apoc.convert.fromJsonList

Details
Syntax	`apoc.convert.fromJsonList(list [, path, pathOptions ])`
Description	Converts the given JSON list into a Cypher `LIST<STRING>`.
Arguments	Name	Type	Description
	`list`	`STRING`	A JSON stringified list.
	`path`	`STRING`	A JSON path expression used to extract a certain part from the list. The default is: ``.
	`pathOptions`	`LIST<STRING>`	JSON path options: ('ALWAYS_RETURN_LIST', 'AS_PATH_LIST', 'DEFAULT_PATH_LEAF_TO_NULL', 'REQUIRE_PROPERTIES', 'SUPPRESS_EXCEPTIONS') The default is: `null`.
Returns	`LIST<ANY>`

Usage examples

The following converts a JSON list into a Cypher list:

RETURN apoc.convert.fromJsonList('[1,2,3]') AS output;

Results
Output
[1, 2, 3]

We can also use JSON path expressions to extract part of a JSON list. For example, the following extracts the name property from a JSON list of objects and returns a list of Cypher strings:

RETURN apoc.convert.fromJsonList('[
  {"name": "Neo4j"},
  {"name": "Graph Data Science Library"},
  {"name": "Bloom"}
]', '.name') AS output;

Results
Output
["Neo4j", "Graph Data Science Library", "Bloom"]

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 we can execute (with default pathOptions):

RETURN apoc.convert.fromJsonList('{ "columns": {
      "col2": {
        "_id": "772col2"
      }
    }
}', '$..columns') AS output;

Results
output
[ {"col2": { "_id": "772col2" }}, null, null ]

or, with custom path options:

RETURN apoc.convert.fromJsonList('{ "columns": {
      "col2": {
        "_id": "772col2"
      }
    }
}', '$..columns', ['ALWAYS_RETURN_LIST']) AS output;

Results
output
[ {"col2": { "_id": "772col2" }} ]

If we try to convert a non-list structure, we’ll get an exception. For example:

RETURN apoc.convert.fromJsonList('{"name": "Neo4j"}') AS output;

Results
Failed to invoke function `apoc.convert.fromJsonList`: Caused by: com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `java.util.ArrayList<java.lang.Object>` out of START_OBJECT token at [Source: (String)"{"name": "Neo4j"}"; line: 1, column: 1]

In this case we should instead use apoc.convert.fromJsonMap.