-
Notifications
You must be signed in to change notification settings - Fork 0
/
index.js
81 lines (75 loc) · 2.33 KB
/
index.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
var express = require('express');
var mysql = require('mysql');
var Promise = require('bluebird');
var bodyParser = require('body-parser');
var app = express();
var connection = mysql.createConnection({
host : 'localhost',
user : 'root',
password : '',
database : 'my_db'
});
var queryAsync = Promise.promisify(connection.query.bind(connection));
connection.connect();
// do something when app is closing
// see http://stackoverflow.com/questions/14031763/doing-a-cleanup-action-just-before-node-js-exits
process.stdin.resume()
process.on('exit', exitHandler.bind(null, { shutdownDb: true } ));
var bodyParser = require('body-parser');
app.use(bodyParser.urlencoded({ extended: true }));
app.get('/', function (req, res) {
var numRows;
var queryPagination;
var numPerPage = parseInt(req.query.npp, 10) || 1;
var page = parseInt(req.query.page, 10) || 0;
var numPages;
var skip = page * numPerPage;
console.log(req.query);
console.log(page)
console.log(numPerPage);
console.log(skip);
// Here we compute the LIMIT parameter for MySQL query
var end_limit = numPerPage;
var limit = skip + ',' + end_limit;
console.log(limit);
console.log("SELECT * FROM stocks DESC LIMIT " + limit);
queryAsync('SELECT count(*) as numRows FROM stocks')
.then(function(results) {
numRows = results[0].numRows;
numPages = Math.ceil(numRows / numPerPage);
console.log('number of pages:', numPages);
})
.then(() => queryAsync('SELECT * FROM stocks DESC LIMIT ' + limit))
.then(function(results) {
var responsePayload = {
results: results
};
if (page < numPages) {
responsePayload.pagination = {
current: page,
perPage: numPerPage,
previous: page > 0 ? page - 1 : undefined,
next: page < numPages - 1 ? page + 1 : undefined
}
}
else responsePayload.pagination = {
err: 'queried page ' + page + ' is >= to maximum page number ' + numPages
}
res.json(responsePayload);
})
.catch(function(err) {
console.error(err);
res.json({ err: err });
});
});
app.listen(3000, function () {
console.log('Example app listening on port 3000!');
});
function exitHandler(options, err) {
if (options.shutdownDb) {
console.log('shutdown mysql connection');
connection.end();
}
if (err) console.log(err.stack);
if (options.exit) process.exit();
}