node.js mysql push callback

Question

   mysql.query('SELECT accountID,deviceID FROM EventData WHERE accountID = "'
       + acc
       + '" AND deviceID = "'
       + deviceID
       + '"  ORDER BY timestamp DESC LIMIT 1 ',
           function(err,rows,fields) {                   
               if (rows.length > 0) {                 
                   var accountID = rows[0].accountID;
                   var deviceID = rows[0].deviceID;
                   var re2 = ({
                       title: deviceID,                    
                   });                      
                   console.log(re2)
                   console.log("aaa")     
           }
    );

The above code produces the following output :

   [{ title: 'dev1'}]
   aaa
   [{ title: 'dev2'}]
   aaa

But I expected to see the following:

   [{ title: 'dev1'},
   { title: 'dev2'}]
   aaa

What am I doing wrong?

First off, please do not concatenate SQL query strings like that, use the placeholder syntax as it is more secure. Secondly, the code you've currently shown cannot produce the output you've shown, especially since re2 is not an array, it's an object. — mscdex
– mscdex, Commented Nov 8, 2014 at 14:51

idoshamun · Accepted Answer · 2014-11-08 15:44:08Z

1

You didn't even iterate through the rows, you just added the first title to re2.

This code should work:

mysql.query('SELECT accountID,deviceID FROM EventData WHERE accountID = ? AND deviceID = ? ORDER BY timestamp DESC LIMIT 1', [acc, deviceID],
       function(err,rows,fields) {
           if (rows.length > 0) { 
               var re2 = [ ];                    
               for (var i = 0; i < rows.length; i++) {
                   re2.push({ title: rows[i].deviceID });
               }                    
               console.log(re2);
               console.log("aaa")  ;
           }   
       }
);

Please note that I passed the parameters with placeholders instead of concatenate them explicitly to the string.

answered Nov 8, 2014 at 15:44

idoshamun

1,1359 silver badges22 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

node.js mysql push callback

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related