SQL/JSON: Fix JSON_QUERY(... WITH CONDITIONAL WRAPPER)

Currently, when WITH CONDITIONAL WRAPPER is specified, array wrappers
are applied even to a single SQL/JSON item if it is a scalar JSON
value, but this behavior does not comply with the standard.

To fix, apply wrappers only when there are multiple SQL/JSON items
in the result.

Reported-by: Peter Eisentraut <peter@eisentraut.org>
Author: Peter Eisentraut <peter@eisentraut.org>
Author: Amit Langote <amitlangote09@gmail.com>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Discussion: https://postgr.es/m/8022e067-818b-45d3-8fab-6e0d94d03626%40eisentraut.org
Backpatch-through: 17
This commit is contained in:
Amit Langote 2024-09-12 09:36:31 +09:00
parent 77761ee5dd
commit e6c45d85dc
3 changed files with 48 additions and 38 deletions

View File

@ -3947,7 +3947,24 @@ JsonPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper, bool *empty,
return (Datum) 0;
}
/* WRAP or not? */
/*
* Determine whether to wrap the result in a JSON array or not.
*
* First, count the number of SQL/JSON items in the returned
* JsonValueList. If the list is empty (singleton == NULL), no wrapping is
* necessary.
*
* If the wrapper mode is JSW_NONE or JSW_UNSPEC, wrapping is explicitly
* disabled. This enforces a WITHOUT WRAPPER clause, which is also the
* default when no WRAPPER clause is specified.
*
* If the mode is JSW_UNCONDITIONAL, wrapping is enforced regardless of
* the number of SQL/JSON items, enforcing a WITH WRAPPER or WITH
* UNCONDITIONAL WRAPPER clause.
*
* For JSW_CONDITIONAL, wrapping occurs only if there is more than one
* SQL/JSON item in the list, enforcing a WITH CONDITIONAL WRAPPER clause.
*/
count = JsonValueListLength(&found);
singleton = count > 0 ? JsonValueListHead(&found) : NULL;
if (singleton == NULL)
@ -3957,10 +3974,7 @@ JsonPathQuery(Datum jb, JsonPath *jp, JsonWrapper wrapper, bool *empty,
else if (wrapper == JSW_UNCONDITIONAL)
wrap = true;
else if (wrapper == JSW_CONDITIONAL)
wrap = count > 1 ||
IsAJsonbScalar(singleton) ||
(singleton->type == jbvBinary &&
JsonContainerIsScalar(singleton->val.binary.data));
wrap = count > 1;
else
{
elog(ERROR, "unrecognized json wrapper %d", (int) wrapper);

