I'm really new to arangodb (and graph databases). I'm trying to use the sortest_path function:
FOR p in SHORTEST_PATH(imdb_vertices, imdb_edges, "imdb_vertices/349","imdb_vertices/1931", "any", { paths: true})
RETURN p
But the shells returns:
usage of unknown function 'SHORTEST_PATH()'
In the docs I can't find a working example of use of this function.
First of all, the SHORTEST_PATH function has been added in ArangoDB 1.4.11. Can you make sure you are using an ArangoDB server version as least as high as that?
Second, a few examples for SHORTEST_PATH should be here:
https://www.arangodb.org/manuals/1/Aql.html#AqlFunctionsGraph
Related
How to write a user defined function in the webUI version of ArangoDb community Edition.
In their documentation they have given example for writing user defined functions in Arangoshell but not for webUI. Is there a way to write a function in the webUI version?
require("#arangodb/aql/functions").register("MYFUNCTIONS::TEMPERATURE::CELSIUSTOFAHRENHEIT",
function (celsius) {
"use strict";
return celsius * 1.8 + 32;
});
This is NOT the intended usage of user defined functions, the AQL-Documentation clearly states:
These functions are written in JavaScript, and are deployed via an API;
You don't have to use arangosh and the js api client, bindings should provide you with access to the UDF api (e.g. AqlUSerFunction.php of the arangodb-php library).
But if you are so inclined, you can use the knowledge that
Internally, UDFs are stored in a system collection named _aqlfunctions of the selected database. When an AQL statement refers to such a UDF, it is loaded from that collection. The UDFs will be exclusively available for queries in that particular database.
And insert function documents into _aqlfunctions manually.
They are (currently) of the form
{
"name": "MYNAMESPACE::FUNCTIONNAME",
"code": "(function (PARAMS) { return "value"; })",
"isDeterministic": BOOL
}
You can show system collections by clicking on the cog-wheel icon in the upper right and enabling "Type: [X] System".
For library arangodb-spring-data, version 3.2.3, is there any possibility to query for GEO_INTERSECTS functionality using the java api provided by the driver?
Currently I am using an AQL query in my code:
LET areaLiteral = GEO_POLYGON(...)
FOR doc IN MyDocuments
FILTER GEO_INTERSECTS(areaLiteral, doc.geometry)
LIMIT 5 RETURN doc
So far in the official documentation couldn't find anything related to GEO_INTERSECTS, also in this example: https://github.com/arangodb/spring-data-demo#geospatial-queries
I have checked the source code of the driver, but didn't find anything related to keyword "INTERSECTS" which would construct this query behind the scenes.
It is not yet supported, the only supported geospatial queries are Near and Within:
https://www.arangodb.com/docs/3.6/drivers/spring-data-reference-repositories-queries-derived-queries.html#geospatial-queries
I am building a REST API which connects to a NEO4J instance. I am using the koa-neo4j library as the basis (https://github.com/assister-ai/koa-neo4j-starter-kit). I am a beginner at all these technologies but thanks to some help from this forum I have the basic functionality working. For example the below code allows me to create a new node with the label "metric" and set the name and dateAdded propertis.
URL:
/metric?metricName=Test&dateAdded=2/21/2017
index.js
app.defineAPI({
method: 'POST',
route: '/api/v1/imm/metric',
cypherQueryFile: './src/api/v1/imm/metric/createMetric.cyp'
});
createMetric.cyp"
CREATE (n:metric {
name: $metricName,
dateAdded: $dateAdded
})
return ID(n) as id
However, I am struggling to know how I can approach more complicated examples. How can I handle situations when I don't know how many properties will be added when creating a new node beforehand or when I want to create multiple nodes in a single post statement. Ideally I would like to be able to pass something like JSON as part of the POST which would contain all of the nodes, labels and properties that I want to create. Is something like this possible? I tried using the below Cypher query and passing a JSON string in the POST body but it didn't work.
UNWIND $props AS properties
CREATE (n:metric)
SET n = properties
RETURN n
Would I be better off switching tothe Neo4j Rest API instead of the BOLT protocol and the KOA-NEO4J framework. From my research I thought it was better to use BOLT but I want to have a Rest API as the middle layer between my front and back end so I am willing to change over if this will be easier in the longer term.
