如何使用JSTL sql：query访问重复的列名？ [英] How to access duplicate column names with JSTL sql:query?

问题描述

出于某种原因，这个

    <sql:query dataSource="${ds}" sql="select user.id, user.name as userName, city, state, country, country.name as countryName, latitude, longitude, ip, last_visit from user, country where user.country = country.id order by last_visit desc limit 100" var="result"/>
    <c:forEach var="col" items="${result.columnNames}">
        ${col}, 
    </c:forEach>

产生

id, name, city, state, country, name, latitude, longitude, ip, last_visit,

哪个错了。我专门重命名了查询中的列。我不知道它是如何找到原始字段名称的。那么如何访问user.name的值呢？ $ {row.userName} 不起作用。

Which is wrong. I specifically renamed the columns in the query. I don't know how it found the original field name. So how can I access the value of user.name? ${row.userName} doesn't work.

我正在使用JSTL jstl-1.2.2。

I'm using JSTL jstl-1.2.2.

推荐答案

不确定这是否有用，但我读过使用别名并不总是能正常工作。我见过一个可能的替代方案：

Not sure if this will help, but I've read that using aliases will not always work correctly. A possible alternative I've seen:

 <sql:query dataSource="${ds}" sql="select user.id, concat(user.name,'') as userName, city, state, country, concat(country.name,'') as countryName, latitude, longitude, ip, last_visit from user, country where user.country = country.id order by last_visit desc limit 100" var="result"/>
    <c:forEach var="col" items="${result.columnNames}">
        ${col}, 
    </c:forEach>

希望这会有所帮助。祝你好运。

Hope this helps. Good luck.

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