apoc.convert.getJsonPropertyMap
Function APOC Core
apoc.convert.getJsonPropertyMap(node,key[,'json-path', 'path-options']) - converts serialized JSON in property back to map
Signature
apoc.convert.getJsonPropertyMap(node :: NODE?, key :: STRING?, path = :: STRING?, pathOptions = null :: LIST? OF STRING?) :: (MAP?)
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.getJsonPropertyMap(p, "json") AS output;
Output |
---|
{a: [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.getJsonPropertyMap(n, 'prop', '$.columns.col2') AS output;
output |
---|
{ "_id": "772col2" } |
or, with custom path options:
MATCH (n:JsonPathNode) RETURN apoc.convert.getJsonPropertyMap(n, 'prop', '$.columns.col2', ['ALWAYS_RETURN_LIST']) AS path
Failed to invoke function apoc.convert.getJsonPropertyMap : Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of java.util.LinkedHashMap<java.lang.Object,java.lang.Object> out of START_ARRAY token at [Source: UNKNOWN; line: -1, column: -1] |
---|
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.getJsonPropertyMap(n, 'prop', '$', []) ELSE 0 END AS value