数组未显示所有结果 [英] Array not displaying all results

问题描述

这也许就是为什么我在其他区域遇到问题的原因，但是输出该区域会给 m_id 一个空结果.该文件多次使用，并正确显示了所有其他字段的数据，但使用的主字段 m_id 未显示其ID号.

This maybe the reason why I'm having problems in other areas, but which outputting the area its giving an empty result for m_id. the filed it used multiple times and is correctly displaying data for all the other fields but the main field m_id that is used is not showing its ID number.

$res = mysql_query("SELECT *, DATE_FORMAT(sm.m_lld,'%m/%d/%y') 
                    AS m_lld_formatted 
                    FROM social_members sm
                    JOIN social_meminfo smi ON (sm.m_id = smi.m_id)
                    LEFT OUTER JOIN social_memtext smt ON (sm.m_id = smt.m_id)
                    WHERE sm.m_user = '".mysql_real_escape_string($en['user'])."'");            
if (mysql_num_rows($res) == 0) call404();
$line = mysql_fetch_assoc($res);
foreach ($line as $key => $value) {
        $en['m'.$key] = str_replace("\n",'<br/>',stripslashes($value));
        }

echo '<pre>'; print_r($line); echo '</pre>';
echo $en['mm_id'];

好的，我想我知道发生了什么事.当我为social_memtext做一个LEFT OUTER JOIN时，如果该表没有找到m_id的结果，即使它存在于其他两个表中，它也不会显示m_id的值.反正有解决办法吗?查找时，m_id在social_members和_meminfo中始终具有一个值/行

Okay I think I see what's happening. When I do a LEFT OUTER JOIN for social_memtext if that table finds no results for m_id it does not display a value for m_id even though its present in the other two tables. Is there anyway to fix that? m_id will always have a value/row in social_members and _meminfo when looked up

推荐答案

来自:如果结果的两个或更多列具有相同的字段名称，则最后一列优先.

If two or more columns of the result have the same field names, the last column will take precedence.

您要从3个联接中选择所有内容，并且在每个表中m_id具有相同的名称. 这意味着结果集中有3个m_id，最后一个来自左联接表social_memtext，如果该表中没有给定m_id的对应行，则为NULL.

You are selecting everything out of 3 joins and in every table m_id has the same name. Which means there are 3 m_id's in your resultset, last one being from the left joined table social_memtext, which will be NULL if there is no corresponding row in that table for given m_id.

要获得所需的m_id，请在SELECT中添加一个别名，并将该别名用于php中的数组索引.

To get your expected m_id add an alias in SELECT and use that alias for array index in php.

SELECT *, DATE_FORMAT(sm.m_lld,'%m/%d/%y') 
                AS m_lld_formatted,
          sm.m_id as mem_id
...

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