Convert sql object to valid Json string in node.js - Azure

Question

We are creating a web service in Azure service using node.js to retrieve data from SQL db. We are using ClearDB to do the same.

While retriving the data its not comming in a proper JSON format. How can we convert the result sql object to JSON string.

Below is my code.

app.get('/android', function(request, response) {
    pool.getConnection(function(err, connection) {
        if(err) { handleErrorResponse(err, response); return; }
            var sql = "select projectname from taggedemployee where empname='[email protected]' and tagflag='accepted'"
        connection.query(sql, {}, function(err, results) {
              connection.release(); // always put connection back in pool after last query
          if(err) { handleErrorResponse(err, response); return;  }
                var proj = JSON.stringify(results);
                console.log(proj);
                console.log(proj[0].projectname);
                 for(var myKey in proj) {
                    console.log("key:"+ myKey+", value:"+proj[myKey]);
                 }
          response.setHeader('Content-Type', 'application/json');
          response.status(200).send(JSON.stringify(results) );

        });
    });
});

I cant manipulate the JSON string the returning string is

[{projectname: "Dominos"}]

I tried JSON.stringify but no luck. Please help me to fix this issue

Solution 1

You don't need JSON.stringify() actually. results is already your javascript object, which represents array of json objects. Just use

console.log(results[0].projectname);

Solution 2

The JavaScript Object or Array is JSON, and you need to convert a JSON string to a JavaScript Object thru the function eval or JSON.parse. Please refer to http://www.json.org/js.html.

Solution 3

The response from the SQL service is JSON - as you have shown. You need to use JSON.parse() to parse the JSON into an object. Something like:

app.get('/android', function(request, response) {
    pool.getConnection(function(err, connection) {
        if(err) { handleErrorResponse(err, response); return; }
            var sql = "select projectname from taggedemployee where empname='[email protected]' and tagflag='accepted'"
        connection.query(sql, {}, function(err, results) {
              connection.release(); // always put connection back in pool after last query
          if(err) { handleErrorResponse(err, response); return;  }
                var proj = JSON.parse(response);
                console.log(proj);
          response.setHeader('Content-Type', 'application/json');
          response.status(200).send(results);

        });
    });
});

JSON.stringify is used to convert an object into a JSON string. JSON.parse is used to convert a JSON string into an object.