我有一个包含两个字段的数据库表，subject_id和teacher_id。subject_id字段中的数字表示数学、科学、英语等科目。teacher_id字段代表不同的教师。他们一起出现在同一行意味着老师1教科目2，或者在不同的行，老师1教主题5，或者在另一行，老师4教主题2，等等。这是一种多对多的关系。
从数据库中查询后，我得到了一个如下结构的数组：
Array
(
[0] => Array
(
[first_name] => bob
[subject_en_name] => italian
)
[1] => Array
(
[first_name] => bob
[subject_en_name] => japanese
)
[2] => Array
(
[first_name] => bob
[subject_en_name] => korean
)
[3] => Array
(
[first_name] => sally
[subject_en_name] => math
)
[4] => Array
(
[first_name] => sally
[subject_en_name] => GMAT
)
)
我需要筛选名字，然后打印出一个句子，比如：
Bob teaches italian, japanese, korean...
Sally teaches math, GMAT...
使用foreach结构
foreach ($teacher_object as $t_object)
{
echo $t_object['first_name'] . " teaches " . $t_object['subject_en_name'] . "<br>";
}
我只能管理这些打印输出：
bob teaches italian
bob teaches japanese
bob teaches korean
sally teaches math
sally teaches GMAT
有没有一个php函数可以帮助我对数组进行排序？其他解决方案？
首先重新排列您的数组，这样您就有了一个以教师名称为索引、以类为子数组的新数组：
$teaches = array();
foreach ($teacher_object as $t_object) {
$teaches[$t_object['first_name']][] = $t_object['subject_en_name'];
}
新阵列将如下所示：
Array
(
[bob] => Array
(
[0] => italian
[1] => japanese
[2] => korean
)
[sally] => Array
(
[0] => math
[1] => GMAT
)
)
现在您有了一个更容易循环的数组。类似这样的东西：
foreach($teaches AS $teacher => $classes) {
echo $teacher . " teaches " . implode(", ",$classes) . "<br/>";
}
给你。。。
bob teaches italian, japanese, korean
sally teaches math, GMAT