Devart Forums

Hi,

I am using Devart dotConnect for Oracle version 9.11.980 with Entity Framework 6.4.4 version in .Net Framework 4.7.2. The connection is done to an Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production, from a machine where we have Oracle Client version 12.2.0.1.0, where both 32 bit and 64 bit are installed. In Environment variable Path, 32 bit path is before the 64bit path.

Sometimes the following error is encountered when saving a record which has a column with XMLTYPE type:

System.AccessViolationException
at OciDynamicType.nativeOCILobWrite(System.Runtime.InteropServices.HandleRef, System.Runtime.InteropServices.HandleRef, IntPtr, Int32 ByRef, Int32, Byte[], Int32, Byte, Int32, Int32, Int16, Byte)
at OciDynamicType.OCILobWrite(System.Runtime.InteropServices.HandleRef, System.Runtime.InteropServices.HandleRef, IntPtr, Int32 ByRef, Int32, Byte[], Int32, Byte, Int32, Int32, Int16, Byte)
at Devart.Data.Oracle.ch.a(Int32, Byte[], Int32, Int32)
at Devart.Data.Oracle.bu.a(Int32, Byte[], Int32, Int32)
at Devart.Data.Oracle.t.a(System.String)
at Devart.Data.Oracle.t..ctor(System.String, Devart.Data.Oracle.dm)
at Devart.Data.Oracle.bv.a(Devart.Data.Oracle.b0, System.String)
at Devart.Data.Oracle.OracleXml.b()
at Devart.Data.Oracle.OracleParameter.a(Devart.Data.Oracle.OracleDbType, System.Object, System.Object, Byte[], System.Collections.Hashtable, Int32, Int32, Int32, Int32, Int32, Boolean, Devart.Data.Oracle.OracleConnection, System.Data.ParameterDirection, Devart.Data.Oracle.OracleType, Devart.Data.Oracle.b0, Boolean ByRef)
at Devart.Data.Oracle.OracleParameter.a(Devart.Data.Oracle.b4 ByRef, Boolean, Devart.Data.Oracle.OracleConnection, Byte[], System.Collections.Hashtable, Devart.Data.Oracle.b0, Boolean ByRef, Int32) at Devart.Data.Oracle.OracleCommand.a(Devart.Data.Oracle.cr, Int32, Devart.Data.Oracle.OracleParameterCollection, Devart.Data.Oracle.b0, Boolean ByRef) at Devart.Data.Oracle.OracleCommand.InternalExecute(System.Data.CommandBehavior, System.IDisposable, Int32, Int32, Boolean)
at Devart.Common.DbCommandBase.ExecuteDbDataReader(System.Data.CommandBehavior, Boolean)
at Devart.Data.Oracle.OracleCommand.ExecuteNonQuery()
at Devart.Data.Oracle.Entity.ag.h()
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher+<>c.<NonQuery>b__4_0(System.Data.Common.DbCommand, System.Data.Entity.Infrastructure.Interception.DbCommandInterceptionContext`1<Int32>)
at System.Data.Entity.Infrastructure.Interception.InternalDispatcher`1[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]].Dispatch[[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.__Canon, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089],[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]](System.__Canon, System.Func`3<System.__Canon,System.__Canon,Int32>, System.__Canon, System.Action`3<System.__Canon,System.__Canon,System.__Canon>, System.Action`3<System.__Canon,System.__Canon,System.__Canon>)
at System.Data.Entity.Infrastructure.Interception.DbCommandDispatcher.NonQuery(System.Data.Common.DbCommand, System.Data.Entity.Infrastructure.Interception.DbCommandInterceptionContext)
at System.Data.Entity.Internal.InterceptableDbCommand.ExecuteNonQuery()
at System.Data.Entity.Core.Mapping.Update.Internal.DynamicUpdateCommand.Execute(System.Collections.Generic.Dictionary`2<Int32,System.Object>, System.Collections.Generic.List`1<System.Collections.Generic.KeyValuePair`2<System.Data.Entity.Core.Mapping.Update.Internal.PropagatorResult,System.Object>>)
at System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator.Update()
at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter+<>c.<Update>b__21_0(System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator)
at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]](Int32, System.Func`2<System.Data.Entity.Core.Mapping.Update.Internal.UpdateTranslator,Int32>)
at System.Data.Entity.Core.EntityClient.Internal.EntityAdapter.Update()
at System.Data.Entity.Core.Objects.ObjectContext.<SaveChangesToStore>b__153_0()
at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]](System.Func`1<Int32>, System.Data.Entity.Infrastructure.IDbExecutionStrategy, Boolean, Boolean)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesToStore(System.Data.Entity.Core.Objects.SaveOptions, System.Data.Entity.Infrastructure.IDbExecutionStrategy, Boolean)
at System.Data.Entity.Core.Objects.ObjectContext+<>c__DisplayClass148_0.<SaveChangesInternal>b__0()
at System.Data.Entity.Infrastructure.DefaultExecutionStrategy.Execute[[System.Int32, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]](System.Func`1<Int32>)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChangesInternal(System.Data.Entity.Core.Objects.SaveOptions, Boolean)
at System.Data.Entity.Core.Objects.ObjectContext.SaveChanges(System.Data.Entity.Core.Objects.SaveOptions)
at System.Data.Entity.Internal.InternalContext.SaveChanges()
at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
at System.Data.Entity.DbContext.SaveChanges() .

This exception happens in a windows service, where we consume messages from a service bus and where the Entity Framework DbContext lifetime is scoped to the message consumer lifetime. Sometimes, this exception happens when there is a continuous load activity on the database, sometimes when there is a single activity on the database.

Can you please give me directions in finding the cause of this exception?

Thank you!

We will investigate the issue and notify you about the result.

The bug with throwing AccessViolationException by OracleCommand.ExecuteScalar() in the OCI mode is fixed in dotConnect for Oracle v9.14.1228: https://forums.devart.com/viewtopic.php?f=1&t=44776.

If this fix doesn't help with the issue you have encountered, please localize the problem in a small test project and send it to us with the corresponding DDL/DML script.