private sealed class MyContext:TestBaseDbContext
 {
  [Table("TEST_MODIFY_ROW_WD")]
  public class TEST_MODIFY_ROW_WD
  {
   [Key]
   [Column("TEST_ID")]
   public Int64 TEST_ID { get; set; }

   [Column(TypeName="BLOB SUB_TYPE TEXT")]
   public string COL_TEXT_BLOB { get; set; }
  };//class TEST_MODIFY_ROW_WD

  //----------------------------------------------------------------------
  public DbSet<TEST_MODIFY_ROW_WD> testTable { get; set; }

  //----------------------------------------------------------------------
  public MyContext(xdb.OleDbTransaction tr)
   :base(tr)
  {
  }//MyContext
 };//class MyContext

 [Test]
 public static void Test_02()
 {
  var v_testStr=new string('Z',16*1024*1024); //16MB

  using(var cn=new xdb.OleDbConnection(TestServices.Conf__GetCnStr()))
  {
   cn.Open();

   using(var tr=cn.BeginTransaction())
   {
    object recID;

    using(var db=new MyContext(tr))
    {
     {
      var newRecord=new MyContext.TEST_MODIFY_ROW_WD();

      newRecord.COL_TEXT_BLOB=v_testStr;

      db.testTable.Add(newRecord);

      db.SaveChanges();

      recID=newRecord.TEST_ID;
     }//local

     int nRecs=0;

     foreach(var rec in db.testTable.Where(r=>r.TEST_ID==(Int64)recID))
     {
      Assert.AreEqual(0,nRecs);

      ++nRecs;

      Assert.AreEqual(recID,rec.TEST_ID);

      Assert.AreEqual(v_testStr,rec.COL_TEXT_BLOB);
     }//foreach rec

     Assert.AreEqual(1,nRecs);
    }//using db

    tr.Rollback();
   }//using tr
  }//using cn
 }//Test_02

Имя теста:	Test_02
Полное имя теста:	ef_core__lcpi_oledb__ntests.Work.DataTypes.Group001.Work_DataTypes_Group001__Test_011__BLOB_TEXT.Test_02
Источник теста:	d:\Users\Dima\Work2\TestCode\users\Dima\TestCode\EFCore_LcpiOleDb_v1\ntest\Source\Work\DataTypes\Group001\Work_DataTypes_Group001__Test_011__BLOB_TEXT.cs : строка 95
Результаты теста:	Пройден
Длительность теста:	0:00:03,517

