混合了数组和字典的数据如何使用 Snowpipe 进行 Lateral Flatten？

Question

混合了数组和字典的数据如何使用 Snowpipe 进行 Lateral Flatten？

snowflake-cloud-data-platformflattenlateralsnowflake-task

3

我从一个snowpipe中接收到了两个不同结构的json文件。唯一的区别在于，它有许多嵌套的数组而不是嵌套字典。我正在尝试弄清楚如何将结构1转换为一个最终的表格。我已经成功地将结构2转换为了一个表格，并在下面包含了代码。

我知道我需要使用lateral flatten，但一直没有成功。

**Structure 1: Nested Arrays (Need help on)**
This json lives within a table and in column **JSONTEXT**
[
  {
    "ID": "xxx-xxxx-xxxx xxx-xxx",
    "caseTypeID": "xx-xxxx-xxxx-xxxxx",
    "content": {
      "AccountID": "xx-xxxxx-xxxx-xxxx xxxx-xxxxx",
      "AccountName": "XXXX",
      "Address": {
        "pxObjClass": "Data-Address-Postal"
      },
      "Addresses": [],
      "AllKickoffsComplete": "true",
      "BillingContactList": [],
      "ClientCurrency": "USD",
      "ClientID": "XXXXXX",
      "ClientNSID": "XXXXXXXX-00",
      "ClientName": "XXXXX XXXX Inc.",
      "CompanyPhoneNumber": "XXX-XXX-XXXX",
      "CrmSearchOrg": "XXXX",
      "EEList": [
        {
          "AccountID": "xxx-xxxxx-xxxx-xxxxx xxxx-xxxxx",
          "AccountName": "XXXX",
          "AllowanceList": [
            {
              "AllowanceAmount": "327",
              "AllowanceName": "Car Allowance",
              "pxObjClass": "xxxxx-xxxxx-xxxxx"
]

结构 2：嵌套字典 这个 json 存在于一个表格中，其中的列名为JSONTEXT

[
  {
    "OppID": "xxxx-xxxxx",
    "pxObjClass": "xx-xxxxx-xxxx-xxxxxx",
    "pxPages": {
      "EEList": {
        "Country": "xxx",
        "CountryName": "xxx",
        "Currency": "xxx",
        "EstimatedICPCost": "xxxxxxxxxxx",
        "ICPCurrency": "xxxxx",
        "ICPID": "xxxxxxxxx.",
        "ICPNSID": "xxxx-xx",
        "ICPName": "xxx xx xx.",
        "LocalMonthlySalary": "xxxxxx",
        "MinFee": "xxxx",
        "MonthlyGrossCost": "xxxxx",
        "NewOrRepeatCustomer": "xxxxx",
        "OppCloseDate": "xxx-xxx-xx",
        "OppID": "xxx-xxxx",
        "OpportunityName": "xxx - xxx xxx - xxx - xxxx",
        "ReferralSource": "xxxxxx",
        "pxObjClass": "Index-xx-xxxx-xxxx-xxxxxx",
        "pxSubscript": "EEList"
      }
    },
    "pyID": "xxxxxx",
    "pzInsKey": "xxxx-xxxx-xxxx xxxxx-xxx"
  },
]

这是我为第二个可行结构编写的代码。

create or replace table xxxx
    as select 
    value:ID::varchar as ID,
    value:caseTypeID::varchar as caseTypeID,
    value:content:AccountID::varchar as AccountID,
    value:content:AccountName::varchar as AccountName,
    value:content:AllKickoffsComplete::boolean as AllKickoffsComplete,
    value:content:ClientCurrency::varchar as ClientCurrency,
    value:content:ClientID::varchar as ClientID,
    value:content:ClientNSID::varchar as ClientNSID,
    value:content:ClientName::varchar as ClientName,
    value:content:CompanyAddressCountryName::varchar as CompanyAddressCountryName,
    value:content:CompanyPhoneNumber::varchar as CompanyPhoneNumber,
    value:content:CreateNew::boolean as CreateNew,
    value:content:CrmSearchOrg::varchar as CrmSearchOrg,
    value:content:EEList:AccountID::varchar as EE_AccountID,
    value:content:EEList:AccountName::varchar as EE_AccountName
from new_raw_json, 
    lateral flatten (input =>jsontext);

这是我尝试过的代码，只有当你放置jsontext[Nth]时才能正常工作。

select
    value:ID::varchar as ID,
    value:EEListID::varchar as EEListID,
    value:caseTypeID::varchar as caseTypeID
    from new_raw_json,

    lateral flatten (input => jsontext[0]:content:EEList);

感激任何帮助！

- Bigmoose70

我认为主要问题在于我的表的第一行实际上是一个列表而不仅仅是一个原始的JSON。我正在尝试使用Python重构数据的传输方式！ - Bigmoose70

1个回答

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- Harsh J · Accepted Answer

你可以使用 FLATTEN 来链接多个横向视图，以继续将其展开为嵌套结构（数组中的数组）。

显式定义的方法可能如下所示（这里仅投影了一些列，以说明层次结构）：

SELECT
  outer_object.value:caseTypeID AS caseTypeID,
  outer_object.value:content.AccountID AS parentAccountID,
  eelist_object.value:AccountID AS eeListAccountID,
  allowance_object.value:AllowanceName
FROM
  new_raw_json,
  LATERAL FLATTEN (input => jsontext) outer_object,
  LATERAL FLATTEN (input => outer_object.value:content.EEList) eelist_object,
  LATERAL FLATTEN (input => eelist_object.value:AllowanceList) allowance_object;

请注意，这仅会展开一个已识别的多值路径（List -> EEList -> AllowanceList）。从问题中无法确定是否必须展开所有路径（例如 List -> EEList -> Addresses AND AllowanceList），或者是否可以将其中一些作为最终结果中的 VARIANT（或其他复杂）类型进行存储。

例如，如果需要为EEList下列出的每个地址复制AllowanceList值，则可以通过从两个展开的查询结果进行JOIN（一个链接List -> Addresses，另一个链接List -> EEList -> AllowanceList）来实现。