apoc.convert.getJsonProperty
Function APOC Core
apoc.convert.getJsonProperty(node,key[,'json-path', 'path-options']) - converts serialized JSON in property back to original object
Signature
apoc.convert.getJsonProperty(node :: NODE?, key :: STRING?, path = :: STRING?, pathOptions = null :: LIST? OF STRING?) :: (ANY?)
Input parameters
Name | Type | Default |
---|---|---|
node |
NODE? |
null |
key |
STRING? |
null |
path |
STRING? |
|
pathOptions |
LIST? OF STRING? |
[] |
Usage Examples
The examples in this section are based on the following sample graph:
CREATE (:Person {json:'{a:[1,2,3]}'});
MATCH (p:Person)
RETURN apoc.convert.getJsonProperty(p, "json") AS output;
Output |
---|
{a: [1, 2, 3]} |
MATCH (p:Person)
RETURN apoc.convert.getJsonProperty(p, "json", "$.a") AS output;
Output |
---|
[1, 2, 3] |
Moreover, we can customize the Json path options, adding as third parameter (pathOptions
) a list of strings,
where the strings are based on Enum<Option>.
The default value is ["SUPPRESS_EXCEPTIONS", "DEFAULT_PATH_LEAF_TO_NULL"]
. Note that we can also insert []
, that is "without options".
So, with a (n:JsonPathNode {prop: '{"columns":{"col2":{"_id":"772col2"}}}'})
we can execute (with default pathOptions):
MATCH (n:JsonPathNode) RETURN apoc.convert.getJsonProperty(n, 'prop', '$..columns') AS output;
output |
---|
[ {"col2": { "_id": "772col2" }}, null, null ] |
or, with custom path options:
MATCH (n:JsonPathNode) RETURN apoc.convert.getJsonProperty(n, 'prop', '$..columns', ['ALWAYS_RETURN_LIST']) AS output;
Output |
---|
[ {"col2": { "_id": "772col2" }} ] |
Also, we could leverage the apoc.json.validate
procedure (provided with APOC full) to handle incorrectly formatted JSONs by continuing the execution instead of causing it to fail.
For example, given a node (:JsonInvalidNode {prop: '{"foo": [{"baz": 18446744062065078016838}],"baz": 7}'})
,
the following query returns 0 instead of failing due to InputCoercionException: Numeric value (18446744062065078016838) out of range
:
MATCH (n:JsonInvalidNode) WITH n
CALL { WITH n CALL apoc.json.validate(n.prop) YIELD value RETURN collect(value) AS errs }
RETURN CASE errs WHEN [] THEN apoc.convert.getJsonProperty(n, 'prop', '$', []) ELSE 0 END AS value