I use the following code using mysql with Node.js
var mysql = require('mysql');
var db = mysql.createConnection({host:'localhost', user:'root', password: 'pw', database: 'db'});
db.connect();
And, I use this to SELECT data and handle error.
db.query("SELECT * FROM user_info WHERE uid = ? LIMIT 1", [selfid], function(err, rows, fields) {
if (err) throw err;
// do something....
});
But, I want to ask that when I use "INSERT" and some error happens, will the app.js crash if I haven't handle error?
var qstr = "INSERT INTO user_info (uid, message, created_time) VALUES(?, ?, CURRENT_TIMESTAMP)";
db.query(qstr, [uid, message]);
No, the app will not crash if you do not handle your errors. It will continue silently. It is up to you to catch the errors and handle them.
var qstr = "INSERT INTO user_info syntax error";
db.query(qstr, function(err) {
if (err) {
console.log("A wild error appeared!", err);
process.exit(1);
}
});
Related
I'm using nodejs 10.26 + express 3.5 + node-mysql 2.1.1 +
MySQL-Server Version: 5.6.16.
I got 4 DELETE's and want only 1 Database Request, so i connected the DELETE commands with a ";"... but it fails always.
var sql_string = "DELETE FROM user_tables WHERE name = 'Testbase';";
sql_string += "DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase';";
sql_string += "DELETE FROM user_tables_rules WHERE parent_table_name = 'Testbase';";
sql_string += "DELETE FROM user_tables_columns WHERE parent_table_name = 'Testbase';";
connection.query(sql_string, function(err, rows, fields) {
if (err) throw err;
res.send('true');
});
It throws this 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 'DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase';DELETE FR' at line 1
But if i paste this SQL in PhpMyAdmin it is always successful...
If i write it in single query's its succeed, too.
connection.query("DELETE FROM user_tables WHERE name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_rules WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_columns WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
res.send('true');
});
});
});
});
Thanks for help!
I guess you are using node-mysql. (but should also work for node-mysql2)
The docs says:
Support for multiple statements is disabled for security reasons (it
allows for SQL injection attacks if values are not properly escaped).
Multiple statement queries
To use this feature you have to enable it for your connection:
var connection = mysql.createConnection({multipleStatements: true});
Once enabled, you can execute queries with multiple statements by separating each statement with a semi-colon ;. Result will be an array for each statement.
Example
connection.query('SELECT ?; SELECT ?', [1, 2], function(err, results) {
if (err) throw err;
// `results` is an array with one element for every statement in the query:
console.log(results[0]); // [{1: 1}]
console.log(results[1]); // [{2: 2}]
});
So if you have enabled the multipleStatements, your first code should work.
Using "multiplestatements: true" like shown below worked for me
var connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '',
database: '',
multipleStatements: true
});
connection.connect();
var sql = "CREATE TABLE test(id INT DEFAULT 1, name VARCHAR(50));ALTER TABLE test ADD age VARCHAR(10);";
connection.query(sql, function(error, results, fields) {
if (error) {
throw error;
}
});
To Fetch Data from DB(SQL), the following function would work accurately
router.get('/', function messageFunction(req, res){
//res.send('Hi Dear Rasikh, Welcome to Test Page.') //=> One Way
dbConn.query('SELECT COUNT(name) as counted, name, last_name, phone, email from students',
function (err, rows, fields) { // another Way
if (err) throw err
dbConn.query('SELECT name, author from books',
function (err, rowsBook, fields) { // another Way
if (err) throw err
// console.log('The counted is: ', rows[0].counted); //=> Display in console
// res.send('Hi Dear Rasikh, Welcome to Test Page.'+ rows[0].counted) //=> Display in blank page
res.render('main/index',{data:rows, myData:rowsBook});
})
});
});
I'm using nodejs 10.26 + express 3.5 + node-mysql 2.1.1 +
MySQL-Server Version: 5.6.16.
