如何使用JQ将数组流转换为CSV？解决转换报错问题

我通过JQ过滤JSON文件得到了一组数组流数据，想转成CSV文件，执行命令cat file.json | jq '.[]| join(",")'时弹出错误：jq: error (at <stdin>:8): Cannot iterate over string ("https://lo...)。

输入的数组流内容：

[
  "https://localhost/rundeck/project/Enterprise/execution/show/228",
  "succeeded",
  "Enterprise",
  "2020-04-19T03:00:01Z",
  "2020-04-19T03:13:17Z",
  "job_particion"
]
[
  "https://localhost/rundeck/project/Enterprise/execution/show/824",
  "succeeded",
  "Enterprise",
  "2020-09-01T04:15:00Z",
  "2020-09-01T04:15:02Z",
  "job_scheduler"
]
[
  "https://localhost/rundeck/project/Enterprise/execution/show/822",
  "succeeded",
  "Enterprise",
  "2020-09-01T03:45:00Z",
  "2020-09-01T03:45:06Z",
  "job_system"
]
[
  "https://localhost/rundeck/project/Enterprise/execution/show/823",
  "succeeded",
  "Enterprise",
  "2020-09-01T04:00:00Z",
  "2020-09-01T04:00:25Z",
  "job_operator"
]
[
  "https://localhost/rundeck/project/Enterprise/execution/show/821",
  "succeeded",
  "Enterprise",
  "2020-09-01T03:30:00Z",
  "2020-09-01T03:30:10Z",
  "job_aplication"
]

错误原因 #

你的命令逻辑有误：.[]会把数组内的每个元素（比如URL字符串）单独提取出来，然后尝试对字符串执行join(",")——但join是数组专属方法，字符串无法调用该方法，因此触发“不能遍历字符串”的错误。

解决方案 #

需要直接对每个完整数组调用join(",")，无需遍历数组内元素：

基础转换命令 #

cat file.json | jq 'join(",")'

标准CSV转换（推荐） #

如果要生成符合规范的CSV（自动处理含逗号的字段），使用jq内置的@csv过滤器，它会自动给需要的字段添加引号：

cat file.json | jq '@csv'

执行后输出的标准CSV内容：

"https://localhost/rundeck/project/Enterprise/execution/show/228","succeeded","Enterprise","2020-04-19T03:00:01Z","2020-04-19T03:13:17Z","job_particion"
"https://localhost/rundeck/project/Enterprise/execution/show/824","succeeded","Enterprise","2020-09-01T04:15:00Z","2020-09-01T04:15:02Z","job_scheduler"
"https://localhost/rundeck/project/Enterprise/execution/show/822","succeeded","Enterprise","2020-09-01T03:45:00Z","2020-09-01T03:45:06Z","job_system"
"https://localhost/rundeck/project/Enterprise/execution/show/823","succeeded","Enterprise","2020-09-01T04:00:00Z","2020-09-01T04:00:25Z","job_operator"
"https://localhost/rundeck/project/Enterprise/execution/show/821","succeeded","Enterprise","2020-09-01T03:30:00Z","2020-09-01T03:30:10Z","job_aplication"

内容的提问来源于stack exchange，提问作者anywhere