Import from Parse

Parse is a very popular BaaS (Backend as a Service), acquired by Facebook. Parse uses MongoDB as database and allows to export the database in JSON format. The format is an array of JSON object. Example:

[
    {
        "user": {
            "__type": "Pointer",
            "className": "_User",
            "objectId": "Ldlskf4mfS"
        },
        "address": {
            "__type": "Pointer",
            "className": "Address",
            "objectId": "lvkDfj4dmS"
        },
        "createdAt": "2013-11-15T18:15:59.336Z",
        "updatedAt": "2014-02-27T23:47:00.440Z",
        "objectId": "Ldk39fDkcj",
        "ACL": {
            "Lfo33mfDkf": {
                "write": true
            },
            "*": {
                "read": true
            }
        }
    }, {
        "user": {
            "__type": "Pointer",
            "className": "_User",
            "objectId": "Lflfem3mFe"
        },
        "address": {
            "__type": "Pointer",
            "className": "Address",
            "objectId": "Ldldjfj3dd"
        },
        "createdAt": "2014-01-01T18:04:02.321Z",
        "updatedAt": "2014-01-23T20:12:23.948Z",
        "objectId": "fkfj49fjFFN",
        "ACL": {
            "dlfnDJckss": {
                "write": true
            },
            "*": {
                "read": true
            }
        }
    }
]

Notes:

• Each object has own objectId that identifies the object in the entire database.
• Parse has the concept of class, like OrientDB
• Links are similar to OrientDB RID (but it requires a costly JOIN to be traversed), but made if an embedded object containing:
  • className as target class name
  • objectIf as target objectId
• Parse has ACL at record level, like OrientDB.

In order to import a PARSE file, you need to create the ETL configuration using JSON as Extractor.

Example

In this example we're going to import the file extracted from Parse containing all the records of user class. Note the creation of class User in OrientDB that extends V (Base Vertex class). We created an index against property User.objectId to use the same ID as for Parse. If you execute this ETL importing multiple time, the record in OrientDB will be updated thanks to the merge.

{
  "config": {
    "log": "debug"
  },
  "source" : {
    "file": { "path": "/temp/parse-user.json", "lock" : true }
  },
  "extractor" : {
    "json": {}
  },
  "transformers" : [
   { "merge": { "joinFieldName":"objectId", "lookup":"User.objectId" } },
   { "vertex": { "class": "User"} }
  ],
  "loader" : {
    "orientdb": {
      "dbURL": "plocal:/temp/databases/parse",
      "dbUser": "admin",
      "dbPassword": "admin",
      "dbAutoCreate": true,
      "tx": false,
      "batchCommit": 1000,
      "dbType": "graph",
      "classes": [
        {"name": "User", "extends": "V"}
      ],      
      "indexes": [
        {"class":"User", "fields":["objectId:string"], "type":"UNIQUE_HASH_INDEX" }
      ]
    }
  }
}

Look also at - Import from JSON.