I got 4 DELETE's and want only 1 Database Request, so i connected the DELETE commands with a ";"... but it fails always.
var sql_string = "DELETE FROM user_tables WHERE name = 'Testbase';";
sql_string += "DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase';";
sql_string += "DELETE FROM user_tables_rules WHERE parent_table_name = 'Testbase';";
sql_string += "DELETE FROM user_tables_columns WHERE parent_table_name = 'Testbase';";
connection.query(sql_string, function(err, rows, fields) {
if (err) throw err;
res.send('true');
});
It throws this 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 'DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase';DELETE FR' at line 1
But if i paste this SQL in PhpMyAdmin it is always successful...
If i write it in single query's its succeed, too.
connection.query("DELETE FROM user_tables WHERE name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_rules WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_columns WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
res.send('true');
});
});
});
});
Thanks for help!
I guess you are using node-mysql. (but should also work for node-mysql2)
The docs says:
Support for multiple statements is disabled for security reasons (it
allows for SQL injection attacks if values are not properly escaped).
Multiple statement queries
To use this feature you have to enable it for your connection:
var connection = mysql.createConnection({multipleStatements: true});
Once enabled, you can execute queries with multiple statements by separating each statement with a semi-colon ;. Result will be an array for each statement.
Example
connection.query('SELECT ?; SELECT ?', [1, 2], function(err, results) {
if (err) throw err;
// `results` is an array with one element for every statement in the query:
console.log(results[0]); // [{1: 1}]
console.log(results[1]); // [{2: 2}]
});
So if you have enabled the multipleStatements, your first code should work.
Using "multiplestatements: true" like shown below worked for me
var connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '',
database: '',
multipleStatements: true
});
connection.connect();
var sql = "CREATE TABLE test(id INT DEFAULT 1, name VARCHAR(50));ALTER TABLE test ADD age VARCHAR(10);";
connection.query(sql, function(error, results, fields) {
if (error) {
throw error;
}
});
To Fetch Data from DB(SQL), the following function would work accurately
router.get('/', function messageFunction(req, res){
//res.send('Hi Dear Rasikh, Welcome to Test Page.') //=> One Way
dbConn.query('SELECT COUNT(name) as counted, name, last_name, phone, email from students',
function (err, rows, fields) { // another Way
if (err) throw err
dbConn.query('SELECT name, author from books',
function (err, rowsBook, fields) { // another Way
if (err) throw err
// console.log('The counted is: ', rows[0].counted); //=> Display in console
// res.send('Hi Dear Rasikh, Welcome to Test Page.'+ rows[0].counted) //=> Display in blank page
res.render('main/index',{data:rows, myData:rowsBook});
})
});
});
throw err; // Rethrow non-MySQL errors
^
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 ''a', 'b', 'c'' at line 1
(I had entered a as the name,b as the username and c as the password in the form)
I can't figure out where the problem is.
db.js:
function createUser(name, username, password){
var sql = "INSERT INTO users (name,username,password) VALUES ?";
var values = [name, username, password];
con.query(sql, [values], function (err, result) {
if (err) throw err;
console.log('inserted');
});
}
module.exports = {createUser};
relevant part of server.js:
app.post('/create', function(req,res) {
db.createUser(req.body.name,req.body.username,req.body.password);
res.status(200).send();
});
I think you just need additional square brackets around the values:
var sql = "INSERT INTO users (name,username,password) VALUES ?";
var values = [[name, username, password]];
con.query(sql, [values], function (err, result) { ... });
This mechanism is mostly meant to insert multiple rows. You could also separate the parameters:
var sql = "INSERT INTO users (name,username,password) VALUES (?, ?, ?)";
var values = [name, username, password];
con.query(sql, values, function (err, result) { ... });
You have to add for every variable a placeholder
function createUser(name, username, password){
var sql = "INSERT INTO users (name,username,password) VALUES (?,?,?);";
var values = [name, username, password];
con.query(sql, values, function (err, result) {
if (err) throw err;
console.log('inserted');
});
}
module.exports = {createUser};
I'm using nodejs 10.26 + express 3.5 + node-mysql 2.1.1 +
MySQL-Server Version: 5.6.16.
I got 4 DELETE's and want only 1 Database Request, so i connected the DELETE commands with a ";"... but it fails always.
var sql_string = "DELETE FROM user_tables WHERE name = 'Testbase';";
sql_string += "DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase';";
sql_string += "DELETE FROM user_tables_rules WHERE parent_table_name = 'Testbase';";
sql_string += "DELETE FROM user_tables_columns WHERE parent_table_name = 'Testbase';";
connection.query(sql_string, function(err, rows, fields) {
if (err) throw err;
res.send('true');
});
It throws this 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 'DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase';DELETE FR' at line 1
But if i paste this SQL in PhpMyAdmin it is always successful...
