使用 "HasConversion()" 或任何其他方法在 Fluent API (EF Core) 中将字符串转换为 HierarchyId？

Question

我使用的是带有EF核心代码优先方法的FileTables。我已经使用存储过程从字符串中的FileTable(名为"DocumentStore"(中获取Path_Locator(PK(，现在正试图将其插入存储该文件信息的另一个表中。我已经在一个表中手动添加了外键约束，该表使用代码优先迁移来引用FileTable。因此，我想将检索到的Path_Locator(作为字符串(添加到另一个表中。但这里的问题是，我检索了字符串中的值，但外键约束的类型是hierarchyid。

这就是我在DbContext类中添加的方式

builder.Entity<ArticleFiles>(entity => {
entity.Property(x => x.PathLocator).HasColumnType("hierarchyid");
});

以下是堆栈跟踪：

Microsoft.EntityFrameworkCore.Database.Command[20102]
Failed executing DbCommand (87ms) [Parameters=[@p0='?' (DbType = Int32), @p1='?' (Size = 450), @p2='?' (Size = 4000), @p3='?' (Size = 4000), @p4='?' (DbType = Int32), @p5='?' (Size = 450), @p6='?' (DbType
= Boolean)], CommandType='Text', CommandTimeout='30']
SET NOCOUNT ON;
INSERT INTO [ArticleFiles] ([ArticleId], [PathLocator], [FileDescription], [FileName], [FileTypeId], [GeneratedFileName], [IsAttachment])
VALUES (@p0, @p1, @p2, @p3, @p4, @p5, @p6);
fail: Microsoft.EntityFrameworkCore.Update[10000]
An exception occurred in the database while saving changes for context type 'PublicationFinal.Data.DataContext'.
Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details.
---> Microsoft.Data.SqlClient.SqlException (0x80131904): A .NET Framework error occurred during execution of user-defined routine or aggregate "hierarchyid":
Microsoft.SqlServer.Types.HierarchyIdException: 24001: SqlHierarchyId.Parse failed because the input string '0xFD92800AD195392FF75255D5F1E836FB6FD89006BFD8987C037B7061F86242EF9612661F45F8F1084C' is not a
valid string representation of a SqlHierarchyId node.
Microsoft.SqlServer.Types.HierarchyIdException:
at Microsoft.SqlServer.Types.SqlHierarchyId.Parse(SqlString input)
.
The statement has been terminated.
at Microsoft.Data.SqlClient.SqlCommand.<>c.<ExecuteDbDataReaderAsync>b__164_0(Task`1 result)
at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
ClientConnectionId:f2ef6681-7b4c-41bb-b313-b8c6acbfd34a
Error Number:6522,State:2,Class:16
--- End of inner exception stack trace ---
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(DbContext _, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellatio
nToken)
at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. See the inner exception for details.
---> Microsoft.Data.SqlClient.SqlException (0x80131904): A .NET Framework error occurred during execution of user-defined routine or aggregate "hierarchyid":
Microsoft.SqlServer.Types.HierarchyIdException: 24001: SqlHierarchyId.Parse failed because the input string '0xFD92800AD195392FF75255D5F1E836FB6FD89006BFD8987C037B7061F86242EF9612661F45F8F1084C' is not a valid
string representation of a SqlHierarchyId node.
Microsoft.SqlServer.Types.HierarchyIdException:
at Microsoft.SqlServer.Types.SqlHierarchyId.Parse(SqlString input)
.
The statement has been terminated.
at Microsoft.Data.SqlClient.SqlCommand.<>c.<ExecuteDbDataReaderAsync>b__164_0(Task`1 result)
at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location where exception was thrown ---
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
ClientConnectionId:f2ef6681-7b4c-41bb-b313-b8c6acbfd34a
Error Number:6522,State:2,Class:16
--- End of inner exception stack trace ---
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(DbContext _, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken
)
at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)

在将该字符串放入数据库之前，我可以使用fluentapi中的一些方法将其转换为HierarchyId吗？

Answer 1

我想您需要字符串函数，但尽量完全回答。

您可以将hierarchyid转换为新列或临时表中的字符串，然后使用它。

例如，如果您有以下表格：

CREATE TABLE SimpleDemo  
(
Level hierarchyid NOT NULL,  
Location nvarchar(30) NOT NULL,  
LocationType nvarchar(9) NULL
);
Go
INSERT SimpleDemo  
VALUES   
('/1/', 'Europe', 'Continent'),  
('/2/', 'South America', 'Continent'),  
('/1/1/', 'France', 'Country'),  
('/1/1/1/', 'Paris', 'City'),  
('/1/2/1/', 'Madrid', 'City'),  
('/1/2/', 'Spain', 'Country'),  
('/3/', 'Antarctica', 'Continent'),  
('/2/1/', 'Brazil', 'Country'),  
('/2/1/1/', 'Brasilia', 'City'),  
('/2/1/2/', 'Bahia', 'State'),  
('/2/1/2/1/', 'Salvador', 'City'),  
('/3/1/', 'McMurdo Station', 'City');
Go

你可以找到这样的结果：

SELECT CAST(Level AS nvarchar(100)) AS [Converted Level], *   
FROM SimpleDemo ORDER BY Level

您可以使用以下功能：

Select Level.ToString()
From SimpleDemo

我希望这个有用

如果你想使用c#函数来转换这个层次结构，你可以使用这个代码，但你应该安装SSDT，SQLCLIENT：

using System;  
using System.Collections;  
using System.Text;  
using Microsoft.SqlServer.Server;  // SqlFunction Attribute
using Microsoft.SqlServer.Types;   // SqlHierarchyId
public partial class HierarchyId_Operations  
{  
[SqlFunction(FillRowMethodName = "FillRow_ListAncestors")]
public static IEnumerable ListAncestors(SqlHierarchyId h)
{  
while (!h.IsNull)  
{  
yield return (h);  
h = h.GetAncestor(1);  
}  
}  
public static void FillRow_ListAncestors(
Object obj,
out SqlHierarchyId ancestor
)
{  
ancestor = (SqlHierarchyId)obj;  
}  
public static HierarchyId CommonAncestor(
SqlHierarchyId h1,
HierarchyId h2
)  
{  
while (!h1.IsDescendantOf(h2))  
h1 = h1.GetAncestor(1);  
return h1;  
}  
}

你可以在这里找到这个样品