethod("GetQueryExpression", BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public, null, new[] {
typeof(Expression),
typeof(bool).MakeByRefType(),
typeof(bool).MakeByRefType(),
projectionType.MakeByRefType(),
navigationSourceType.MakeByRefType(),
linkLookupListType.MakeByRefType(),
}, null);
var queryExpression = (QueryExpression)getQueryExpressionMethod.Invoke(queryProvider, arguments);
return queryExpression;
}
public static string ToXml(this QueryExpression queryExpression, IOrganizationService service)
{
var request = new QueryExpressionToFetchXmlRequest { Query = queryExpression };
var response = (QueryExpressionToFetchXmlResponse)service.Execute(request);
return response.FetchXml;
}
}
详情如下:
我尝试了这个方法,但它只返回对象类型名称。我找到了对此的引用,但仅适用于CRM 4.0。我尝试了此操作,但它只返回对象类型名称。我找到了这方面的参考资料,但仅限于CRM 4.0。这在Dynamics CRM 2013中被打破。请参阅此博客文章以了解支持的替代方案:这在Dynamics CRM 2013中已被打破。有关受支持的备选方案,请参阅此博客: