[英]System.NotSupportedException : 'The format of the given path is not supported.' C#
[英]Getting a NotSupportedException: Specified method is not supported. NHibernate C#
我有以下LINQ查询:
var coverageQuery = _repository.LogicalEcus
.Where(ecu => ecu.Alias != null)
.Select(ecu => ecu.Alias)
.Where(ecuAlias => searchTerm == "" || ecuAlias.Mnemonic.Contains(searchTerm.ToUpper()))
.OrderBy(ecuAlias => ecuAlias.Mnemonic)
.Select(x => x.Mnemonic)
.Distinct()
.Select(mnemonic => new Select2Result(mnemonic));
查询成功执行,但是将结果传递给Select2PagedResult构造函数时:
var result = new Select2PagedResult(coverageQuery, pageNum, pageSize);
它将失败,并显示以下错误:
[NotSupportedException:不支持指定的方法。] NHibernate.Hql.Ast.ANTLR.PolymorphicQuerySourceDetector.GetClassName(IASTNode querySource)+117 NHibernate.Hql.Ast.ANTLR.PolymorphicQuerySourceDetector.Process(IASTNode树)+188 NHibernate.Hql.Ast。 ANTLR.AstPolymorphicProcessor.Process()+51 NHibernate.Hql.Ast.ANTLR.ASTQueryTranslatorFactory.CreateQueryTranslators(IASTNode ast,字符串queryIdentifier,字符串collectionRole,布尔值浅,IDictionary 2 filters, ISessionFactoryImplementor factory) +154 NHibernate.Engine.Query.QueryPlanCache.GetHQLQueryPlan(IQueryExpression queryExpression, Boolean shallow, IDictionary
2 enabledFilters)+396 NHibernate.Impl.AbstractSessionImpl.GetHQLQueryPlan(IQueryExpression queryExpression,布尔浅)+149 NHibernate.Impl.AbstractSessionImpl.CreateQuery(IQueryExpression queryExpression)+133 NHibernate.Providerin (表达式,IQuery&查询,NhLinqExpression&nhQuery)+119 NHibernate.Linq.DefaultQu eryProvider.Execute(表达式表达式)+38 NHibernate.Linq.DefaultQueryProvider.Execute(表达式表达式)+15 Continental.INDiuM.WebUi.Models.Select2PagedResult..ctor(IQueryable`1列表,Int32 pageNumber,Int32 itemsPerPage)在C:\\ Projects \\ INDiuM \\ WebUi \\ Models \\ Select2PagedResult.cs:11 Continental.INDiuM.WebUi.Controllers.CoverageManagementController.GetCoverageAliases(String id,String searchTerm,Int32 pageSize,Int32 pageNum)在C:\\ Projects \\ INDiuM \\ WebUi \\ Controllers \\ CoverageManagementController .cs:124 lambda_method(Closure,ControllerBase,Object [])+301
Select2PagedResult的构造函数如下所示:
public Select2PagedResult(IQueryable<Select2Result> list, int pageNumber, int itemsPerPage)
{
Total = list.Count();
Results = list
.Skip((pageNumber - 1) * itemsPerPage)
.Take(itemsPerPage)
.ToList();
}
并且它将在Select2PagedResult的构造函数内部的这一行完全失败:
从上面的LINQ查询中删除.Distinct()可以解决问题,不会再次引发异常。
另外,如果我将Select2PagedResult的构造函数更改为接受List而不是IQueryable也可以工作:
public Select2PagedResult(List<Select2Result> list, int pageNumber, int itemsPerPage)
我也尝试重新排列LINQ查询顺序,但没有成功。
就像.Count()在NhQueryable上不存在。
我没有找到对此的解释,我真的不明白这是什么问题,尤其是因为它在几个月前就开始工作了……
任何建议,将不胜感激。
如果将AsEnumerable()
添加到查询的每个阶段,然后重试,则可以缩小焦点:
var coverageQuery =
_repository.LogicalEcus
.Where(ecu => ecu.Alias != null)
.Select(ecu => ecu.Alias)
.Where(ecuAlias => searchTerm == "" || ecuAlias.Mnemonic.Contains(searchTerm.ToUpper()))
.OrderBy(ecuAlias => ecuAlias.Mnemonic)
.Select(x => x.Mnemonic)
// Materialises and runs query. Rest is processed against objects.
// Any method that runs after this line but not before can be
// transformed into SQL equivalent
.AsEnumerable()
.Distinct()
.Select(mnemonic => new Select2Result(mnemonic));
您可以在列表中上下移动对AsEnumerable
的呼叫以找到罪魁祸首。
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