efcore.pg: Can't scaffold pre-10 PostgreSQL with v3.0.0-preview8 because of missing pg_sequence schema table

I have a problem with database reverse engineering using Postgresql 9.5 and Npgsql 3.0.0-preview8 on dotnercore 3.0.100-preview8-013656.

The scaffolding fails with the following error :

the relation « pg_sequence » does not exist

If I’m not mistaken, newer versions of Npgsql use Postgresql 10/11 compatibility by default. How can I generate my dbContext from the database using dotnet command line with PG9.5 compatibility ?

I already set services.AddDbContextPool<myContext>(options => options.UseNpgsql(Configuration["ConnectionStrings:DefaultConnection"], o => o.SetPostgresVersion(9,5))); in my Startup class.

Is there a command line argument to ensure compatibility ?

Here is the command line I use :

dotnet ef dbcontext -p Target.Project.Name -s Startup.Project.Name scaffold `
	"Host=hostname;Port=1525;Database=dbname;Username=user;Password=pass" `
	Npgsql.EntityFrameworkCore.PostgreSQL `
	--context-dir . `
	--schema data `
	--table othershema.table `
	-o Entities `
	-f `
	-d

It worked without issues when I was using dotnetcore 2.2, but I wanted to update my project to be able to test the scaffolding of views.

Here is the full stack trace from dotnet command

Npgsql.PostgresException (0x80004005): 42P01: la relation « pg_sequence » n'existe pas
   at Npgsql.NpgsqlConnector.<>c__DisplayClass160_0.<<DoReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Npgsql.NpgsqlConnector.<>c__DisplayClass160_0.<<DoReadMessage>g__ReadMessageLong|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Npgsql.NpgsqlDataReader.NextResult(Boolean async, Boolean isConsuming)
   at Npgsql.NpgsqlDataReader.NextResult()
   at Npgsql.NpgsqlCommand.ExecuteDbDataReader(CommandBehavior behavior, Boolean async, CancellationToken cancellationToken)
   at Npgsql.NpgsqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal.NpgsqlDatabaseModelFactory.GetColumns(NpgsqlConnection connection, IReadOnlyList`1 tables, String tableFilter, HashSet`1 enums, IDiagnosticsLogger`1 logger)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal.NpgsqlDatabaseModelFactory.GetTables(NpgsqlConnection connection, Func`3 tableFilter, HashSet`1 enums, IDiagnosticsLogger`1 logger)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal.NpgsqlDatabaseModelFactory.Create(DbConnection dbConnection, DatabaseModelFactoryOptions options)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Scaffolding.Internal.NpgsqlDatabaseModelFactory.Create(String connectionString, DatabaseModelFactoryOptions options)
   at Microsoft.EntityFrameworkCore.Scaffolding.Internal.ReverseEngineerScaffolder.ScaffoldModel(String connectionString, DatabaseModelFactoryOptions databaseOptions, ModelReverseEngineerOptions modelOptions, ModelCodeGenerationOptions codeOptions)
   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_0.<.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)
  Exception data:
    Severity: ERREUR
    SqlState: 42P01
    MessageText: la relation « pg_sequence » n'existe pas
    Position: 1456
    File: parse_relation.c
    Line: 1159
    Routine: parserOpenTable