列表中的 Azure 流分析列表

Question

如果 json 数组在列表中，如何从文件列表中获取数据？例如

   {"city":{"id":1851632,"name":"Shuzenji",
"coord":{"lon":138.933334,"lat":34.966671},
"country":"JP",
"cod":"200",
"message":0.0045,
"cnt":38,
"list":[{
        "dt":1406106000,
        "main":{
            "temp":298.77,
            "temp_min":298.77,
            "temp_max":298.774,
            "pressure":1005.93,
            "sea_level":1018.18,
            "grnd_level":1005.93,
            "humidity":87
            "temp_kf":0.26},
        "weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04d"}],
        "clouds":{"all":88},
        "wind":{"speed":5.71,"deg":229.501},
        "sys":{"pod":"d"},
        "dt_txt":"2014-07-23 09:00:00"}
        ]}

如何到达 weather.main？

Answer 1

首先你的 JSON 格式似乎有错误，让我们先修复这些：

{"city":{"id":1851632,"name":"Shuzenji"},
"coord":{"lon":138.933334,"lat":34.966671},
"country":"JP",
"cod":"200",
"message":0.0045,
"cnt":38,
"list":[{
        "dt":1406106000,
        "main":{
            "temp":298.77,
            "temp_min":298.77,
            "temp_max":298.774,
            "pressure":1005.93,
            "sea_level":1018.18,
            "grnd_level":1005.93,
            "humidity":87,
            "temp_kf":0.26},
        "weather":[{"id":804,"main":"Clouds","description":"overcast clouds","icon":"04d"}],
        "clouds":{"all":88},
        "wind":{"speed":5.71,"deg":229.501},
        "sys":{"pod":"d"},
        "dt_txt":"2014-07-23 09:00:00"}
        ]},

湿度行末尾注意逗号，修善寺后第一行关闭记录。

现在，在 JSON 示例中 weather.main，实际上是 list[0].weather[0].main。这是精确获取此值的方法使用 Array and Record 内置函数脱离 JSON 结构：

SELECT
    -- input.list[0].weather[0].main
    WeatherMain = GetRecordPropertyValue(GetArrayElement(GetRecordPropertyValue(GetArrayElement(input.list, 0), 'weather'), 0), 'main')
FROM input

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