Is this possible to have a node property as json raw string and to filter on it with cypher ?
I have a node with some defined properties and metadata (json raw string).
I would like to select or filter on those metadata property.
This is something like this :
START movie=node:TYPE_INDEX(Type = 'MOVIE') // Start with the reference
MATCH movie-[t:TAG]->tag
WHERE collect(movie.Metadata).RatingPress > 3
RETURN distinct movie.Label
And metadata are something like this :
{"RatingPress" : "0","RatingSpectator" : 3"}
I have expected to use collect function in order to call the property like this :
collect(movie.Metadata).RatingPress
But, of course it fails...
Is this a way to bind some json string from a node property with cypher ?
Thanks for your help
That's going against the principles of properties. Why not set the properties in the JSON metadata directly on the node?
But to answer your question:
No, cypher has no knowledge about JSON.
We treat the entire Node as a JSON blob. Since Neo4j doesn't support hierarchical properties, we flatten out the JSON into delimited property names on save and unflatten them on read. You can then form Cypher queries on (for example) property name "foo.bar.baz". The queries tend to look a bit funky because you'll need to quote them using single back quotes, but it works.
Related
I have a json object in my typescript which is returned from server side. One of the keys is dynamic. How do I parse and extract the value for that key.
Ex: serverResponse.detailsLMN.allList
Ex :serverResponse.detailsLMN.deleteList
In the above , 'LMN' is dynamic.
It can be serverResponse.detailsLMN.allList or serverResponse.detailsPQR.allList.
Assuming,
const temp = 'LMN' or 'PQR', how can I use temp to parse JSON object here.
Like : serverResponse.details{temp}.allList
Not sure if I understood your question correctly. But try doing
let data = JSON.parse(serverResponse);
((JSON.stringify(serverResponse)).includes("LMN")) ? serverResponse.detailsLMN.allList
: serverResponse.detailsPQR.allList
^The above code is the same as the if statement. If you don't know the ES6 ternary conditional statement then here's a link:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator
To parse, simply use JSON.parse(). To extract the value, since I can't see the format of the output, it's better to console.log(serverResponse) the whole response and then walk through the Object in Chrome console to see how to get to your specific value.
It appears that the standard Apache NiFi readers/writers can only parse JSON input based on Avro schema.
Avro schema is limiting for JSON, e.g. it does not allow valid JSON properties starting with digits.
JoltTransformJSON processor can help here (it doesn't impose Avro limitations to how the input JSON may look like), but it seems that this processor does not support batch FlowFiles. It is also not based on the readers and writers (maybe because of that).
Is there a way to read arbitrary valid batch JSON input, e.g. in multi-line form
{"myprop":"myval","12345":"12345",...}
{"myprop":"myval2","12345":"67890",...}
and transform it to other JSON structure, e.g. defined by JSON schema, and e.g. using JSON Patch transformation, without writing my own processor?
Update
I am using Apache NiFi 1.7.1
Update 2
Unfortunately, #Shu's suggestion did work. I am getting same error.
Reduced the case to a single UpdateRecord processor that reads JSON with numeric properties and writes to a JSON without such properties using
myprop : /data/5836c846e4b0f28d05b40202
mapping. Still same error :(
it does not allow valid JSON properties starting with digits?
This bug NiFi-4612 fixed in NiFi-1.5 version, We can use AvroSchemaRegistry to defined your schema and change the
Validate Field Names
false
Then we can have avro schema field names starting with digits.
For more details refer to this link.
Is there a way to read arbitrary valid batch JSON input, e.g. in multi-line form?
This bug NiFi-4456 fixed in NiFi-1.7, if you are not using this version of NiFi then we can do workaround to create an array of json messages with ,(comma delimiter) by using.
Flow:
1.SplitText //split the flowfile with 1 line count
2.MergeRecord //merge the flowfiles into one
3.ConvertRecord
For more details regards to this particular issues refer to this link(i have explained with the flow).
