php怎样获取json的属性值？

今天遇到个问题  外部接口返回的信息是以Json的形式发给我的
结果是这种形式：
[{"userName":"vip0001","meetingId":"606765183","actionType":"webInit","actionTime":"1264735148","userIp":"121.8.221.56"},{"userName":"vip0001","meetingId":"606765183","actionType":"webJoin","actionTime":"1264735149","userIp":"121.8.221.56"},{"userName":"vip0001","meetingId":"606765183","actionType":"serverInit","actionTime":"1264735192","userIp":""},{"userName":"vip0001","meetingId":"606765183","actionType":"serverJoin","actionTime":"1264735192","userIp":"121.8.221.56"},{"userName":"vip0001","meetingId":"606765183","actionType":"serverLeave","actionTime":"1264735229","userIp":"121.8.221.56"}]

现在我要获取userName，meetingId等属性以及他们的值 我想要的结果是 $userName="vip0001";等。。。

因为要放到数据库里面做操作

请问我该怎么做？ 希望高手赐教 谢谢~~

mixed json_decode ( string $json [, bool $assoc = false [, int $depth = 512 ]] )

假设  $Record 保存了json的内容

我是不是要先 解码？  $json=json_decode($Record );

接着 我 echo $json;  页面成空白 没反应了

怎么办啊？

$a =  json_decode ($Record ,true)
echo $a['userName'] ;

  非常感谢大家的帮助 ！！！