Like most io in node, tedious responds asynchronously. However you are
treating your connect_db function as if it operated synchronously. The
result array will still be empty when the function returns.
Pushing stuff in to the result array in the 'row' event is fine; that will
allow you to accumulate the data.
You possibly only want to do
res.write(results);
res.end("hello world");
in the Request's callback function (which is called once the request is
complete).
So something along these lines.
if (err) {
...
} else {
res.write(results);
res.end("hello world");
}
Of course you'll need to pass res to your connect_db function.
Or you could write each result in the 'row' event handler, then
res.end("hello world");
in the Request's completion function.
On Friday, 22 March 2013 17:06:23 UTC, Ibrahim Gaal wrote:
>
> Hi Guys,
>
> I'm also very new to node, and would appreciate any help you can provide.
> I have a http webserver created in node js. once you hit the server I'd
> like it respond with some json data.
> I'm able to connect to my sql server database using the tedious module. I
> can extract data from my tables and write to console, however I'm having
> problems returning the data back as the http web server's response.
>
> please see code below
>
> var http = require('http');
> var s = http.createServer(function (req, res) {
> res.writeHead(200, {'Content-Type': 'text/plain'});
>
> var results = connect_db();
> res.write(results);
> res.end("hello world");
>
>
> });
> s.listen(9090);
>
>
> function connect_db(){
>
> // Global variables
> var Connection = require('tedious').Connection;
> var Request = require('tedious').Request;
> var TYPES = require('tedious').TYPES;
>
> var result = [];
> var config = {
> userName: 'user1',
> password: 'password',
> server: 'localhost',
> "options": {
> "database": "testdb",
> }
> };
>
> // create connection instance/object
> var connection = new Connection(config);
>
> connection.on('connect', function(err){
>
> if (err){
> console.log(err);
> console.log('Unable to connect to database');
> }
> else {
> console.log('connection to database established');
> }
>
> // create Request instance
> request = new Request("select top 1 id from table1", function(err,
> rowCount) {
> // error check request
> if (err) {
> console.log(err);
> console.log('request error');
> }
>
> // close connection after rows return for request
> if (rowCount)
> {
> console.log('finished');
> connection.close();
> console.log('db connection closed');
> }
>
> });
>
>
> request.on('row', function(columns) {
> columns.forEach(function(column) {
> //console.log(column.value);
> results.push(column.value);
> //console.log(foo);
>
> });
> });
>
> connection.execSql(request);
>
> });
>
>
> return result;
> }
>
>
>
> On Wednesday, January 9, 2013 7:37:13 AM UTC, Bhoomi Kakaiya wrote:
>>
>>
>> Hi all,
>>
>> I am pretty new to Node. I am using Tediuos to get data from SQL
>> database.
>>
>> Here is the code snippet :
>>
>> app.get('/getitems', function(req, res){
>> res.contentType('application/json');
>> var config = { userName: 'sa', password: 'pass', server:
>> '127.0.0.1', options : { database:'Auto'}
>> };
>> var connection = new Connection(config);
>> connection.on('connect', function(err) {
>> executeStatement(res);
>> });
>> function executeStatement(res1) {
>> console.log(res1.contentType);
>> request = new Request("select top 3 sItemId [Id], sName [Item], nrate1
>> [Rate] from bmitem", function(err, rowCount) {
>> if (err) {
>> console.log(err);
>> } else {
>> console.log(rowCount + ' rows');
>> }
>> connection.close();
>> });
>>
>> request.on('row', function(columns) {
>> columns.forEach(function(column) {
>> if (column.value === null) {
>> console.log('NULL');
>> } else {
>> console.log(column.value);
>> }
>> });
>> });
>> request.on('done', function(rowCount, more) {
>> console.log(rowCount + ' rows returned');
>> debugger;
>> res1.send("3");// Here is the problem. Debugger shows res1 is <error>.
>> });
>> connection.execSql(request);
>> }
>> });
>>
>>
>> The problem is response object has error.
>> I want to create json of the items returned from db and want to pass it
>> as json in the ajax request.
>>
>> If I return response in request.on("row") it works. Do not understand why
>> response object is not available on "done" event.
>>
>> Thanks in advance.
>>
>> Bhoomi.
>>
>>
>>
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