azure-log-analytics - 如何用kusto查询语言解析json数组

Question

如何在 kusto 查询语言中解析 json 数组。我有一个输出列，它具有 JSON 数组格式的值，如下所示。我需要解析它以获取两列形式的值。

{"count": 14
"value": [
        {
            "Total_Record_Count": 16608,
            "date": "2021-03-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 27254,
            "date": "2021-02-24T00:00:00Z"
        },
        {
            "Total_Record_Count": 6,
            "date": "2021-02-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 26964,
            "date": "2021-01-15T00:00:00Z"
        },
        {
            "Total_Record_Count": 134516,
            "date": "2020-12-18T00:00:00Z"
        },
        {
            "Total_Record_Count": 27345,
            "date": "2020-12-16T00:00:00Z"
        },
        {
            "Total_Record_Count": 521,
            "date": "2020-12-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 4,
            "date": "2020-11-02T00:00:00Z"
        },
        {
            "Total_Record_Count": 6,
            "date": "2020-10-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 1,
            "date": "2020-09-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 3,
            "date": "2020-08-03T00:00:00Z"
        },
        {
            "Total_Record_Count": 18,
            "date": "2020-07-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 18754,
            "date": "2020-06-16T00:00:00Z"
        },
        {
            "Total_Record_Count": 4451898,
            "date": "2020-06-08T00:00:00Z"
        }
    ]}

如何使用输出列名而不是使用完整的 json 数组来实现它。

Answer 1

请参阅下面的示例，该示例使用 mv-expand 运算符将数组分解为行。 https://learn.microsoft.com/en-us/azure/data-explorer/kusto/query/mvexpandoperator

print d = dynamic(
{"count": 14,
"value": [
        {
            "Total_Record_Count": 16608,
            "date": "2021-03-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 27254,
            "date": "2021-02-24T00:00:00Z"
        },
        {
            "Total_Record_Count": 6,
            "date": "2021-02-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 26964,
            "date": "2021-01-15T00:00:00Z"
        },
        {
            "Total_Record_Count": 134516,
            "date": "2020-12-18T00:00:00Z"
        },
        {
            "Total_Record_Count": 27345,
            "date": "2020-12-16T00:00:00Z"
        },
        {
            "Total_Record_Count": 521,
            "date": "2020-12-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 4,
            "date": "2020-11-02T00:00:00Z"
        },
        {
            "Total_Record_Count": 6,
            "date": "2020-10-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 1,
            "date": "2020-09-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 3,
            "date": "2020-08-03T00:00:00Z"
        },
        {
            "Total_Record_Count": 18,
            "date": "2020-07-01T00:00:00Z"
        },
        {
            "Total_Record_Count": 18754,
            "date": "2020-06-16T00:00:00Z"
        },
        {
            "Total_Record_Count": 4451898,
            "date": "2020-06-08T00:00:00Z"
        }
    ]})
| project Value = d.['value'] 
| mv-expand Value
| project Count = tolong(Value.['Total_Record_Count']), Date = todatetime(Value.['date'])

<表类="s-表"><头>计数<日>日期 <正文>44518982020-06-08 00:00:00.0000000187542020-06-16 00:00:00.0000000182020-07-01 00:00:00.000000032020-08-03 00:00:00.000000012020-09-01 00:00:00.000000062020-10-01 00:00:00.000000042020-11-02 00:00:00.00000005212020-12-01 00:00:00.0000000273452020-12-16 00:00:00.00000001345162020-12-18 00:00:00.0000000269642021-01-15 00:00:00.000000062021-02-01 00:00:00.0000000272542021-02-24 00:00:00.0000000166082021-03-01 00:00:00.0000000