If i write it in single query's its succeed, too.
connection.query("DELETE FROM user_tables WHERE name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_structure WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_rules WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
connection.query("DELETE FROM user_tables_columns WHERE parent_table_name = 'Testbase'", function(err, rows, fields) {
if (err) throw err;
res.send('true');
});
});
});
});
Thanks for help!
I guess you are using node-mysql. (but should also work for node-mysql2)
The docs says:
Support for multiple statements is disabled for security reasons (it
allows for SQL injection attacks if values are not properly escaped).
Multiple statement queries
To use this feature you have to enable it for your connection:
var connection = mysql.createConnection({multipleStatements: true});
Once enabled, you can execute queries with multiple statements by separating each statement with a semi-colon ;. Result will be an array for each statement.
Example
connection.query('SELECT ?; SELECT ?', [1, 2], function(err, results) {
if (err) throw err;
// `results` is an array with one element for every statement in the query:
console.log(results[0]); // [{1: 1}]
console.log(results[1]); // [{2: 2}]
});
So if you have enabled the multipleStatements, your first code should work.
Using "multiplestatements: true" like shown below worked for me
var connection = mysql.createConnection({
host: 'localhost',
user: 'root',
password: '',
database: '',
multipleStatements: true
});
connection.connect();
var sql = "CREATE TABLE test(id INT DEFAULT 1, name VARCHAR(50));ALTER TABLE test ADD age VARCHAR(10);";
connection.query(sql, function(error, results, fields) {
if (error) {
throw error;
}
});
To Fetch Data from DB(SQL), the following function would work accurately
router.get('/', function messageFunction(req, res){
//res.send('Hi Dear Rasikh, Welcome to Test Page.') //=> One Way
dbConn.query('SELECT COUNT(name) as counted, name, last_name, phone, email from students',
function (err, rows, fields) { // another Way
if (err) throw err
dbConn.query('SELECT name, author from books',
function (err, rowsBook, fields) { // another Way
if (err) throw err
// console.log('The counted is: ', rows[0].counted); //=> Display in console
// res.send('Hi Dear Rasikh, Welcome to Test Page.'+ rows[0].counted) //=> Display in blank page
res.render('main/index',{data:rows, myData:rowsBook});
})
});
});
I'm using MySQL for the first time, and I'm struggling to properly preparing statements and escaping query values. Here's where I'm at:
connection.connect();
formatDate(function(date){
var sql = "INSERT INTO coffee_tbl (coffee_name, coffee_type, submission_date) VALUES ?";
var inserts = [req.param('name'), req.param('type'), date];
var queryString = mysql.format(sql, inserts);
console.log(queryString)
connection.query(queryString, function(err, results){
if(err) serverError(res, err);
else{
res.redirect('/view_coffee');
}
});
});
connection.end();
I'm using the 'mysql' node.js module by felixge.
You need a ? per value. Also, be sure to use a connection pool.
formatDate(function(date){
var sql = [
"INSERT INTO coffee_tbl SET",
" coffee_name=?",
",coffee_type=?",
",submission_date=?"
].join('');
var inserts = [req.param('name'), req.param('type'), date];
pool.getConnection(function(err, connection) {
if(err) return console.error(err);
connection.query(sql, inserts, function(err, results) {
connection.release();
if(err) return console.error(err);
res.redirect('/view_coffee');
});
});
});
To setup a connection pool:
var pool = mysql.createPool({
host: process.env.MYSQL_HOST,
user: process.env.MYSQL_USER,
password: process.env.MYSQL_PASS,
database: process.env.MYSQL_NAME,
connectionLimit: 8
});
Use environment variables for your mysql authentication information so as to not commit authentication information to a repo.
You only have one placeholder in your sql var, but you are trying to pass three values in your inserts var. You want to modify your sql var to have three placeholder like this:
var sql = "INSERT INTO coffee_tbl (coffee_name, coffee_type, submission_date) VALUES (?, ?, ?)";