Finding all properties for a schema-less vertex class

Question

I have a class Node extends V. I add instances to Node with some set of document type information provided. I want to query the OrientDB database and return some information from Node; to display this in a formatted way I want a list of all possible field names (in my application, there are currently 115 field names, only one of which is a property used as an index)

To do this in pyorient, the only solution I found so far is (client is the name of the database handle):

count = client.query("SELECT COUNT(*) FROM Node")[0].COUNT
node_records = client.query("SELECT FROM Node LIMIT {0}".format(count))
node_key_list = set([])
for node in node_records:
   node_key_list |= node.oRecordData.keys()

I figured that much out pretty much through trial and error. It isn't very efficient or elegant. Surely there must be a way to have the database return a list of all possible fields for a class or any other document-type object. Is there a simple way to do this through either pyorient or the SQL commands?

Answer 1

I tried your case with this dataset:

And this is the structure of my class TestClass:

As you can see from my structure only name, surname and timeStamp have been created in schema-full mode, instead nameSchemaLess1 and nameSchemaLess1 have been inserted into the DB in schema-less mode.

After having done that, you could create a Javascript function in OrientDB Studio or Console (as explained here) and subsequently you can recall it from pyOrient by using a SQL command.

The following posted function retrieves all the fields names of the class TestClass without duplicates:

Javascript function:

var g = orient.getGraph();

var fieldsList = [];
var query = g.command("sql", "SELECT FROM TestClass");
for (var x = 0; x < query.length; x++){
  var fields = query[x].getRecord().fieldNames();
  for (var y = 0; y < fields.length; y++) {
    if (fieldsList == false){
      fieldsList.push(fields[y]);
    } else {
      var fieldFound = false;
      for (var z = 0; z < fieldsList.length; z++){
        if (fields[y] == fieldsList[z]){
          fieldFound = true;
          break;
        }
      }
      if (fieldFound != true){
        fieldsList.push(fields[y]);
      }
    }
  }
}
return fieldsList;

pyOrient code:

import pyorient


db_name = 'TestDatabaseName'

print("Connecting to the server...")
client = pyorient.OrientDB("localhost", 2424)
session_id = client.connect("root", "root")
print("OK - sessionID: ", session_id, "\n")

if client.db_exists(db_name, pyorient.STORAGE_TYPE_PLOCAL):
    client.db_open(db_name, "root", "root")
    functionCall = client.command("SELECT myFunction() UNWIND myFunction")
    for idx, val in enumerate(functionCall):
        print("Field name:  " + val.myFunction)

client.db_close()

Output:

Connecting to the server...
OK - sessionID:  54 

Field name:  name
Field name:  surname
Field name:  timeStamp
Field name:  out_testClassEdge
Field name:  nameSchemaLess1
Field name:  in_testClassEdge
Field name:  nameSchemaLess2

As you can see all of the fields names, both schema-full and schema-less, have been retrieved.

Hope it helps