Athena 中的 JSON 数组读取不正确，无法取消嵌套

Question

我有一个名为uf的列，它包含一个JSON对象数组。这是一个模型：

[
{"type": "browserId", "name": "", "value": "unknown"},
{"type": "campaign", "name": "", "value": "om_227dec0082a5"},
{"type": "custom", "name": "2351350529", "value": "10148"},
{"type": "custom", "name": "9501713387", "value": "true"},
{"type": "custom", "name": "9517735577", "value": "true"},
{"type": "custom", "name": "9507402548", "value": "true"},
{"type": "custom", "name": "9733902068", "value": "true"}
]

我正试图将其作为儿童记录，但由于某种原因，我找不到正确的方法来首先取消它。然后我注意到我的整个数组被包装到另一个JSON对象中。。

这就是我现在的位置：

我尝试了简单的选择，注意到结果是：

[{type=[{"type": "browserId", "name": "", "value": "ff"}, name=null, value=null}]

该列的定义如下：

{
"Name": "uf",
"Type": "array<struct<type:string,name:string,value:string>>"
}

定义不正确吗？这就是为什么我将整个数组封装在另一个json数组中？

--编辑这是我的csv文件的示例(制表符分隔(。在过去的两天里，我花了两天时间试图看看是否是JSON导致Glue无法将列识别为JSON数组，但我用简单的JSON数组创建了一个新列，该数组被正确分配为array<struct，但在查询后，我遇到了与上述完全相同的问题

timestamp   project_id  campaign_id experiment_id   variation_id    layer_holdback  audience_names  end_user_id uuid    session_id  snippet_revision    user_ip user_agent  user_engine user_engine_version referer global_holdback event_type  event_name  uf  active_views    event_features  event_metrics   event_uuid
1570326511  74971132    11089500404 11097730080 11078120202 false   []  oeu1535997971348r0.4399811351004357     AUTO    6540    5.91.170.0  Mozilla/5.0 (Linux; Android 7.0; SAMSUNG SM-G925F Build/NRD90M) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/9.2 Chrome/67.0.3396.87 Mobile Safari/537.36  js  0.128.0 https://www.zavamed.com/uk/account/ false   view_activated  10832783364 [{"type": "browserId", "name": "", "value": "unknown"}, {"type": "device", "name": "", "value": "mobile"}, {"type": "device_type", "name": "", "value": "phone"}, {"type": "referrer", "name": "", "value": "https://www.google.co.uk/"}, {"type": "source_type", "name": "", "value": "campaign"}, {"type": "currentTimestamp", "name": "", "value": "-1631518596"}, {"type": "offset", "name": "", "value": "-60"}]    []  []  []  4926a5f1-bbb5-4553-9d0b-b26f773fa0f4

Answer 1

我上传了一个示例csv文件到S3，其中包含您提供的内容。然后我在上面运行了一个胶水爬行器

CREATE EXTERNAL TABLE `question_58765672`(
`timestamp` bigint, 
`project_id` bigint, 
`campaign_id` bigint, 
`experiment_id` bigint, 
`variation_id` bigint, 
`layer_holdback` boolean, 
`audience_names` array<string>, 
`end_user_id` string, 
`uuid` string, 
`session_id` string, 
`snippet_revision` bigint, 
`user_ip` string, 
`user_agent` string, 
`user_engine` string, 
`user_engine_version` string, 
`referer` string, 
`global_holdback` boolean, 
`event_type` string, 
`event_name` bigint, 
`uf` string, 
`active_views` array<string>, 
`event_features` array<string>, 
`event_metrics` array<string>, 
`event_uuid` string)
ROW FORMAT DELIMITED 
FIELDS TERMINATED BY 't' 
STORED AS INPUTFORMAT 
'org.apache.hadoop.mapred.TextInputFormat' 
OUTPUTFORMAT 
'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'
LOCATION
's3://__S3_PATH_IN_MY_BUCKET__/'
TBLPROPERTIES (
'CrawlerSchemaDeserializerVersion'='1.0', 
'CrawlerSchemaSerializerVersion'='1.0', 
'UPDATED_BY_CRAWLER'='some-crawler', 
'areColumnsQuoted'='false', 
'averageRecordSize'='553', 
'classification'='csv', 
'columnsOrdered'='true', 
'compressionType'='none', 
'delimiter'='t', 
'objectCount'='1', 
'recordCount'='2', 
'sizeKey'='1109', 
'skip.header.line.count'='1', 
'typeOfData'='file')

正如您所看到的，它将列uf标识为字符串，对此我并不感到惊讶。为了运行此列，我不得不手动将其转换为正确的类型ARRAY(JSON):

SELECT
"timestamp",
_unnested_column
FROM
"stackoverflow"."question_58765672",
UNNEST( CAST(json_parse(uf) AS ARRAY(JSON)) ) AS t(_unnested_column)

结果：

timestamp   _unnested_column
1   1570326511  {"name":"","type":"browserId","value":"unknown"}
2   1570326511  {"name":"","type":"device","value":"mobile"}
3   1570326511  {"name":"","type":"device_type","value":"phone"}
4   1570326511  {"name":"","type":"referrer","value":"https://www.google.co.uk/"}
5   1570326511  {"name":"","type":"source_type","value":"campaign"}
6   1570326511  {"name":"","type":"currentTimestamp","value":"-1631518596"}
7   1570326511  {"name":"","type":"offset","value":"-60"}

然后我想创建一个athena视图，其中，列uf将被正确地广播：

CREATE OR REPLACE VIEW question_58765672_v1_json AS
SELECT
CAST(json_parse(uf) AS ARRAY(JSON)) as uf
-- ALL other columns from your table
FROM 
"stackoverflow"."question_58765672"

然而，我得到了以下错误：

列uf的列类型无效：不支持的配置单元类型：json

我的猜测是，列uf的模式对于胶水爬行器来说太复杂了，无法正确识别它，或者只是不受所用序列号(即'org.apache.hadoop.mapred.TextInputFormat'或'org.apache.hadoop.hive.ql.io.HiveIgnoreKeyTextOutputFormat'(的支持。