Стандартный вывод результата:	
LOG [1]: An additional 'IServiceProvider' was created for internal use by Entity Framework. An existing service provider was not used due to the following configuration changes: configuration added for 'LcpiOleDb', configuration added for 'Core:UseMemoryCache', configuration added for 'Core:EnableSensitiveDataLogging', configuration added for 'Core:EnableDetailedErrors', configuration added for 'Core:ConfigureWarnings'.
LOG [1]: Entity Framework Core 3.0.0-dev initialized 'MyContext' using provider 'EntityFrameworkCore.DataProvider.Lcpi.OleDb.nets2_0.debug' with options: None
LOG [1]: Using an existing transaction with isolation level 'ReadCommitted'.
LOG [1]: 'MyContext' generated a temporary value for the 'TEST_ID' property of new 'TEST_MODIFY_ROW_WD' entity. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
LOG [1]: Context 'MyContext' started tracking 'TEST_MODIFY_ROW_WD' entity. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
LOG [1]: SaveChanges starting for 'MyContext'.
LOG [1]: DetectChanges starting for 'MyContext'.
LOG [1]: DetectChanges completed for 'MyContext'.
LOG [1]: Executing DbCommand [Parameters=[p0='?' (Size = 2147483647), p1='?' (Size = 8) (Precision = 19) (Direction = Output) (DbType = Int64)], CommandType='Text', CommandTimeout='30']
INSERT INTO "TEST_MODIFY_ROW_WD" ("COL_TEXT_BLOB")
VALUES (:p0)
RETURNING "TEST_ID"
INTO :p1;
LOG [1]: Executed DbCommand (359ms) [Parameters=[p0='?' (Size = 2147483647), p1='?' (Size = 8) (Precision = 19) (Direction = Output) (DbType = Int64)], CommandType='Text', CommandTimeout='30']
INSERT INTO "TEST_MODIFY_ROW_WD" ("COL_TEXT_BLOB")
VALUES (:p0)
RETURNING "TEST_ID"
INTO :p1;
LOG [1]: Foreign key property 'TEST_MODIFY_ROW_WD.TEST_ID' detected as changed. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see property values.
LOG [1]: A data reader was disposed.
LOG [1]: An 'TEST_MODIFY_ROW_WD' entity tracked by 'MyContext' changed from 'Added' to 'Unchanged'. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see key values.
LOG [1]: SaveChanges completed for 'MyContext' with 1 entities written to the database.
LOG [1]: Compiling query model: 
'from TEST_MODIFY_ROW_WD r in DbSet<TEST_MODIFY_ROW_WD>
where [r].TEST_ID == __recID_0
select [r]'
LOG [1]: Optimized query model: 
'from TEST_MODIFY_ROW_WD r in DbSet<TEST_MODIFY_ROW_WD>
where [r].TEST_ID == __recID_0
select [r]'
LOG [1]: (QueryContext queryContext) => IEnumerable<TEST_MODIFY_ROW_WD> _InterceptExceptions(
|__ source: IEnumerable<TEST_MODIFY_ROW_WD> _TrackEntities(
|   |__ results: IEnumerable<TEST_MODIFY_ROW_WD> _ShapedQuery(
|   |   |__ queryContext: queryContext, 
|   |   |__ shaperCommandContext: SelectExpression: 
|   |   |       SELECT "r"."TEST_ID", "r"."COL_TEXT_BLOB"
|   |   |       FROM "TEST_MODIFY_ROW_WD" AS "r"
|   |   |       WHERE "r"."TEST_ID" = :__recID_0, 
|   |   |__ shaper: (MaterializationContext materializationContext) => 
|   |       {
|   |           instance = new TEST_MODIFY_ROW_WD()
|   |           instance.<TEST_ID>k__BackingField = long TryReadValue(ValueBuffer materializationContext.get_ValueBuffer(), 0)
|   |           instance.<COL_TEXT_BLOB>k__BackingField = string TryReadValue(ValueBuffer materializationContext.get_ValueBuffer(), 1)
|   |           return instance
|   |       }), 
|   |__ queryContext: queryContext, 
|   |__ entityTrackingInfos: { itemType: TEST_MODIFY_ROW_WD }, 
|   |__ entityAccessors: List<Func<TEST_MODIFY_ROW_WD, object>> 
|       { 
|           Func<TEST_MODIFY_ROW_WD, TEST_MODIFY_ROW_WD>, 
|       }), 
|__ contextType: ef_core__lcpi_oledb__ntests.Work.DataTypes.Group001.Work_DataTypes_Group001__Test_011__BLOB_TEXT+MyContext, 
|__ logger: DiagnosticsLogger<Query>, 
|__ queryContext: queryContext)
LOG [1]: Executing DbCommand [Parameters=[__recid_0='?' (Size = 8) (Precision = 19) (DbType = Int64)], CommandType='Text', CommandTimeout='30']
SELECT "r"."TEST_ID", "r"."COL_TEXT_BLOB"
FROM "TEST_MODIFY_ROW_WD" AS "r"
WHERE "r"."TEST_ID" = :__recID_0
LOG [1]: Executed DbCommand (13ms) [Parameters=[__recid_0='?' (Size = 8) (Precision = 19) (DbType = Int64)], CommandType='Text', CommandTimeout='30']
SELECT "r"."TEST_ID", "r"."COL_TEXT_BLOB"
FROM "TEST_MODIFY_ROW_WD" AS "r"
WHERE "r"."TEST_ID" = :__recID_0
LOG [1]: A data reader was disposed.
LOG [1]: 'MyContext' disposed.