如何将结构数组传递到用户定义的函数中（使用标准SQL）？
首先，一些上下文：
表架构：
id STRING
customer STRING
request STRUCT<
headers STRING
body STRING
url STRING
>
response STRUCT<
size INT64
body STRING
>
outgoing ARRAY<
STRUCT<
request STRUCT<
url STRING,
body STRING,
headers STRING
>,
response STRUCT<
size INT64,
body STRING
>
>
>
用户定义的功能：
CREATE TEMPORARY FUNCTION extractDetailed(
customer STRING,
request STRUCT<
headers STRING,
body STRING
>,
outgoing ARRAY<
STRUCT<
request STRUCT<url STRING>,
response STRUCT<body STRING>
>
>
)
RETURNS STRING
LANGUAGE js AS """
""";
SELECT extractDetailed(customer, STRUCT(request.headers, request.body), outgoing)
FROM request_logs
关于我的问题：我似乎无法弄清楚如何选择一部分outgoingARRAY，并将其作为数组传递给用户定义的函数。
实际上，我正在尝试模拟以下用户定义的函数调用：
extractDetailed(
"customer id",
{ "headers": "", "body": "" },
[
{
"request": { "url": "" },
"response": { "body": "" }
},
{
"request": { "url": "" },
"response": { "body": "" }
}
]
);
最近，我偶然发现了一些可能有助于解锁的文档，但我似乎无法弄清楚如何使其合适。我真的为此感到挣扎，并且希望能为解决该问题提供帮助。
请尝试以下。它从数组中解析所需的和平，并在传递给函数之前将它们放回到新的数组中，以使其与征兆匹配
CREATE TEMPORARY FUNCTION extractDetailed(
customer STRING,
request STRUCT<headers STRING, body STRING>,
outgoing ARRAY<STRUCT<request STRUCT<url STRING>, response STRUCT<body STRING>>>
)
RETURNS STRING
LANGUAGE js AS """
""";
SELECT
extractDetailed(
customer,
STRUCT(request.headers, request.body),
ARRAY(
SELECT STRUCT<request STRUCT<url STRING>,response STRUCT<body STRING>>
(STRUCT(request.url), STRUCT(response.body))
FROM UNNEST(outgoing)
)
) AS details
FROM request_logs
为了进一步“优化”上面的查询并使它更可移植，您可以将提取的部分从原始数组包装到新数组中，并将其包装到单独的SQL UDF中
CREATE TEMPORARY FUNCTION extractParts (
outgoing ARRAY<STRUCT<request STRUCT<url STRING, body STRING, headers STRING>,
response STRUCT<size INT64, body STRING>>>
)
RETURNS ARRAY<STRUCT<request STRUCT<url STRING>, response STRUCT<body STRING>>>
AS ((
SELECT ARRAY(
SELECT STRUCT<request STRUCT<url STRING>,response STRUCT<body STRING>>
(struct(request.url), struct(response.body))
FROM UNNEST(outgoing)
)
));
CREATE TEMPORARY FUNCTION extractDetailed(
customer STRING,
request STRUCT<headers STRING, body STRING>,
outgoing ARRAY<STRUCT<request STRUCT<url STRING>, response STRUCT<body STRING>>>
)
RETURNS STRING
LANGUAGE js AS """
return outgoing.length;
""";
SELECT
extractDetailed(
customer,
STRUCT(request.headers, request.body),
extractParts(outgoing)
) as details
FROM request_logs