ODP.NET Core - Scaffold DB-Context

问题

I am working with oracles odp.net core beta 3. Specifically, The dll is Oracle.ManagedDataAccess.Core.2.12.0-beta3. The project is to create a web api that sits on top of an oracle instance.

My question - Is the command "Scaffold-DBContext" supported with this provider. If so what am I doing wrong... I've made the attempt using a connection string similar to the following.

Data Source={databasename}/{TNS}.domain.local; User ID={UserName};Password={Password};

And the actual command in the Package Manager terminal

Scaffold-DbContext Data Source={databasename}/{TNS}.domain.local; User ID={UserName};Password={Password};" Oracle.ManagedDataAccess -OutputDir Models -Tables {TableName}

I get the following error which sugests it cannot fond a DesignTimeServiceAttribute in the provider assembly.

I also have Microsoft.EntityFrameworkCore.Tools (2.2.0) referenced which includes the design tools.

ERROR

    System.InvalidOperationException: Unable to find expected assembly attribute named DesignTimeProviderServicesAttribute in provider assembly Oracle.ManagedDataAccess. This attribute is required to identify the class which acts as the design-time service provider factory.
   at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.ConfigureProviderServices(String provider, IServiceCollection services, Boolean throwOnError)
   at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.Build(String provider)
   at Microsoft.EntityFrameworkCore.Design.Internal.DatabaseOperations.ScaffoldContext(String provider, String connectionString, String outputDir, String outputContextDir, String dbContextClassName, IEnumerable`1 schemas, IEnumerable`1 tables, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContextImpl(String provider, String connectionString, String outputDir, String outputDbContextDir, String dbContextClassName, IEnumerable`1 schemaFilters, IEnumerable`1 tableFilters, Boolean useDataAnnotations, Boolean overwriteFiles, Boolean useDatabaseNames)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.ScaffoldContext.<>c__DisplayClass0_1.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.<Execute>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

回答1:

I experienced the problems that you experienced, even after downloading the ODP.NET Core driver for production (2.18.3, released on 20-Sept-2018 and available from nuget at https://www.nuget.org/packages/Oracle.ManagedDataAccess.Core/).

I contacted the Oracle community for help. A kind soul answered that there's another piece of the puzzle if we want to have a ready access to goodness such as "UseOracle." It is the Oracle provider for the Entity Framework Core. See the thread at https://community.oracle.com/thread/4180739.

The only other way to use it, to my knowledge and based on his answer, is the way described in the Oracle Help Center, Getting Started with ODP.NET Core (https://www.oracle.com/webfolder/technetwork/tutorials/obe/db/dotnet/ODPNET_Core_get_started/index.html).

回答2:

I managed to scaffold it using

scaffold-dbcontext "Data Source=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=1.1.1.1)(PORT=1521))(CONNECT_DATA=(SERVICE_NAME=MYdb)));Persist Security Info=True;User Id=MYUSER;Password=mypass;" Oracle.EntityFrameworkCore

But it's an unusable mess. tons of errors

Could not scaffold the foreign key 'XX.TABLE1(USER_ID,USER_ID)'. A key for 'ID,ID' was not found in the principal entity type 'Aspnetusers'.

Seems like Dapper is my friend...

来源：https://stackoverflow.com/questions/52280091/odp-net-core-scaffold-db-context

标签

asp.net-core

odp.net