cannot read property of undefined with result of mysql

Question

I have this problem, although I managed the value of "result", the conditional expression "if" evaluates "result" always as "! == undefined" I also tried to manage with "result! == ''" but not handles it correctly. In this case I have no results from the sql query because "ricovero.cps" is not in the database and so I wrote some code to handle this case. How should I behave in order for the "if" to work correctly?

function getIdCPS(ricovero){

    console.log("getIdCPS()");
    querySQL = "SELECT id FROM codici_pronto_soccorso WHERE codice ='"+ricovero.cps+"'";
    console.log("querySQL="+querySQL);

    try{

        connection.query(querySQL, function(err, result) {

            if(err)
                console.log(err);

            if( result === undefined){

                return "";
            }else{
                console.log("result is defined");
                console.log("result=("+result+")");
                return result[0].id;
            }
        });

    }catch(e){

        console.log("try/catch error:" + e);

    }

}

Those `return` statements are not going to do anything useful. — Pointy, Aug 21 '19 at 14:50
As a side note, this code is vulnerable to an [SQL injection attack](https://www.owasp.org/index.php/SQL_Injection). — VLAZ, Aug 21 '19 at 14:52
@Jack Bashford I corrected the braces but I still have the same error — , Aug 21 '19 at 14:57

score 0 · Answer 1 · answered Aug 21 '19 at 15:07

0

Just put this code and monitor on console

const getIdCPS = (ricovero) => {
  try {
    const errorObj = { code: 400, error: 'Wrong Input' }
    if (!ricovero || !ricovero.cps) {
      throw errorObj;
    }
    const querySQL = "SELECT id FROM codici_pronto_soccorso WHERE codice ='" + ricovero.cps + "'";
    connection.query(querySQL, (err, result) => {
      if (err) {
        throw err;
      } else if (result) {
        console.log(result);
        return result;
      } else {
        throw err;
      }
    });
  } catch (err) {
    console.error(err);
    throw err;
  }
};

answered Aug 21 '19 at 15:07

Neel Rathod

2,013
12
28

I get the same result, even if result is "undefined" the check expression "if" accepts it as true – Aug 21 '19 at 15:15
can you share your `connection` method, check Is it support `Promise` – Neel Rathod Aug 21 '19 at 15:18
I still haven't implemented the promise but this thing comes in with the check expression? – Aug 21 '19 at 15:21
I don't think so It's come from `if` – Neel Rathod Aug 21 '19 at 15:23
This is all the code: https://pastebin.com/TRSHf2cm Thanks for spend your time with me – Aug 21 '19 at 16:00
@canerandagio I'm at outside... I checked above link where I found you missing curly braces after if statement, Leter on I will check whole code and update you soon – Neel Rathod Aug 21 '19 at 16:17
1

I resolve as follow https://pastebin.com/N42xi6Tw I implemented another if statement for ricovero.cps != "" – Aug 22 '19 at 08:37
Great. It's completely fine – Neel Rathod Aug 22 '19 at 09:36

cannot read property of undefined with result of mysql

1 Answers1