Using Streams in MySQL with Node

Question

Following the example on Piping results with Streams2, I'm trying to stream results from MySQL to stdout in node.js.

Code looks like this:

connection.query('SELECT * FROM table')
      .stream()
      .pipe(process.stdout);

I get this error: TypeError: invalid data

Answer 1

Explanation

From this github issue for the project:

.stream() returns stream in "objectMode". You can't pipe it to stdout or network socket because "data" events have rows as payload, not Buffer chunks

Fix

You can fix this using the csv-stringify module.

var stringify = require('csv-stringify');

var stringifier = stringify();


connection.query('SELECT * FROM table')
    .stream()
    .pipe(stringifier).pipe(process.stdout);

notice the extra .pipe(stringifier) before the .pipe(process.stdout)