MySQL 5.6.41 errno 1064: Creating a MySQL query with variables - mysql

Question

I have a (currently localhost, but soon to be through AWS) Node.JS server with Express and I'm trying to update an RDS instance through a MySQL query when I'm getting the following error:
{ [Error: ER_PARSE_ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''history0' = 'http://localhost:3000/' WHERE id = 1' at line 1]
code: 'ER_PARSE_ERROR',
errno: 1064,
sqlMessage: 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'\'history0\' = \'http://localhost:3000/\' WHERE id = 1\' at line 1',
sqlState: '42000',
index: 0,
sql: 'UPDATE infected SET \'history0\' = \'http://localhost:3000/\' WHERE id = 1;' }
The POST request causing the error:
app.post('/history', function(req, res) {
var hist = 'history' + 0;
var sql = 'UPDATE infected SET ? = ? WHERE id = ?;';
connection.query(sql, [hist, req.body[0].url, 1]);
});
I'm using hist as a variable because I plan to have it in a loop, but I wasn't sure if the way I'm declaring it here is causing the issue so I left it as is. req.body is the output of JSON.stringify() called on call to chrome.history.search(). So I'm trying to get the URL of the entry at index 0.
I've tried a direct call to connection.query with a hard-coded string as follows:
connection.query("UPDATE infected SET history0='google.com' WHERE id='1'");
and it successfully updates the database, so I figure there's an issue with how I'm using the question marks to insert variables hist and req.body[0].url into the query, but I can't figure out what the issue is.

Answer 1

try with double "??" for the keys, this way:
app.post('/history', function(req, res) {
var hist = 'history' + 0;
var sql = 'UPDATE infected SET ?? = ? WHERE id = ?;';
connection.query(sql, [hist, req.body[0].url, 1]);
});