Catch/Handle MySQL Duplicate Entry Error - with NodeJS, PassportJS, Express, connect-flash, Heroku
maybe its 3 years late but I'm leaving the answer, better late than never!.
if(err){ //we make sure theres an error (error obj) if(err.errno==1062){ req.flash('message','The entry already exist.'); //we send the flash msg return res.redirect('/admin/userPanel'); db.end(); } else{ throw err; db.end(); }}errorno is the property that you are looking for, I got it when I printed err to console using console.log(err).
Here you can check all the errors number https://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html
it was a pleasure! Good luck to the next good soul that read this.
pretty straight and clear solution://----------------
connection.query('write your mysql query', function(err,rows){ if(err) { if(err.code == 'ER_DUP_ENTRY' || err.errno == 1062) { console.log('Here you can handle duplication') } else{ console.log('Other error in the query') } }else{ console.log('No error in the query') } })