在jsp jstl中，等于和不等于opertions不起作用 [英] Equal and not equal opertions are not working in jsp jstl

问题描述

 <   sql：query     datasource   =  $ {dbsource}    var   =  result2    xmlns：sql   = ＃unknown >  
来自用户的SELECT *; 
 <   / sql：query  >  
 
 <   c：out     value   =  $ {param.name}    xmlns：c   = ＃unknown    /  >  
 <   br  >  
 
 
 <  < span class =code-leadattribute> c：foreach     var   =  row   项目  =  $ {result2.rows}    xmlns：c   = ＃unknown >  
 <   c：out    值  =  $ {param.user_name}    /  >   <   br  >  
 
 <   c：选择 >  
 
 <   c：何时    test   =  $ {param.name eq row .user_name} >  
 <   font     size   =   5    color  < span class =code-keyword> =  red > 用户名已存在。请选择不同的名称<   / font  >  <   br  >  
 <   a     href   =  NewUser.jsp > 输入其他用户名< ;   / a  >  
 <   / br  >  < ;   / c：当 >  
 
 
 <   c：何时    test   =  $ {param.name ne param.user_name} >  
 < ;   sql：update     datasource   =  $ {dbsource}    var   =  result    xmlns：sql   = ＃unknown >  
 INSERT INTO用户（user_name，user_role，user_skill，rating）VALUES（？，？，？ ）？; 
 <   sql：param     value   =  $ {param.name}    /  >  
 <   sql：param    < span class =code-attribute> value   =  $ {param.role}    /  >  
 <   sql：param     value   =  $ {param.skill}    /  > ;  
 <   sql：param     value   =  $ {param .rating}    /  >  
 <   / sql：update  >  
 
 
 <   c：if     test   =  $ {result& gt; = 1} >  
 <   font     size   =  5   颜色  =  green > 恭喜！数据已成功插入
。<   / font   >  
 
 
 <   c：redirect     url   =  NewUser.jsp >  
 <   c：param     name   =  susMsg   值  = 祝贺！数据已成功插入。    /  >  
 <   / c：redirect  >  
 <   / c：if  >  
 
 <   / c：当 >  
 
 <   c：否则 >  < span class =code-keyword><   / c：否则 >  
 
 <   / c：选择 >  
 &l t;   / br  >  <   / c：foreach  >  

HTML编码，代码块。[/ edit]



我尝试过：



我创建了一个表。我想添加新的用户详细信息。如果该用户已经在数据库中，那么它应该已经存在用户名。应该得到一个页面

所有textfileds.and我必须成功地将所有值添加到数据库。



我试过下面的标签也是..

 <   c：if     test   =   $ {param.name eq row.user_name}    xmlns：c   =  #unknown >  
 <   c：if     test   =   $ {param.name ne row.user_name} >  <   / c：if  >  <   / c：if  >  <   / br  >  

解决方案

{dbsource} var = result2 xmlns：sql = ＃unknown >
来自用户的SELECT *;
< / sql：query >

< c：out value =

{param.name} xmlns：c = ＃unknown < span class =code-keyword> / >
< br >


< c：foreach var = row items =

{result2.rows} xmlns：c = ＃unknown >
< c：out value =

<sql:query datasource="${dbsource}" var="result2" xmlns:sql="#unknown">
            SELECT * from Users;
           </sql:query>
           
            <c:out value="${param.name}" xmlns:c="#unknown" />
            <br>
         
         
         <c:foreach var="row" items="${result2.rows}" xmlns:c="#unknown">
         <c:out value="${param.user_name}" /><br>
         
         <c:choose>
         
            <c:when test="${param.name eq row.user_name}"> 
	        <font size="5" color="red">UserName Already Exists .Please choose different name</font><br>
	        <a href="NewUser.jsp">Enter Other UserName</a> 
	        </br></c:when> 
          
        
         <c:when test="${param.name ne param.user_name}"> 
         <sql:update datasource="${dbsource}" var="result" xmlns:sql="#unknown">
            INSERT INTO Users(user_name,user_role,user_skill,rating) VALUES (?,?,?,?);
            <sql:param value="${param.name}" />
            <sql:param value="${param.role}" />
            <sql:param value="${param.skill}" />
            <sql:param value="${param.rating}" />
          </sql:update>
      
        
          <c:if test="${result&gt;=1}">
          <font size="5" color="green"> Congratulations ! Data inserted
          successfully.</font>
            
            
           <c:redirect url="NewUser.jsp">
           <c:param name="susMsg" value="Congratulations ! Data inserted successfully." />  
           </c:redirect>   
           </c:if> 
            
           </c:when> 
           
           <c:otherwise></c:otherwise>
           
        </c:choose>    
         </br></c:foreach>

[edit]HTML encode, code blocks.[/edit]

What I have tried:

I created a table.I wanted to add new User Details.If that user is already there in the database it should ask user name already Exists.other wise should get one page
with all textfileds.and I have to add all the values successfully to the database.

I tried with below tags alsoo..

<c:if test="${param.name eq row.user_name}" xmlns:c="#unknown"> 
<c:if test="${param.name ne row.user_name}"></c:if></c:if></br>

解决方案

{dbsource}" var="result2" xmlns:sql="#unknown"> SELECT * from Users; </sql:query> <c:out value="

{param.name}" xmlns:c="#unknown" /> <br> <c:foreach var="row" items="

{result2.rows}" xmlns:c="#unknown"> <c:out value="

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