Erro em Tratamento de exceção

Estou recebendo este erro de excessão ao tentar inserir as informações no banco:

Oracle.ManagedDataAccess.Client.OracleException occurred

HResult=0x80004005

Message=ORA-00923: palavra-chave FROM não localizada onde esperada

Source=Oracle Data Provider for .NET, Managed Driver

StackTrace:

at OracleInternal.ServiceObjects.OracleConnectionImpl.VerifyExecution(Int32& cursorId, Boolean bThrowArrayBindRelatedErrors, SqlStatementType sqlStatementType, Int32 arrayBindCount, OracleException& exceptionForArrayBindDML, Boolean& hasMoreRowsInDB, Boolean bFirstIterationDone)

at OracleInternal.ServiceObjects.OracleCommandImpl.ExecuteReader(String commandText, OracleParameterCollection paramColl, CommandType commandType, OracleConnectionImpl connectionImpl, OracleDataReaderImpl& rdrImpl, Int32 longFetchSize, Int64 clientInitialLOBFS, OracleDependencyImpl orclDependencyImpl, Int64[] scnForExecution, Int64[]& scnFromExecution, OracleParameterCollection& bindByPositionParamColl, Boolean& bBindParamPresent, Int64& internalInitialLOBFS, OracleException& exceptionForArrayBindDML, OracleConnection connection, OracleLogicalTransaction& oracleLogicalTransaction, IEnumerable`1 adrianParsedStmt, Boolean isDescribeOnly, Boolean isFromEF)

at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader(Boolean requery, Boolean fillRequest, CommandBehavior behavior)

at Oracle.ManagedDataAccess.Client.OracleCommand.ExecuteReader()

at ImportComprovante.DB.ExecutaComandoComRetorno(String strQuery) in C:\Users\robson.amaral\source\repos\ImportComprovante\ImportComprovante\ImportComprovante\DB.cs:line 39

at ImportComprovante.LeituraTxt.CodBarraJaInserido(String CodBarra) in C:\Users\robson.amaral\source\repos\ImportComprovante\ImportComprovante\ImportComprovante\LeituraTxt.cs:line 234

at ImportComprovante.LeituraTxt.ProcessaArquivo(String FullPathFile, String FileName) in C:\Users\robson.amaral\source\repos\ImportComprovante\ImportComprovante\ImportComprovante\LeituraTxt.cs:line 193

at ImportComprovante.LeituraTxt.VerificarHorario() in C:\Users\robson.amaral\source\repos\ImportComprovante\ImportComprovante\ImportComprovante\LeituraTxt.cs:line 52

at System.Threading.ThreadHelper.ThreadStart_Context(Object state)

at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)

at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)

at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)

at System.Threading.ThreadHelper.ThreadStart()

Meus códigos:

public OracleDataReader ExecutaComandoComRetorno(string strQuery)
{

 var cmdComando = new OracleCommand
 {
 CommandText = strQuery,
 CommandType = System.Data.CommandType.Text,
 Connection = conexao
 };

 return cmdComando.ExecuteReader(); //Linha 39
 }

private static bool CodBarraJaInserido(string CodBarra)
{

 using (DB db = new DB())
 {
 string SQL = string.Format(@"SELECT count(T0.cod_barras_banestes) 'Existe'
 FROM sdpj_comprovante_banestes T0 WHERE T0.cod_barras_banestes = '{0}'", CodBarra);
 var dados = db.ExecutaComandoComRetorno(SQL); //Linha 234
 }
 }

catch (Exception)
{
throw; //Linha 193
}

try
{

 DirectoryInfo dirPendentes = new DirectoryInfo(PastaArquivosPendentes);

 // lista arquivos do diretorio corrente
 foreach (FileInfo file in dirPendentes.GetFiles())
 {
 if(file.Extension == ".cpv")
 {
 ProcessaArquivo(file.FullName, file.Name);
 }
 }

 }
 catch (Exception)
 {
 throw; //Linha 52
 }
 finally
 {
 InsertLog("\n FIM :: " + DateTime.Now.ToShortDateString() + " " + DateTime.Now.ToShortTimeString());
 }