Question

我编写了以下代码，通过表单将数据插入到数据库中，但是在加载页面时会自动将空值插入到数据库中，请帮助我。如果可能的话，请使用spring mvc，mysql和jsp为我提供一个简单的例子。

<%@include file="header.jsp" %>
<!-- topbar ends -->
<div class="ch-container">
<div class="row">    
    <!-- left menu starts -->
    <div class="col-sm-2 col-lg-2">
        <div class="sidebar-nav">
            <div class="nav-canvas">
                <div class="nav-sm nav nav-stacked">

                </div>
                <ul class="nav nav-pills nav-stacked main-menu">
                    <li class="nav-header">Main</li>
                    <li><a class="ajax-link" href="deshboard.jsp"><i class="glyphicon glyphicon-home"></i><span> Home</span></a></li>
                    <li><a class="ajax-link" href="view_emp_list.jsp"><i class="glyphicon glyphicon-eye-open"></i><span> Employee List</span></a></li>
                </ul>
                <label id="for-is-ajax" for="is-ajax"><input id="is-ajax" type="checkbox"> Ajax on menu</label>
            </div>
        </div>
    </div>
    <!--/span-->
    <!-- left menu ends -->
    <noscript>
        <div class="alert alert-block col-md-12">
            <h4 class="alert-heading">Warning!</h4>

            <p>You need to have <a href="http://en.wikipedia.org/wiki/JavaScript" target="_blank">JavaScript</a>
                enabled to use this site.</p>
        </div>
    </noscript>
    <div id="content" class="col-lg-10 col-sm-10">
        <!-- content starts -->
        <div>
            <ul class="breadcrumb">
                <li>
                    <a href="#">Home</a>
                </li>
                <li>
                    <a href="#">Blank</a>
                </li>
            </ul>
        </div>
        <div class="row">
            <div class="box col-md-12">
                <div class="box-inner">
                    <div class="box-header well" data-original-title="">
                        <h2><i class="glyphicon glyphicon-edit"></i> Recruitment</h2>

                        <div class="box-icon">
                            <a href="#" class="btn btn-setting btn-round btn-default"><i
                                    class="glyphicon glyphicon-cog"></i></a>
                            <a href="#" class="btn btn-minimize btn-round btn-default"><i
                                    class="glyphicon glyphicon-chevron-up"></i></a>
                            <a href="#" class="btn btn-close btn-round btn-default"><i
                                    class="glyphicon glyphicon-remove"></i>    </a>
                        </div>
                    </div>
                    <div class="box-content">
                        <form method="POST" action="<%
String emp_idno=request.getParameter("emp_idno");
session.setAttribute( "theEmp_Id_No", emp_idno ); 
String emp_cid=request.getParameter("emp_cid");
String emp_fname=request.getParameter("emp_fname");
String emp_mname=request.getParameter("emp_mname");
String emp_lname=request.getParameter("emp_lname");

String sql="insert into tblemployee(fldEmployment_No,fldCitizenship_Id_No,fldFirst_Name,fldMiddle_Name,fldLast_Name) "
        + "values('"+emp_idno+"','"+emp_cid+"','"+emp_fname+"','"+emp_mname+"','"+emp_lname+"')";

try{
    int action=conn.createStatement().executeUpdate(sql);
    conn.setAutoCommit(true);
    if (action >= 1){          
        String site = new String("view_emp.htm");
        response.setStatus(response.SC_MOVED_TEMPORARILY);
        response.setHeader("Location", site);
    }else{
      //  out.println("Not saved");
    }
}catch(Exception e){
    e.printStackTrace();
}
%>" >

                            <div class="form-group col-md-6">
                                <label class="control-label" for="inputSuccess4">Employment Id</label>
                                <input name="emp_idno" type="text" class="form-control" id="inputSuccess4">
                            </div>
                            <div class="form-group col-md-6">
                                <label class="control-label" for="inputSuccess4">Citizenship ID Card No or Passport No</label>
                                <input name="emp_cid" type="text" class="form-control" id="inputSuccess4">
                            </div>
                            <div class="form-group col-md-4">
                                <label class="control-label" for="inputSuccess1">* First Name</label>
                                <input name="emp_fname" type="text" class="form-control" id="inputSuccess1">
                            </div>
                            <div class="form-group col-md-4">
                                <label class="control-label" for="inputWarning1">Middle Name</label>
                                <input name="emp_mname" type="text" class="form-control" id="inputWarning1">
                            </div>
                            <div class="form-group col-md-4">
                                <label class="control-label" for="inputError1">* Last Name</label>
                                <input name="emp_lname" type="text" class="form-control" id="inputError1">
                            </div>
                            <div class="form-group col-md-12">
                                <label for="control-label">Photograph</label>
                                <input type="file" id="exampleInputFile">
                                <p class="help-block">Accepts .jpg, .png, .gif up to 1MB. Recommended dimensions: 200px X 200px</p>
                            </div>
                            <div class="form-group">
                            <button type="submit" class="btn btn-default">Submit</button>
                            <button type="reset" class="btn btn-default">Cancel</button>    
                            </div>
                        </form>
                    </div>
                </div>
            </div>
            <!--/span-->
        </div><!--/row-->
        <!-- content ends -->
    </div><!--/#content.col-md-0-->
</div><!--/fluid-row-->
<hr>
<div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel"
     aria-hidden="true">

    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal">×</button>
                <h3>Settings</h3>
            </div>
            <div class="modal-body">
                <p>Here settings can be configured...</p>
            </div>
            <div class="modal-footer">
                <a href="#" class="btn btn-default" data-dismiss="modal">Close</a>
                <a href="#" class="btn btn-primary" data-dismiss="modal">Save changes</a>
            </div>
        </div>
    </div>
</div>
<%@include file="footer.jsp" %>

Answer 1

它将进行插入，因为在加载此jsp页面时会发生数据插入。

创建一个单独的jsp来保存表单输入组件，并使其表单操作为您为数据插入提供逻辑的jsp，或者使用servlet进行数据插入。

还要考虑在请求参数上添加非空验证

在不提交表单的情况下将空数据插入数据库

1 个答案: