Reputation: 155
I'm trying to parse file with data and insert it in the database, parsing goes well and when I make one query it runs great to, but when I trying to get this queries work in cycle it give me
values: [output[i][0], output[i][1], output[i][2], output[i][3], o
^
TypeError: Cannot read property '0' of undefined
First I was trying simple for loop but after some research about nodeJS being async I find that i need to do this in callback, but it didn't works, I think that parsing is not done by moment of starting queries routine, but I'm not sure.
var express = require('express');
var pg = require('pg');
var csv = require('fast-csv');
var app = express();
var conString = "postgres://alexzander:,tjdekma@localhost/db2015";
var output = [];
var client = new pg.Client(conString);
parser = csv.fromPath("public/dataInputOld/tblOwner.txt", {delimiter: ';'});
parser.on("data", function (data) {
output.push(data);
});
parser.on("end", query(1));
function query(i) {
if (i < 30) {
client.query({
text: 'INSERT INTO tblowner ' +
'(intownerid, txtownersurname, txtownername, txtownersecondname, txtaddress)' +
' VALUES ($1, $2, $3, $4, $5)',
values: [output[i][0], output[i][1], output[i][2], output[i][3], output[i][4]]
}, function (err) {
if (err) {
console.log('error: ' + err)
}
else {
console.log(i);
query(i + 1);
}
});
}
}
app.get('/', function (req, res) {
res.send(JSON.stringify(output[1][0]));
});
var server = app.listen(3001, function () {
var host = server.address().address;
var port = server.address().port;
console.log('App listening at http://%s:%s', host, port);
});
Update: now I think that i didn't connect well to database
Update2: I changed
parser.on("end", query(1));
to
parser.on("end", function(){
query(1);
});
and now error is gone, but nothing inserts in database
Upvotes: 1
Views: 195
Reputation: 155
Ended with this, sorry but I didn't understand enough about pg and getting client in it, so when i did all like in example on there docs all worked fine, thanks stackoverflow :) If I didn't try to explain this trouble to you I think I might be searching for errors a lot more time.
parser.on("end", function () {
client.connect(function(err){
if (err) {
return console.error('could not connect to postgres', err);
}
query(1);
});
});
function query(i) {
if (i < 30) {
client.query({
text: 'INSERT INTO tblowner ' +
'(intownerid, txtownersurname, txtownername, txtownersecondname, txtaddress)' +
' VALUES ($1, $2, $3, $4, $5)',
values: [output[i][0], output[i][1], output[i][2], output[i][3], output[i][4]]
}, function (err) {
if (err) {
console.log('error: ' + err)
}
else {
console.log(i);
query(i + 1);
}
});
}else{
client.end();
}
}
Upvotes: 1