使用jq筛选JSON数组元素时出现异常，求正确实现方法

问题情况 #

你用jq筛选JSON数组中statusId == "10270"的元素时踩了坑：

• 执行.issuesData.issues[]能正常输出数组里的每个元素；
• 用.issuesData.issues[].statusId="10270"得到的是所有元素statusId被改成10270的数组，这不是筛选；
• 用.issuesData.issues[].statusId=="10270"得到的是[false, true]的布尔数组，只能看到哪些元素符合，拿不到元素本身。

你需要的是获取符合条件的元素本身，或者它们的key字段，对应的JSON结构如下：

{"issuesData": {"issues": [{"id": 3619364,"key": "AIG-1992","hidden": false,"typeId": "1","summary": "XXXXXX","priorityId": "2","done": false,"assignee": "XXXX","assigneeName": "XXXX","hasCustomUserAvatar": false,"autoUserAvatar": {"letter": "B","color": "#d39c3f"},"color": "#ff0000","epicId": "3557134","epic": "AIG-1","estimateStatisticRequired": false,"statusId": "10370","fixVersions": [120044],"projectId": 49202},{"id": 3617950,"key": "AIG-1938","hidden": false,"typeId": "1","summary": "YYYYYY","priorityId": "2","done": false,"assignee": "YYYY","assigneeName": "YYY","hasCustomUserAvatar": false,"autoUserAvatar": {"letter": "F","color": "#7bc1a1"},"color": "#ff0000","epicId": "3658470","epic": "AIG-574","estimateStatisticRequired": false,"statusId": "10270","fixVersions": [],"projectId": 49202}]}}

错误原因 #

• .issuesData.issues[].statusId="10270"是赋值操作，遍历数组每个元素把statusId改成目标值，返回修改后的数组，不是筛选；
• .issuesData.issues[].statusId=="10270"是逐个判断元素的statusId是否匹配，返回的是每个判断的结果，不是符合条件的元素。

正确操作 #

1. 获取符合条件的完整元素 #

用select()函数筛选，语法如下：

.issuesData.issues[] | select(.statusId == "10270")

执行后直接输出符合条件的元素：

{"id":3617950,"key":"AIG-1938","hidden":false,"typeId":"1","summary":"YYYYYY","priorityId":"2","done":false,"assignee":"YYYY","assigneeName":"YYY","hasCustomUserAvatar":false,"autoUserAvatar":{"letter":"F","color":"#7bc1a1"},"color":"#ff0000","epicId":"3658470","epic":"AIG-574","estimateStatisticRequired":false,"statusId":"10270","fixVersions":[],"projectId":49202}

2. 获取符合条件元素的key字段 #

在筛选后追加提取key的操作：

.issuesData.issues[] | select(.statusId == "10270") | .key

执行后输出：

"AIG-1938"

3. 返回包含符合条件元素的数组 #

如果需要结果是数组形式（哪怕只有一个元素），可以用map()：

.issuesData.issues | map(select(.statusId == "10270"))

执行后输出：

[{"id":3617950,"key":"AIG-1938","hidden":false,"typeId":"1","summary":"YYYYYY","priorityId":"2","done":false,"assignee":"YYYY","assigneeName":"YYY","hasCustomUserAvatar":false,"autoUserAvatar":{"letter":"F","color":"#7bc1a1"},"color":"#ff0000","epicId":"3658470","epic":"AIG-574","estimateStatisticRequired":false,"statusId":"10270","fixVersions":[],"projectId":49202}]

内容的提问来源于stack exchange，提问作者Daniel Ferreira Castro