CtreeSqlCommand.CommandType property indicates how the FairCom DB SQL database command is to be interpreted. CommandType.Text and CommandType.StoredProcedure are supported. By default, CtreeSqlCommand.CommandType is set to CommandType.Text. If you try to set the CommandType property of CtreeSqlCommand object with any other value, an UnsupportedException is thrown. The other possible value for CommandType is TableDirect. (According to Microsoft documentation, TableDirect is only supported by an OleDB .NET data provider.)