View File

@ -541,11 +541,11 @@ SELECT JSON_VALUE(NULL::jsonb, '$');
(1 row)
SELECT
JSON_QUERY(js, '$'),
JSON_QUERY(js, '$' WITHOUT WRAPPER),
JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER),
JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER),
JSON_QUERY(js, '$' WITH ARRAY WRAPPER)
JSON_QUERY(js, '$') AS "unspec",
JSON_QUERY(js, '$' WITHOUT WRAPPER) AS "without",
JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER) AS "with cond",
JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER) AS "with uncond",
JSON_QUERY(js, '$' WITH ARRAY WRAPPER) AS "with"
FROM
(VALUES
(jsonb 'null'),
@ -555,12 +555,12 @@ FROM
('[1, null, "2"]'),
('{"a": 1, "b": [2]}')
) foo(js);
json_query | json_query | json_query | json_query | json_query
unspec | without | with cond | with uncond | with
--------------------+--------------------+--------------------+----------------------+----------------------
null | null | [null] | [null] | [null]
12.3 | 12.3 | [12.3] | [12.3] | [12.3]
true | true | [true] | [true] | [true]
"aaa" | "aaa" | ["aaa"] | ["aaa"] | ["aaa"]
null | null | null | [null] | [null]
12.3 | 12.3 | 12.3 | [12.3] | [12.3]
true | true | true | [true] | [true]
"aaa" | "aaa" | "aaa" | ["aaa"] | ["aaa"]
[1, null, "2"] | [1, null, "2"] | [1, null, "2"] | [[1, null, "2"]] | [[1, null, "2"]]
{"a": 1, "b": [2]} | {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | [{"a": 1, "b": [2]}] | [{"a": 1, "b": [2]}]
(6 rows)
@ -587,10 +587,10 @@ FROM
--------------------+--------------------+---------------------+----------------------+----------------------
| | | |
| | | |
null | null | [null] | [null] | [null]
12.3 | 12.3 | [12.3] | [12.3] | [12.3]
true | true | [true] | [true] | [true]
"aaa" | "aaa" | ["aaa"] | ["aaa"] | ["aaa"]
null | null | null | [null] | [null]
12.3 | 12.3 | 12.3 | [12.3] | [12.3]
true | true | true | [true] | [true]
"aaa" | "aaa" | "aaa" | ["aaa"] | ["aaa"]
[1, 2, 3] | [1, 2, 3] | [1, 2, 3] | [[1, 2, 3]] | [[1, 2, 3]]
{"a": 1, "b": [2]} | {"a": 1, "b": [2]} | {"a": 1, "b": [2]} | [{"a": 1, "b": [2]}] | [{"a": 1, "b": [2]}]
| | [1, "2", null, [3]] | [1, "2", null, [3]] | [1, "2", null, [3]]
@ -681,7 +681,7 @@ LINE 1: SELECT JSON_QUERY(jsonb '[1]', '$' WITH CONDITIONAL WRAPPER ...
SELECT JSON_QUERY(jsonb '["1"]', '$[*]' WITH CONDITIONAL WRAPPER KEEP QUOTES);
json_query
------------
["1"]
"1"
(1 row)
SELECT JSON_QUERY(jsonb '["1"]', '$[*]' WITH UNCONDITIONAL WRAPPER KEEP QUOTES);
@ -940,30 +940,30 @@ FROM
x | y | list
---+---+--------------
0 | 0 | []
0 | 1 | [1]
0 | 1 | 1
0 | 2 | [1, 2]
0 | 3 | [1, 2, 3]
0 | 4 | [1, 2, 3, 4]
1 | 0 | []
1 | 1 | [1]
1 | 1 | 1
1 | 2 | [1, 2]
1 | 3 | [1, 2, 3]
1 | 4 | [1, 2, 3, 4]
2 | 0 | []
2 | 1 | []
2 | 2 | [2]
2 | 2 | 2
2 | 3 | [2, 3]
2 | 4 | [2, 3, 4]
3 | 0 | []
3 | 1 | []
3 | 2 | []
3 | 3 | [3]
3 | 3 | 3
3 | 4 | [3, 4]
4 | 0 | []
4 | 1 | []
4 | 2 | []
4 | 3 | []
4 | 4 | [4]
4 | 4 | 4
(25 rows)
-- record type returning with quotes behavior.
@ -1088,7 +1088,7 @@ CREATE TABLE test_jsonb_constraints (
CONSTRAINT test_jsonb_constraint3
CHECK (JSON_VALUE(js::jsonb, '$.a' RETURNING int DEFAULT '12' ON EMPTY ERROR ON ERROR) > i)
CONSTRAINT test_jsonb_constraint4
CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < jsonb '[10]')
CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) = jsonb '[10]')
CONSTRAINT test_jsonb_constraint5
CHECK (JSON_QUERY(js::jsonb, '$.a' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) > 'a' COLLATE "C")
);
@ -1103,7 +1103,7 @@ Check constraints:
"test_jsonb_constraint1" CHECK (js IS JSON)
"test_jsonb_constraint2" CHECK (JSON_EXISTS(js::jsonb, '$."a"' PASSING i + 5 AS int, i::text AS txt, ARRAY[1, 2, 3] AS arr))
"test_jsonb_constraint3" CHECK (JSON_VALUE(js::jsonb, '$."a"' RETURNING integer DEFAULT 12 ON EMPTY ERROR ON ERROR) > i)
"test_jsonb_constraint4" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER KEEP QUOTES EMPTY OBJECT ON ERROR) < '[10]'::jsonb)
"test_jsonb_constraint4" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER KEEP QUOTES EMPTY OBJECT ON ERROR) = '[10]'::jsonb)
"test_jsonb_constraint5" CHECK (JSON_QUERY(js::jsonb, '$."a"' RETURNING character(5) WITHOUT WRAPPER OMIT QUOTES EMPTY ARRAY ON EMPTY) > ('a'::bpchar COLLATE "C"))
SELECT check_clause
@ -1113,7 +1113,7 @@ ORDER BY 1;
check_clause
----------------------------------------------------------------------------------------------------------------------------------------
(JSON_QUERY((js)::jsonb, '$."a"' RETURNING character(5) WITHOUT WRAPPER OMIT QUOTES EMPTY ARRAY ON EMPTY) > ('a'::bpchar COLLATE "C"))
(JSON_QUERY((js)::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER KEEP QUOTES EMPTY OBJECT ON ERROR) < '[10]'::jsonb)
(JSON_QUERY((js)::jsonb, '$."a"' RETURNING jsonb WITH CONDITIONAL WRAPPER KEEP QUOTES EMPTY OBJECT ON ERROR) = '[10]'::jsonb)
(JSON_VALUE((js)::jsonb, '$."a"' RETURNING integer DEFAULT 12 ON EMPTY ERROR ON ERROR) > i)
(js IS JSON)
JSON_EXISTS((js)::jsonb, '$."a"' PASSING (i + 5) AS int, (i)::text AS txt, ARRAY[1, 2, 3] AS arr)
@ -1143,9 +1143,6 @@ DETAIL: Failing row contains ({"b": 1}, 1, [1, 2]).
INSERT INTO test_jsonb_constraints VALUES ('{"a": 1}', 1);
ERROR: new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint3"
DETAIL: Failing row contains ({"a": 1}, 1, [1, 2]).
INSERT INTO test_jsonb_constraints VALUES ('{"a": 7}', 1);
ERROR: new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint5"
DETAIL: Failing row contains ({"a": 7}, 1, [1, 2]).
INSERT INTO test_jsonb_constraints VALUES ('{"a": 10}', 1);
ERROR: new row for relation "test_jsonb_constraints" violates check constraint "test_jsonb_constraint4"
DETAIL: Failing row contains ({"a": 10}, 1, [1, 2]).

