我正在开发一个连接第三方CakePHP API系统的应用程序。 以下是网址的示例输出：
https://<server>/api/events.json
输出：
{"events":[{"Event":{"Id":"11902","MonitorId":"5","Name":"New Event","Cause":"Continuous","StartTime":"2016-08-15 17:10:00","EndTime":null,"Width":"2304","Height":"1296","Length":"319.81","Frames":"1600","AlarmFrames":"0","TotScore":"0","AvgScore":"0","MaxScore":"0","Archived":"0","Videoed":"0","Uploaded":"0","Emailed":"0","Messaged":"0","Executed":"0","Notes":""},"thumbData":""},{"Event":{"Id":"11903","MonitorId":"7","Name":"New Event","Cause":"Continuous","StartTime":"2016-08-15 17:10:00","EndTime":"2016-08-15 17:11:00" ,"Width":"1280","Height":"720","Length":"316.73","Frames":"1900","AlarmFrames":"0","TotScore":"0","AvgScore":"0","MaxScore":"0","Archived":"0","Videoed":"0","Uploaded":"0","Emailed":"0","Messaged":"0","Executed":"0","Notes":""},"thumbData":""}
请注意，在某些情况下，EndTime字段为空，在某些情况下则不是。我现在想要创建一个只返回EndTime为空的字段的URL。
API允许使用命名过滤器。例如：
https://<server>/api/events/index/EndTime >=: 2016-11-07 10:10:10.json
使用EndTime＆gt;准确返回所有值指定的值。
如何要求EndTime = null？
我试过了：
https://<server>/api/events/index/EndTime =: null.json
这不起作用（也尝试过引号）
感谢