JQ：ID而不是數字的輸出值​​

Question

這裏是我的輸入JSON：

{ 
    "channels": [ 
     { "id": 1, "name": "Pop"}, 
     { "id": 2, "name": "Rock"} 
    ], 
    "links": [ 
     { "id": 2, "streams": [ {"url": "http://example.com/rock"} ] }, 
     { "id": 1, "streams": [ {"url": "http://example.com/pop"} ] }   
    ] 
} 

這是我想作爲輸出：

"http://example.com/pop" 
"Pop" 
"http://example.com/rock" 
"Rock" 

所以我需要JQ基於與.links[].streams[0].url更換.channels[].id.links[].id

我不知道它是否正確，但這是我如何設法輸出的網址：

(.channels[].id | tostring) as $ids | [.links[]] | map({(.id | tostring): .streams[0].url}) | add as $urls | $urls[$ids] 

"http://example.com/pop" 
"http://example.com/rock" 

問題是，我該如何將.channels[].name添加到它？

Answer 1

有時候你必須要小心，你問什麼，但這樣會產生的結果，你說你想要的：

給定的輸入

.channels[] as $channel 
| $channel.name, 
    (.links[] | select(.id == $channel.id) | .streams[0].url) 

輸出：

"Pop" 
"http://example.com/pop" 
"Rock" 
"http://example.com/rock" 

Answer 2

這裏是一個解決方案其使用減少和setpath從.links製作$urls查找表，然後掃描.channels生成相應的url和名字。

(
    reduce .links[] as $l (
     {}; 
     setpath([ $l.id|tostring ]; [$l.streams[].url]) 
    ) 
) as $urls 
| .channels[] 
| $urls[ .id|tostring ][], .name 

如果多個URL，目前在「流」屬性打印名字之前，這將 全部打印出來。例如如果輸入是

{ 
    "channels": [ 
     { "id": 1, "name": "Pop"}, 
     { "id": 2, "name": "Rock"} 
    ], 
    "links": [ 
     { "id": 2, "streams": [ {"url": "http://example.com/rock"}, 
           {"url": "http://example.com/hardrock"} ] }, 
     { "id": 1, "streams": [ {"url": "http://example.com/pop"} ] }   
    ] 
} 

的輸出將是

"http://example.com/pop" 
"Pop" 
"http://example.com/rock" 
"http://example.com/hardrock" 
"Rock"