View File

@ -146,11 +146,11 @@ select json_value('{"a": "1.234"}', '$.a' returning int error on error);
SELECT JSON_VALUE(NULL::jsonb, '$');
SELECT
JSON_QUERY(js, '$'),
JSON_QUERY(js, '$' WITHOUT WRAPPER),
JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER),
JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER),
JSON_QUERY(js, '$' WITH ARRAY WRAPPER)
JSON_QUERY(js, '$') AS "unspec",
JSON_QUERY(js, '$' WITHOUT WRAPPER) AS "without",
JSON_QUERY(js, '$' WITH CONDITIONAL WRAPPER) AS "with cond",
JSON_QUERY(js, '$' WITH UNCONDITIONAL ARRAY WRAPPER) AS "with uncond",
JSON_QUERY(js, '$' WITH ARRAY WRAPPER) AS "with"
FROM
(VALUES
(jsonb 'null'),
@ -331,7 +331,7 @@ CREATE TABLE test_jsonb_constraints (
CONSTRAINT test_jsonb_constraint3
CHECK (JSON_VALUE(js::jsonb, '$.a' RETURNING int DEFAULT '12' ON EMPTY ERROR ON ERROR) > i)
CONSTRAINT test_jsonb_constraint4
CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) < jsonb '[10]')
CHECK (JSON_QUERY(js::jsonb, '$.a' WITH CONDITIONAL WRAPPER EMPTY OBJECT ON ERROR) = jsonb '[10]')
CONSTRAINT test_jsonb_constraint5
CHECK (JSON_QUERY(js::jsonb, '$.a' RETURNING char(5) OMIT QUOTES EMPTY ARRAY ON EMPTY) > 'a' COLLATE "C")
);
@ -353,7 +353,6 @@ INSERT INTO test_jsonb_constraints VALUES ('1', 1);
INSERT INTO test_jsonb_constraints VALUES ('[]');
INSERT INTO test_jsonb_constraints VALUES ('{"b": 1}', 1);
INSERT INTO test_jsonb_constraints VALUES ('{"a": 1}', 1);
INSERT INTO test_jsonb_constraints VALUES ('{"a": 7}', 1);
INSERT INTO test_jsonb_constraints VALUES ('{"a": 10}', 1);
DROP TABLE test_jsonb_constraints;