Thanks for the help!
Your Cypher syntax is bad in a couple of ways.
UNWIND only accepts a collection as its argument, not a string.
SET n = properties is only legal if properties is a map, not a string.
This query should work for creating a single node (assuming that $props is a map containing all the properties you want to store with the newly created node):
CREATE (n:metric $props)
RETURN n
If you want to create multiple nodes, then this query (essentially the same as yours) should work (but only if $prop_collection is a collection of maps):
UNWIND $prop_collection AS props
CREATE (n:metric)
SET n = props
RETURN n
I too have faced difficulties when trying to pass complex types as arguments to neo4j, this has to do with type conversions between js and cypher over bolt and there is not much one could do except for filing an issue in the official neo4j JavaScript driver repo. koa-neo4j uses the official driver under the hood.
One way to go about such scenarios in koa-neo4j is using JavaScript to manipulate the arguments before sending to Cypher:
https://github.com/assister-ai/koa-neo4j#preprocess-lifecycle
Also possible to further manipulate the results of a Cypher query using postProcess lifecycle hook:
https://github.com/assister-ai/koa-neo4j#postprocess-lifecycle
I'm trying to utilize MongoDB 2.4 experimental text search feature from within nodejs. The only problem is, native nodejs mongo drivers don't seem to support collection-level runCommand, as far as I can tell.
The Mongo shell syntax looks like this:
db.collection.runCommand( "text", { search : "Textvalue" } );
There is a db.command / db.executeDbCommand function it appears, but I don't know how to choose a collection and run the text command using it (if it is possible), as it needs to be on the collection level and not the db level.
Any help would be appreciated
I managed to get it working through a combination of Asya Kamsky's comment, by utilizing
this.db.command({text:"collection" , search: "phrase" }).
The problem was it isn't returned like a standard result so a toArray() call was failing. Instead, I put the callback directly inside:
this.db.command({text:"collection" , search: "phrase" }, function(err, cb){
I'm actually working with Zend Framework and I would like to get informations from a ldap directory. For that, I use this code :
$options = array('host' => '...', 'port' => '...', ...);
$ldap = new Zend_Ldap($options);
$query = '(username=' . $_GET['search'] . ')';
$attributes = array('id', 'username', ...);
$searchResults = $ldap->search($query, $ldap->getBaseDn(), Zend_Ldap::SEARCH_SCOPE_SUB, $attributes);
$ldap->disconnect();
There is may be many results so I would like to realize a pagination by limiting the number of results. I searched in the paramters of the search() function of Zend_Ldap which have a sort parameter but nothing to give an interval.
Do you have a solution to limit the number of results (as in sql with limit 0, 200 for example) ?
Thank you
A client-requested size limit can be used to limit the number of entries the directory server will return. The client-requested size limit cannot override any server-imposed size limit, however. The same applies to the time limit. All searches should include a non-zero size limit and time limit. Failure to include size limit and time limit is very bad form. See "LDAP: Programming Practices" and "LDAP: Search Practices" for more information.
"Paging" is accomplished using the simple paged results control extension. described in my blog entry: "LDAP: Simple Paged Results".
Alternatively, a search result listener, should your API support it, could be used to handle results as they arrive which would reduce memory requirements of your application.
Unfortunately, current releases of PHP don't support the ldap pagination functions out of the box - see http://sgehrig.wordpress.com/2009/11/06/reading-paged-ldap-results-with-php-is-a-show-stopper/
If you have control of your server environment, there's a patch you can install with PHP 5.3.2 (and possibly others) that will allow you to do this: https://bugs.php.net/bug.php?id=42060.
.... or you can wait until 5.4.0 is released for production, which should be in the next few weeks, and which include this feature.
ldap_control_paged_results() and ldap_control_paged_results_response() are the functions you'll want to use if you're going with the patch. I think they have been renamed to the singular ldap_control_paged_result() and ldap_control_paged_result_response() in 5.4.
Good luck!