Example of importing data with cloud functions. See a live example at https://www.back4app.com/database/davimacedo/parse-import-example

curl.sh

curl -X POST \
-H "X-Parse-Application-Id: LL9oIdzIkmwl5xyowQQu0fTmXyUWfet9RuAzwHfj" \
-H "X-Parse-REST-API-Key: R3S8PYQKuzeV4c8MUeO5ved46C50MEp56boDHW1O" \
-H "Content-Type: application/json" \
-d @data.json \
https://parseapi.back4app.com/functions/import

data.json

{
	"className": "ExampleClass",
	"rows": [
		{ "ExampleColumnA": "row1columnA", "ExampleColumnB": "row1columnB" },
		{ "ExampleColumnA": "row2columnA", "ExampleColumnB": "row2columnB"}
	]
}

main.js

Parse.Cloud.define('import', async request => {
  const className = request.params.className;
  const rows = request.params.rows;

  const MyClass = Parse.Object.extend(className);

  var myClassObjects = [];
  for (let i = 0; i < rows.length; i++) {
    const myClassObject = new MyClass();

    for (const column in rows[i]) {
      myClassObject.set(column, rows[i][column]);
    }

    myClassObjects.push(myClassObject);
  }

  try {
    await Parse.Object.saveAll(myClassObjects);
  } catch (e) {
    throw new Error(`Import failed: ${e}`);
  }
  
  return `Successfully imported ${myClassObjects.length} rows into ${className} class`;
});

I keep getting this error - {"code":141,"error":"Import failed: undefined"} after trying to import through curl.

nevermind, i just wasn't using my master key. It works great.

Actually I tried importing a 1mb file of about 10,000 rows and the connection reset. It worked for much smaller amounts though. What is the size limit for imports through this method?

There is no specific limit, but 10,000 would reach your api 10,000 times. You would have to modify little bit the code to make it upload something like 1000 each minute.

@mpc20001 keep getting the same error, while using the master key
promises.push(myClassObject.save({useMasterKey:true}));

I have client class creation set, even trying on small file..... not sure what is blocking

Log files say
Fri Jan 06 2017 12:31:53 GMT+0000 (UTC) Error: Can't set headers after they are sent. at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:344:11) at ServerResponse.header (/usr/src/app/node_modules/express/lib/response.js:719:10) at ServerResponse.send (/usr/src/app/node_modules/express/lib/response.js:164:12) at ServerResponse.json (/usr/src/app/node_modules/express/lib/response.js:250:15) at /usr/src/app/src/back/app.js:104:9 at Layer.handle_error (/usr/src/app/node_modules/express/lib/router/layer.js:71:5) at trim_prefix (/usr/src/app/node_modules/express/lib/router/index.js:310:13) at /usr/src/app/node_modules/express/lib/router/index.js:280:7 at Function.process_params (/usr/src/app/node_modules/express/lib/router/index.js:330:12) at next (/usr/src/app/node_modules/express/lib/router/index.js:271:10) at Layer.handle_error (/usr/src/app/node_modules/express/lib/router/layer.js:67:12) at trim_prefix (/usr/src/app/node_modules/express/lib/router/index.js:310:13) at /usr/src/app/node_modules/express/lib/router/index.js:280:7 at Function.process_params (/usr/src/app/node_modules/express/lib/router/index.js:330:12) at next (/usr/src/app/node_modules/express/lib/router/index.js:271:10) at Immediate.<anonymous> (/usr/src/app/node_modules/express/lib/application.js:232:9)

Seems there is a problem with the promise fulfilment. I changed the code for
Parse.Object.saveAll(myObjectArray).
Unfortunately, the code can save the entries as new objects, but can not migrate data... in other words, attempts to set the object ID results in
{"code":141,"error":"Import failed: Object not found."}

Any ideas?

This does not work, I get "unexpected token /" or c or t

I can't get any of this to work either..
I put main.js in my Parse sever directoy and called http://localhost:1337/parse/main.js "returns :error, unouthorize"

hi Davi, this works great, you save my day. @nyxee im tested on localhost and works. your url change to http://localhost:1337/parse/function/{name}

Glad to know!

Is there a better way of importing data to parse server?
Imagine thousand of rows to import, I'm worried about those for loops there.

@Milad-abbasi I've just updated the example to be compliant with the latest version of Parse and also to use Parse.Object.saveAll(). It conveniently splits the requests in batches so you can make sure it works properly. I also added the link for a living example at the Back4App Database Hub so you can just run and see the imported rows or clone, check the cloud code out and play around.

Little heads up for anyone looking. I feel like there could be a small versioning issue between the function here and the one posted in the live example. The version on this page revised on Jan 5 2020 and current as of June 23 2021 works great for me and also employs the improvements the owner describes in his Jan 5 2020 comment. Whereas the example posted in the live example fails for me at the line Parse.Promise.when(promises).

Thanks for the heads up. I've just updated the live example code.