我需要一个jsonpath表达式,它返回具有"key"属性的数组的第一个元素。
我正在寻找与此查询相同的结果:
SELECT
j
FROM
jsonb_array_elements(
'[
{"key": "foo"},
{"other": "bar"},
{"key": "baz", "other": "blah"}
]'::JSONB
) j
WHERE
j ? 'key'
LIMIT 1
我的查询目前看起来像这样,但不起作用
SELECT
jsonb_path_query(
'[
{"key": "foo"},
{"other": "bar"},
{"key": "baz", "other": "blah"}
]'::JSONB,
'$[?(@.key)] [0]')
请看这个: https://www.postgresql.org/docs/12/functions-json.html#FUNCTIONS-SQLJSON-PATH-OPERATORS
SELECT
jsonb_path_query_first(
'[
{"key": "foo"},
{"other": "bar"},
{"key": "baz", "other": "blah"}
]'::JSONB,
'$[*] ? (exists (@.key))')
;
jsonb_path_query_first
------------------------
{"key": "foo"}
(1 row)