How to relationalize JSON containing arrays

问题

I am using AWS Glue to read data file containing JSON (on S3). This one is a JSON with data contained in array. I have tried using relationalize() function but it doesn't work on array. It does work on nested JSON but this is not the data format of input.

Is there a way to relationalize JSON with arrays in it?

Input data:

{
    "ID":"1234",
    "territory":"US",
    "imgList":[
        {
            "type":"box"
            "locale":"en-US"
            "url":"boxart/url.jpg"
        },
        {
            "type":"square"
            "locale":"en-US"
            "url":"square/url.jpg"
        }
    ]
}

Code:

dfc = Relationalize.apply(frame = datasource0, staging_path = glue_temp_storage, name = "root", transformation_ctx = "dfc")
dfc.select('root').toDF().show()

Output:

+----+----------+--------+
|ID  |territory |imgList |
+----+----------+--------+
|1234|       US |       1|
+----+----------+--------+

Desired output:

+----+----------+-------------+---------------+---------------+
|ID  |territory |imgList.type |imgList.locale |imgList.url    |
+----+----------+-------------+---------------+---------------+
|1234|       US |       box   |         en-US |boxart/url.jpg |
+----+----------+-------------+---------------+---------------+
|1234|       US |       square|         en-US |square/url.jpg |
+----+----------+-------------+---------------+---------------+

回答1:

Relationalize creates DynamicFrames for each arrays in the JSON document. So you just need to get it and join with the root table:

dfc = Relationalize.apply(frame = datasource0, staging_path = glue_temp_storage, name = "root", transformation_ctx = "dfc")
root_df = dfc.select('root')
imgList_df = dfc.select('root_imgList')

df = Join.apply(root_df, imgList_df, 'imgList', 'id')
df.toDF().show()

来源：https://stackoverflow.com/questions/55251576/how-to-relationalize-json-containing-arrays