I got an anonymous array which I want to deserialize, here the example of the first array object
[
{ "time":"08:55:54",
"date":"2016-05-27",
"timestamp":1464332154807,
"level":3,
"message":"registerResourcePath ('', '/sap/bc/ui5_ui5/ui2/ushell/resources/')",
"details":"","component":"sap.ui.ModuleSystem"},
{"time":"08:55:54","date":"2016-05-27","timestamp":1464332154808,"level":3,"message":"URL prefixes set to:","details":"","component":"sap.ui.ModuleSystem"},
{"time":"08:55:54","date":"2016-05-27","timestamp":1464332154808,"level":3,"message":" (default) : /sap/bc/ui5_ui5/ui2/ushell/resources/","details":"","component":"sap.ui.ModuleSystem"}
]
I tried deserializing using CL_TREX_JSON_SERIALIZER, but it is corrupt and does not work with my JSON, here is why
Then I tried /UI2/CL_JSON, but it needs a "structure" that perfectly fits the object given by the JSON Object. "Structure" means in my case an internal table of objects with the attributes time, date, timestamp, level, messageanddetails. And there was the problem: it does not properly handle references and uses class description to describe the field assigned to the field-symbol. Since I can not have a list of objects but only a list of references to objects that solution also doesn't works.
As a third attempt I tried with the CALL TRANSFORMATION as described by Horst Keller, but with this method I was not able to read in an anonymous array, and here is why
My major points:
I do not want to change the JSON, since that is what I get from sap.ui.log
I prefere to use built-in functionality and not a thirdparty framework
Your problem comes out not from the anonymity of array, but from the awkwardness of SAP JSON (De)serializer, which doesn't respect double quotes, which enclose JSON attributes. The issue is thoroughly described in this answer.
If you don't want to change your JSON on-the-fly, the only way you have is to change CL_TREX_JSON_DESERIALIZER class like this.
/UI5/CL_JSON_PARSER parses JSONs with unknown format.
Note that it's got "for internal use" written on it so many times that you probably should take it seriously and clone its code to fixate it.
I am returning some xml structure as json using the built-in MarkLogic json module. For the most part it does what I expect. However, when an element marked as an array is empty, it returns an empty string instead of an empty array. Here is an example:
xquery version "1.0-ml";
import module namespace json = "http://marklogic.com/xdmp/json"
at "/MarkLogic/json/json.xqy";
let $config := json:config("custom")
return (
map:put( $config, "array-element-names", ("item") ),
json:transform-to-json(<result>
<item>21</item>
<item>22</item>
<item>23</item>
</result>, $config),
json:transform-to-json(<result></result>, $config))
Result:
{"result":{"item":["21", "22", "23"]}}
{"result":""}
I would expect an empty array if there were no items matching in the array-element-name called "item". i.e.
{"result":{"item":[]}}
Is there some way to configure it so it knows the element is required ?
No - it will not create anything that is not there. In your case, what if the XML was more complex. There is no context of 'where' such an element might live - so it could not create it even if it wanted to.
Solution is to repair the content if needed by adding one element - or transforming it into the json-basic namespace - where those elements live inside of of an element noted as an array (which can be empty) - or third, use an XSD to hint to the processor what to do . But that would still need a containing element for the 'array' - and then the items would be minOccurance=0. But if this is the case, then repair and transform into the json/basic namespace is probably nice and simple for your example.
I am trying to serialize some Clojure data structure into a persistent database, and I currently use Chesire for that purpose.
Let's say I have a map that contains namespaced keywords like the following :
{:cemerick.friend/identity {:current friend, :authentications {friend {:identity friend, :roles #{:clojure-cms.handler/user}}}}}
It gets serialized into JSON, like that :
{"cemerick.friend/identity":{"current":"friend","authentications":{"friend":{"identity":"friend","roles":["clojure-cms.handler/user"]}}}}
When reading it back and serializing (with keywordization (parse-string data true)), I get back the following :
{:cemerick.friend/identity {:current friend, :authentications {:friend {:identity friend, :roles [clojure-cms.handler/user]}}}}
How can I parse this JSON with and get the same data as the original ?
Note : this question gives some context to what I am trying to achieve.
Looking at the tests in Chesire, it's quite obvious that the optional keyword parameter to parse-string will affect all name attributes in a JSON object, value attributes like the namespaced keyword in your example are not affected. Actually, your problem is two-fold: the original set is also not converted back correctly.
For the set problem, what you could do is to write a custom decoder as described in the Chesire documentation.
For the original problem, there is probably no direct way other than to post-process the returned map, find the value to :roles and turn the value into a keyword, like so (untested):
(defn postprocess-json [authmap]
(update-in authmap [:authentications :friend :roles] keyword))