错误：‘bOS::SQL::SQLCommand::SQLOperation’既不是类也不是命名空间

/opt/cBPM/criteria-lin/src/Criteria/Criteria.WorkflowEngine/DataBase/DataBaseTemplate.cpp:1341:66: 错误：‘bOS::SQL::SQLCommand::SQLOperation’既不是类也不是命名空间

this->executeSQLCommands (connection, &vActivities,
SQLCommand::SQLOperation::SELECT, NULL, false);

namespace bOS
{
namespace SQL
{
class BOS_API SQLCommand
{
public:
SQLCommand();
virtual ~SQLCommand();

enum SQLOperation
{
ADD,
MODIFY,
ERASE,
SELECT,
CREATE,
DROP
};

解决办法：

SQLCommand::SQLOperation::SELECT

替换为：

SQLCommand::SELECT

Getting an “enum is not a class or namespace” error - C++ [duplicate]