.NET Core 3.1 和 SQL 服务器hierarchyid - 多个异常

Question

I work with SQL Server Db in my.Net Core 3.1 project and some stored procedures and views have hierarchyid types for parameters and data.

I use Microsoft.Data.SqlClient package. And when I try to read data with SqlDataReader I get the exception:

System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.SqlServer.Types, Version=10.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91'. The system cannot find the file specified.

ok, I tried to use Microsoft.SqlServer.Types as it suggests but this package is not .NET Standard and it doesn't work.

Also, I found EntityFrameworkCore.SqlServer.HierarchyId but when I use it I get:

System.InvalidCastException: Unable to cast object of type 'Microsoft.SqlServer.Types.SqlHierarchyId' to type 'Microsoft.Data.SqlClient.Server.IBinarySerialize'.

So how on Earth can one use HierarchyId type in .NET Core 3.1?

I'm planning to host this solution on linux.

UPDATE

I do use Microsoft.Data.SqlClient 2.0 which is compatible with .NET Core. Also, I added then EntityFrameworkCore.SqlServer.HierarchyId , and I get this error:

System.InvalidCastException: Unable to cast object of type 'Microsoft.SqlServer.Types.SqlHierarchyId' to type 'Microsoft.Data.SqlClient.Server.IBinarySerialize'.

Here's the.csproj:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="EntityFrameworkCore.SqlServer.HierarchyId" Version="1.1.0" />
    <PackageReference Include="Microsoft.Data.SqlClient" Version="2.0.0" />
    <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
  </ItemGroup>

  <ItemGroup>
    <Folder Include="Helpers\" />
  </ItemGroup>

</Project>

No luck so far.

UPDATE 2

This is the code where the exception is thrown:

using (SqlDataReader reader = await detailsCmd.ExecuteReaderAsync())
{
  while (reader.Read())
  {
    details.Add(new HierarchyDetails
    {
      Id = reader.GetInt32(0),
      groupPath = reader.GetValue(1).ToString(), // <==== EXCEPTION
      name = reader.GetString(2),
      optionalData = reader.IsDBNull(3) ? null : reader.GetString(3)
    });
  }
}

And the table has the only row:

id  groupPath   culture name    optionalData
24  0x58        en-US   testing 

Answer 1

Your error message suggests that you use something which uses nuget https://www.nuget.org/packages/Microsoft.SqlServer.Types/10.50.1600.1 which is .NET Framework dll, not .NET Core.

You mention that you use Microsoft.Data.SqlClient , please ensure that you use https://www.nuget.org/packages/Microsoft.Data.SqlClient/ which is compatible with .NET Core.

In case of other errors please check also Entity Framework Core hierarchyid

Answer 2

The solution at the moment to cast hierarchyid to NVARCHAR in all your queries:

... CAST(groupPath as NVARCHAR(4000)) as groupPath ...

and then use it as string.