How to Export to csv file?

[stevenluoxiaohua]

`p.stream('select * from users')

.pipe(etl.stringify(0,null,true))
.pipe(etl.toFile('txt/test.txt'))
.promise()
.then(function() {
console.log('done')
})
.catch(function(e) {
console.log('error',e);
});`

I'm try like this, but how to do next?

[ZJONSSON]

A very simple example would be something like:

// assuming mysql client for the select
client.query('select * from users').stream()
  .pipe(etl.map(function(d) {
    // if we haven't sent headers, we start by doing so
    if (!this.headers)
      this.headers = this.push('"'+Object.keys(d).join('","')+'"\n') || true;
    return '"'+Object.keys(d).map(key => d[key]).join('","')+'"\n';
  })
  .pipe(etl.toFile('txt/text.txt'))
  .promise()
  .then(...)

However this does not properly escape the fields. A safer bet would be to use something like csv-write-stream which I believe you can use like this:

var csvWriter = require('csv-write-stream');

client.query('select * from users').stream()
  .pipe(csvWriter())
  .pipe(etl.toFile('txt/text.txt'))
  .promise()
  .then(...)

Let me know if this works or not for you

[stevenluoxiaohua]

thanks,
It works ok, code as follows

`var pool = mysql.createPool({
host: 'localhost',
port: '3306',

database: 'gss'

});

var p = etl.mysql.execute(pool);

p.stream('select * from test')
.pipe(csvWriter({
separator: ',',
newline: '\n',
headers: undefined,
sendHeaders: false
}))
.pipe(etl.toFile('txt/text.txt'))
.promise()
.then(function () {
console.log('done')
});`

now, I try insert to database using mysql

[ZJONSSON]

see #31 for the other question