使用u-sql查询姓名和城市

Question

我需要从嵌套 json 下方过滤名称和城市。

[
    {
        "Employee": [
            {
                "name": "John",
                "Gender": "Male"
            }
        ],
        "Info": {
            "location": {
                "city": "Kuvala",
                "continent": "Asia",
                "country": "Singapore"
            }
        }
    },
    {
        "Employee": [
            {
                "name": "Mike",
                "Gender": "Male"
            }
        ],
        "Info": {
            "location": {
                "city": "Dhabi",
                "continent": "Asia",
                "country": "Dubai"
            }
        }
    }
]

我的代码

CREATE ASSEMBLY IF NOT EXISTS [Newtonsoft.Json] FROM @"/Assemblies/Newtonsoft.Json.dll";
CREATE ASSEMBLY IF NOT EXISTS [Microsoft.Analytics.Samples.Formats] FROM @"/Assemblies/Microsoft.Analytics.Samples.Formats.dll";

REFERENCE ASSEMBLY [Newtonsoft.Json];
REFERENCE ASSEMBLY [Microsoft.Analytics.Samples.Formats];

USING Microsoft.Analytics.Samples.Formats.Json;

DECLARE @InputFile string = @"/Source/example.blob";
DECLARE @output string = @"/Output/output.csv";

@json  =
    EXTRACT Employee String,
            Info String
    FROM @InputFile
    USING new Microsoft.Analytics.Samples.Formats.Json.JsonExtractor("*");

@CreateJSONTuple =
    SELECT   JsonFunctions.JsonTuple(Employee) AS EmployeeData,
             JsonFunctions.JsonTuple(Info) AS InfoData
    FROM @json;

@result =
    SELECT EmployeeData["name"] AS Name,
           JsonFunctions.JsonTuple(InfoData, "location") AS LocationData
    FROM @CreateJSONTuple;

OUTPUT @result
TO @output
USING Outputters.Csv(outputHeader : true, quoting : true);

我收到错误消息，说无法从 'Microsoft.Analytics.Types.Sql.SqlArray' 转换为 'string' 请帮忙。

请帮助我从中获取名称，城市。 这应该输出： 约翰·瓦拉拉 迈克·扎比

Answer 1

我认为您收到此错误是因为 Employee 元素的内容被定义为一个数组：

"Employee": [
        {
            "name": "Mike",
            "Gender": "Male"
        }
    ]

尝试将 Employee 元素更改为如下内容：

"Employee": {
            "name": "Mike",
            "Gender": "Male"
        }

更新

看来您可能需要对数组项执行 JsonTuple，所以这可能有效：

@result =
SELECT JsonFunctions.JsonTuple(EmployeeData[0])["name"] AS Name,
       JsonFunctions.JsonTuple(InfoData, "location") AS LocationData
FROM @CreateJSONTuple;

需要注意的是，如果 Employee 数组可能包含多个项目，您可能需要使用 Cross Apply Explode。

更新 2

不幸的是，这是我能想到的最后一件事。尝试替换：

@CreateJSONTuple =
SELECT   JsonFunctions.JsonTuple(Employee) AS EmployeeData,
         JsonFunctions.JsonTuple(Info) AS InfoData
FROM @json;

@result =
SELECT EmployeeData["name"] AS Name,
       JsonFunctions.JsonTuple(InfoData, "location") AS LocationData
FROM @CreateJSONTuple;

有了这个：

@CreateJSONTuple =
SELECT   JsonFunctions.JsonTuple(Employee).Values AS EmployeeData,
         JsonFunctions.JsonTuple(Info) AS InfoData
FROM @json;
@result =
SELECT JsonFunctions.JsonTuple(employee)["name"] AS Name,
       JsonFunctions.JsonTuple(InfoData, "location") AS LocationData
FROM @CreateJSONTuple
CROSS APPLY
    EXPLODE(EmployeeData) AS employees(employee) ;

希望对你有帮助！