NVL的应用（只适合小测试，正式工程不能用）

insert into question values((select nvl(max(q_id),0)+1 from question),"name")

以下是徐培贡献给我的源代码：
真的很感谢他！！！
package manager;

import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionForm;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.Action;

public class m_interAction extends Action {
    public ActionForward execute(ActionMapping mapping, ActionForm form,
                                HttpServletRequest request,
                                HttpServletResponse response) {
        m_interActionForm m_interActionForm = (m_interActionForm) form;
        String type=m_interActionForm.getType();
        String question=m_interActionForm.getQuestion();
        String option=m_interActionForm.getOption();
        String kind=m_interActionForm.getKind();
        try{
            type=Tools.isoGb(type);
            question=Tools.isoGb(question);
            option=Tools.isoGb(option);
            kind=Tools.isoGb(kind);
        }catch(Exception e)
        {
            System.out.println("编码转换异常");
        }
        String sql = "insert into question values((select nvl(max(q_id),0)+1 from question),'" +
                    type + "','" + question + "','" + option + "','" + kind +"')";
        DB db = new DB();
        System.out.println("this is sql +++"+sql);
      boolean bl=db.update(sql);
      if(bl)
          return mapping.findForward("m_inter_success");
      else
          return mapping.findForward("m_inter_error");
    }
}