Support for streams

[wcoppens]

Just checking out this awesome library and found out that the query method always returns a promise. Does this mean the original node-postgres callback and stream functions of the query method won't work properly with this library?

So far i haven't been able to get both of these working properly, but it might be possible that i am missing something?

Thanks!

[MatteoGioioso]

Hello, unfortunately I have never used streams with node-postgres. I suppose that something like this won't work then?

const QueryStream = require('pg-query-stream')
const JSONStream = require('JSONStream')

const ServerlessClient = require('serverless-postgres')

const client = new ServerlessClient({
    user: process.env.DB_USER,
    host: process.env.DB_HOST,
    database: process.env.DB_NAME,
    password: process.env.DB_PASSWORD,
    port: process.env.DB_PORT,
    debug: true,
    delayMs: 3000,
});

const handler = async(event, context) => {
    await client.connect();

    const query = new QueryStream('SELECT * FROM generate_series(0, $1) num', [1000000])
    const stream = await client.query(query);

    stream.pipe(JSONStream.stringify()).pipe(process.stdout)

    await client.clean();

   ...
}

[MatteoGioioso]

I have managed to "get it working":

  describe.only("streams", function() {
    it("should work with streams", async function(done) {
      const QueryStream = require('pg-query-stream')
      const JSONStream = require('JSONStream')
      const query = new QueryStream('SELECT * FROM generate_series(0, $1) num', [100000])
      const client = new ServerlessClient({
        ...dbConfig,
        debug: true,
      });

      await client.connect();
      const stream = await client.query(query);
      stream.pipe(JSONStream.stringify()).pipe(process.stdout)
      stream.on('end', async function() {
        console.log("END");
        await client.end();
        done()
      })
    });
  })

Keep in mind that is long time that I did not work with node, I might have used some bad async pattern