, 각 테이블 행에 각 개별 JSON 요소에 사용하려면, recursive CTE를 사용해야합니다 :
WITH RECURSIVE
raw_json as (
SELECT
*
FROM
(VALUES
(1,
'{
"customerId": "12345",
"orders": [
{
"orderId": "54321",
"lineItems": [
{
"productId": "abc",
"qty": 3
},
{
"productId": "def",
"qty": 1
}
]
}
]
}'::json),
(2,
'{
"customerId": "678910",
"artibitraryLevel": {
"orders": [
{
"orderId": "55345",
"lineItems": [
{
"productId": "abc",
"qty": 3
},
{
"productId": "ghi",
"qty": 10
}
]
}
]
}
}'::json)
) a(id,sample_json)
),
json_recursive as (
SELECT
a.id,
b.k,
b.v,
b.json_type,
case when b.json_type = 'object' and not (b.v->>'customerId') is null then b.v->>'customerId' else a.customer_id end customer_id, --track any arbitrary id when iterating through json graph
case when b.json_type = 'object' and not (b.v->>'orderId') is null then b.v->>'orderId' else a.order_id end order_id,
case when b.json_type = 'object' and not (b.v->>'productId') is null then b.v->>'productId' else a.product_id end product_id
FROM
(
SELECT
id,
sample_json v,
case left(sample_json::text,1)
when '[' then 'array'
when '{' then 'object'
else 'scalar'
end json_type, --because choice of json accessor function depends on this, and for some reason postgres has no built in function to get this value
sample_json->>'customerId' customer_id,
sample_json->>'orderId' order_id,
sample_json->>'productId' product_id
FROM
raw_json
) a
CROSS JOIN LATERAL (
SELECT
b.k,
b.v,
case left(b.v::text,1)
when '[' then 'array'
when '{' then 'object'
else 'scalar'
end json_type
FROM
json_each(case json_type when 'object' then a.v else null end) b(k,v) --get key value pairs for individual elements if we are dealing with standard object
UNION ALL
SELECT
null::text k,
c.v,
case left(c.v::text,1)
when '[' then 'array'
when '{' then 'object'
else 'scalar'
end json_type
FROM
json_array_elements(case json_type when 'array' then a.v else null end) c(v) --if we have an array, just get the elements and use parent key
) b
UNION ALL --recursive term
SELECT
a.id,
b.k,
b.v,
b.json_type,
case when b.json_type = 'object' and not (b.v->>'customerId') is null then b.v->>'customerId' else a.customer_id end customer_id,
case when b.json_type = 'object' and not (b.v->>'orderId') is null then b.v->>'orderId' else a.order_id end order_id,
case when b.json_type = 'object' and not (b.v->>'productId') is null then b.v->>'productId' else a.product_id end product_id
FROM
json_recursive a
CROSS JOIN LATERAL (
SELECT
b.k,
b.v,
case left(b.v::text,1)
when '[' then 'array'
when '{' then 'object'
else 'scalar'
end json_type
FROM
json_each(case json_type when 'object' then a.v else null end) b(k,v)
UNION ALL
SELECT
a.k,
c.v,
case left(c.v::text,1)
when '[' then 'array'
when '{' then 'object'
else 'scalar'
end json_type
FROM
json_array_elements(case json_type when 'array' then a.v else null end) c(v)
) b
)
그런 다음 임의의 ID로 중 하나를 수행 할 수 있습니다 합계 "수량". ..
SELECT
customer_id,
sum(v::text::integer)
FROM
json_recursive
WHERE
k = 'qty'
GROUP BY
customer_id
또는 당신이 "LINEITEM"개체를 얻을 당신이 원하는대로 그들을 조작 할 수 있습니다 :
SELECT
*
FROM
json_recursive
WHERE
k = 'lineItems' and json_type = 'object'
는 색인에 관해서는, 당신은 당신의 원래 테이블의 각 행의 각 JSON 객체에 대한 고유 키를 반환하는 함수에 재귀 쿼리를 적용 할 수 그리고 그것은 당신의 JSON 열을 기능 인덱스를 만들 :
SELECT
array_agg(DISTINCT k)
FROM
json_recursive
WHERE
not k is null