将JSON从Node.js存储到SQL Server

Question

I am extremply new to this kind of development and I am trying to get through this at my best. I am fetching JSON data from my client side, and strying to send these into sql database. I am using SSMS 2012. I get an idea of inserting those values (in the code), but what should I do to store these JSON into SQL database? Is there any way better than I attempted to do? Below are detail information, please let me know if something is unclear.

JSON

{"GradeA":25,"GradeB":36,"GradeC":32}

sql_Table

GradeA | GradeB | GradeC

backend

    app.post('/ping', function (req, res) {
  res.send(res.body);
  var jsondata = JSON.stringify(req.body);
  var test = JSON.parse(jsondata);

  var values = []; 
  values.push(test.GradeA, test.GradeB, test.GradeC)
  console.log(values);

  var dbConn = new sql.Connection(config);

  dbConn.query("INSERT INTO RMS (GradeA, GradeB, GradeC) VALUES ?", [values], function(err, result, fields){
    if (err) throw err;
    //if no error, resulst return as follow
    console.log(result);
    console.log("Number of rows affected :" + result.affectedRows);
    console.log("Number of records affected with warning : " + result.warningCount);
    console.log("Message from MySQL Server : " + result.message);
  });
});

Answer 1

There are several problems with your code.

You are using JSON.stringify instead of JSON.parse :

let json = '{"GradeA":25,"GradeB":36,"GradeC":32}';
let jsondata = JSON.stringify(json);
console.log(typeof jsondata);  // string

let datajson = JSON.parse(json);
console.log(typeof datajson);  // object
console.log(datajson.GradeA);  // 25

Next, it's a really bad idea to make database query in a for loop.

Also note you can't send HTTP response more than once.