Presto：JSON提取多层

Question

我正在尝试在每项服务下提取所检查的名称和状态（其中有多个）。我已经尝试过

TRANSFORM(CAST(JSON_PARSE(json_format(json_extract(json_extract(services_data, '$.services'), '$.inspections'))) AS ARRAY<JSON>), x -> JSON_EXTRACT_SCALAR(x, '$.title')) AS inspection,

有办法吗？我检查了其他相同的问题，但是看不到这些复杂的层。

Answer 1

）

select name, "state"
from example
cross join unnest(cast(json_extract(record, '$.services') as array<json>)) as u(service)
cross join unnest(cast(json_extract(service, '$.inspections') as array(row(name varchar, "state" varchar)))) as x(name,"state");

结果看起来像这样：

name                |   state
------------------------------
Accelerator Pedal   |   green
Accelerator Pedal 2 |   orange
Some dummy name     |   navy

对我来说，就像你追求的一样。