从 mysql 表中检索所有行，但首先将它们分组以删除重复

Question

我正在从表中检索所有记录以在 php 页面上回显它们，问题是表中重复的 3 列具有相似值的行，有人可以帮我写这段代码吗？我需要分组什么？该组仅检索到一行，请回复。分组的字段越来越重复，添加新记录的字段是secondarySubject和secondaryGrade

我得到的结果是：

---------------------------------

2012-2013 School ABC A-Level 
in science A

2012-2013 School ABC A-Leve
 in maths B

2012-2013 School ABC A-Level
 in Eng C
-----------------------------------

我想要的是

----------------

2012-2013 School ABC A-Level
in science A
in maths B
in Eng C
-----------------------



$result2 = $db->query('

SELECT *

FROM secondaryEducation

WHERE userID = "'.$graduateID.'"

ORDER BY secondaryFinishDate DESC

');

$html .= '<h2>Secondary Education: '.$option.'</h2>';

    while($row = mysql_fetch_assoc($result2))

    {



        $startYear = formatDate($row['secondaryStartDate'], 'Y');

        $finishYear = formatDate($row['secondaryFinishDate'], 'Y');

        if (!empty($row['secondaryGrade']))

            $secondaryGrade = getSecondaryGradeName($row['secondaryGrade']);

        else

            $secondaryGrade = $row['secondaryGradeCustom'];

        if (!empty($row['secondarySubject']))

            $secondarySubject = getSecondarySubjectName($row['secondarySubject']);

        else

            $secondarySubject = $row['secondarySubjectCustom'];

            $score = $row['score'];

            $secondaryLevel = getSecondaryLevelName($row['secondaryLevel']);
            $levelID = getSecondaryLevelID($row['secondaryLevel']);
        if($levelID!=='7')
        {

        $html .= '



            <div class="secondaryListing">

                <div><strong>'.$startYear.' - '.$finishYear.' '.stripslashes($row['secondarySchool']).'</strong></div>

                <div>'.$secondaryLevel.' in '.$secondarySubject.' - '.stripSlashes($secondaryGrade).'</div>

            </div><!-- End education listing -->';
        }

Answer 1

就在while循环之前，创建一个数组：

$schools = array();
while($row = mysql_fetch_assoc($result2))
...

不是附加到$html，而是将字符串添加到$schools 关联数组：

if($levelID!=='7')
{
    $schools[$startYear.' - '.$finishYear.' '.stripslashes($row['secondarySchool']) . ' ' . $secondaryLevel][]=' in '.$secondarySubject.' - '.stripSlashes($secondaryGrade);
}

最后，迭代$schools 关联数组并将字符串附加到$html：

foreach($schools as $group => $entries)
{
    $html .= '<div class="secondaryListing"><div><strong>'.$group.'</strong></div>';
    foreach($entries as $entry) {
        $html .= '<div>'.$entry.'</div>';
    }
    $html .='</div><!-- End education listing -->';
}