Good afternoon, could anyone help me on node.js? My question is how could I store the values of a sql query in a variable as an example.
let id = connection.query('SELECT * FROM marca ORDER BY id DESC LIMIT 1', function(err,result){
if(err)
throw err;
else{
id = result[0];
console.log("ID!!: "+id.id);
}
});
Take a look at the documentation Escaping query values . Your alternatives are:
mysql.escape() , connection.escape() or pool.escape()
var userId = 'some user provided value';
var sql = 'SELECT * FROM users WHERE id = ' + connection.escape(userId);
connection.query(sql, function (error, results, fields) {
if (error) throw error;
// ...
});
? character as placeholder
connection.query(
'SELECT * FROM users WHERE id = ?',
[userId],
function (error, results, fields) {
if (error) throw error;
// ...
});
In your case, you can do something like this
var post = {id: 1, title: 'Hello MySQL'};
var query = connection.query(
'INSERT INTO posts SET ?',
post,
function (error, results, fields) {
if (error) throw error;
// ...
});
console.log(query.sql); // INSERT INTO posts SET 'id' = 1, 'title' = 'Hello MySQL'
Victor, let me get this straight. You want to store the result of the SQL query, in a variable to use later, right?
I believe a promise can solve this situation:
const consulta = () => {
return new Promise((resolve, reject) => {
const query = 'SELECT * FROM marca ORDER BY id DESC LIMIT 1';
connection.query(query, (err, result) => {
if(err){
return reject(err);
}
return resolve(result);
})
}
})
consulta().then(result => {
console.log('ID: ${result.id}');
}).catch(err => {
throw err;
});
In this case, consulta is a promise of the query in the database. When calling a promise , we have two arguments: Resolve and Reject .
The functions resolve and reject , when calls, resolve (on success) or reject (when an error occurs) the promise respectively.