像过滤器一样的 Mongodb 上的 Asp.net Core Odata

Question

我有一个 Asp.net Core 2.2 Odata 控制器，我需要在其中过滤具有“喜欢”功能的人的姓名。这出错了。 MongoDB 驱动程序 (ver 2.8.1) 是否支持此查询？

http://192.168.1.151:5000/v2/odata/users?$filter=contains(Name, 'Smith')&$top=1&$count=true

如果我使用精确或 eq 过滤器，它会起作用

http://192.168.1.151:5000/v2/odata/users?$filter=Name eq 'Smith Alan')&$top=1&$count=true

[10:30:17.208  ERR][0HLO4RQ58RQQ9:00000001] Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware: An unhandled exception has occurred while executing the request.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.InvalidOperationException: IIF((({document}{name} == null) OrElse False), null, Convert({document}{name}.Contains("Loi"), Nullable`1)) is not supported.
   at MongoDB.Driver.Linq.Translators.PredicateTranslator.GetFieldExpression(Expression expression)
   at MongoDB.Driver.Linq.Translators.PredicateTranslator.TranslateComparison(Expression variableExpression, ExpressionType operatorType, ConstantExpression constantExpression)
   at MongoDB.Driver.Linq.Translators.PredicateTranslator.Translate(Expression node)
   at MongoDB.Driver.Linq.Translators.PredicateTranslator.Translate(Expression node, IBsonSerializerRegistry serializerRegistry)
   at MongoDB.Driver.Linq.Translators.QueryableTranslator.TranslateWhere(WhereExpression node)
   at MongoDB.Driver.Linq.Translators.QueryableTranslator.TranslateOrderBy(OrderByExpression node)
   at MongoDB.Driver.Linq.Translators.QueryableTranslator.TranslateTake(TakeExpression node)
   at MongoDB.Driver.Linq.Translators.QueryableTranslator.TranslateTake(TakeExpression node)
   at MongoDB.Driver.Linq.Translators.QueryableTranslator.TranslatePipeline(PipelineExpression node)
   at MongoDB.Driver.Linq.Translators.QueryableTranslator.Translate(Expression node, IBsonSerializerRegistry serializerRegistry, ExpressionTranslationOptions translationOptions)
   at MongoDB.Driver.Linq.MongoQueryProviderImpl`1.Execute(Expression expression)
   at MongoDB.Driver.Linq.MongoQueryableImpl`2.GetEnumerator()
   at System.Collections.Generic.List`1.AddEnumerable(IEnumerable`1 enumerable)
   at Microsoft.AspNet.OData.Query.TruncatedCollection`1..ctor(IQueryable`1 source, Int32 pageSize)
   at Microsoft.AspNet.OData.Query.ODataQueryOptions.LimitResults[T](IQueryable`1 queryable, Int32 limit, Boolean& resultsLimited)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at Microsoft.AspNet.OData.Query.ODataQueryOptions.LimitResults(IQueryable queryable, Int32 limit, Boolean& resultsLimited)
   at Microsoft.AspNet.OData.Query.ODataQueryOptions.ApplyTo(IQueryable query, ODataQuerySettings querySettings)
   at Microsoft.AspNet.OData.EnableQueryAttribute.ExecuteQuery(Object responseValue, IQueryable singleResultCollection, IWebApiActionDescriptor actionDescriptor, Func`2 modelFunction, IWebApiRequestMessage request, Func`2 createQueryOptionFunction)

Answer 1

该问题的解决方法是将HandleNullPropagation 添加为false。

 [EnableQuery( HandleNullPropagation = HandleNullPropagationOption.False)]
 public IActionResult Get()
 {
      return Ok(_db.MyMongoDataCollection().AsQueryable());
 }