jq-过滤指定子节点的某个key值

 https://stackoverflow.com/questions/42097410/how-to-check-for-presence-of-key-in-jq-before-iterating-over-the-values

$ jq '.result 
  | .property_history?  
  | .[]
  | select(.event_name == "Sold")  #在指定的key中搜索
  | .date'
"08/30/2004"

JSON:

{  
   "result":{  
      "property_history":[  
         {  
            "date":"01/27/2016",
            "price_changed":0,
            "price":899750,
            "event_name":"Listed",
            "sqft":0
         },
         {  
            "date":"12/15/2015",
            "price_changed":0,
            "price":899750,
            "event_name":"Listed",
            "sqft":2357
         },
         {  
            "date":"08/30/2004",
            "price_changed":0,
            "price":739000,
            "event_name":"Sold",
            "sqft":2357
         }
      ]
   }
}