While streaming data, pausing the stream results in "TypeError: request.pause is not a function"

I want to stream 1 million+ rows from mssql database to another database. To deal with the Backpressure (mssql database is way faster) I want to pause the stream until the data at hand is processed (and prevent Memory exhaustion).

However when using the example from this repository I keep running into this error: "TypeError: request.pause is not a function"

Code snippet

const sql = require('mssql');

const config = {
  user: 'user-name',
  password: 'password',
  server: 'hostname,
  database: 'databasename',
  options: {
      encrypt: true // Use this if you're on Windows Azure
  }
}

sql.connect(config, err => {
  if (err) {
    // @todo log error
  }
  else{
    var rowsToProcess = [];
    var request = new sql.Request();
    request.stream = true;
    request.query('select * from table_name')

    request.on('row', row => {
      rowsToProcess.push(row);
      if (rowsToProcess.length > 100) {
        request.pause();
        processRows();
      }
    });

    request.on('done', () => {
      processRows();
      sql.close();
    })

    function processRows() {
      rowsToProcess = [];
      request.resume();
    }
  }
});

Running code snippet results in following error:

TypeError: request.pause is not a function
    at Request.request.on.row (/Users/folder/test.js:26:17)
    at Request.emit (events.js:182:13)
    at Request.req.on.columns (/Users/folder/node_modules/mssql/lib/tedious.js:780:20)
    at Request.emit (events.js:182:13)
    at Parser.<anonymous> (/Users/folder/node_modules/mssql/node_modules/tedious/lib/connection.js:744:28)
    at Parser.emit (events.js:182:13)
    at Parser.<anonymous> (/Users/folder/node_modules/mssql/node_modules/tedious/lib/token/token-stream-parser.js:54:15)
    at Parser.emit (events.js:182:13)
    at addChunk (/Users/folder/node_modules/readable-stream/lib/_stream_readable.js:291:12)
    at readableAddChunk (/Users/folder/node_modules/readable-stream/lib/_stream_readable.js:278:11)

Software versions

• NodeJS: v10.15.0
• node-mssql: mssql": “^4.3.1”
• SQL Server: (azure)

Does anyone have a clue?

[charutiwari04]

Thank you @dhensby As suggested, temporarily it has been fixed. Opened tedious issue for this.

[dhensby]

as a temp fix I assume you can pass through your own textsize property in your connection config

Also, that is from the tedious lib so you’ll have to raise it there

---

https://github.com/tediousjs/tedious/blob/v6.0.0/src/connection.js#L42 - this is where it’s set