php二维数组去除重合数据
Array
(
[0] => Array
(
[knowledge_id] => 1
[tag_id] => 2
)
[1] => Array
(
[knowledge_id] => 1
[tag_id] => 3
)
)
把他里面量相同的[knowledge_id] => 1合并只留一个？？？？？？
