How to extract the result of a query from JSON inside a custom javascript function in OrientDB

Question

I created a custom javascript function in the OrientDB Studio. The function takes a rid as an argument and performs a select query from that rid.

var graph = orient.getGraph();
var res = graph.command( "sql", "select outE('Rel').inV('B').size() as lower_num from " + rid );

So, the result of this query is a number. Depending on the value of this number the function should do different things. I wonder how to extract and use that value from the res variable inside the function. All my attempts have failed so far.. If I return the res variable from the function, the result looks like this:

[
 {
   "@type": "d",
   "@rid": "#-2:1",
   "@version": 0,
   "lower_num": 2
 }
]

So, I tried the following ( res[0]['lower_num'] == 2 ); ( res['lower_num'] == 2 ) and nothing worked.. They always returned false. Any ideas?

Answer 1

OrientDB put ODocument objects in the result set array. So try this:

return res[0].getRecord().field( "lower_num" );

Answer 2

var jsonhelp= [ { "@type": "d", "@rid": "#-2:1", "@version": 0, "lower_num": 2 } ];

var extractedNumber = jsonhelp[0].lower_num;

Now you can compare it with whatever you want; I hope it helps

like this you can extract any of the properties in JSON.

But in javascript there are two types of comparison

1) == simply compares values ,don't consider type
ex. '5' == 5 true , both are 5
     5 == 5 true.
2)=== considers type too
ex. '5' === 5 is false, different type i.e String === integer
     5 === 5 is true ,same type