CODEWITHSUNDEEP
node.jslockingsails.jswaterline
user1345112
user1345112

Reputation: 342

nodejs - sails.js lock query (transactions)

The case:

I'm creating an api with SAILS.js, sails.js uses waterline for ORM. The api returns lets say photographs, many users are able to vote for a picture. The pictures will be ordered on number of votes.

Procedure: When a user votes for a song, I've to check the number of votes ("SELECT"|| picture.findById()) AND after that I have to increment that number by one ("UPDATE" picture.update).

Problem: transaction/ locking in Sails.js, these two queries should be excecuted without having a other query modifying the picture data within the select and update query of our vote system.

How should we perform locking/ transition in sails.js (node js framework)

THANKS

Upvotes: 5

Views: 856

Answers (1)

Timofey Biryukov
Timofey Biryukov

Reputation: 376

Sails does support transactions.

Here is an example of a transaction in sails.js:

await sails.getDatastore().transaction(async db=> {

  await Model
    .create({foo: bar})
    .usingConnection(db);

  if (somethingWentWrong) {
    throw 'error happened - transaction rollback';
  }

  await Model
    .update({id: 1}))
    .set({votes: 1})
    .usingConnection(db);

}).intercept('Error', () => res.serverError());

Upvotes: 0

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