Node JS mySQL tripple query and lost of information - mysql

Question

In my application I have a two different tables related to each other by ID of the first one (one to many relation). It should first collect the data from the frontend-side by in JSON format which looks like this:
cancellation = {
name: someting
id: someting
rule =
[
{someting}, {something}, {something}
]
}
One table would be for cancellation and the second one for the rules. If I want to put those information in this order I need first insert one record for cancellation. Then make a query to find out what is an ID of this record in the database and after that insert all rules using this ID as a foreign key. But since Node JS is asynchronous before I fetch the information about the ID of the record program stars to execute rest of the code and consider this variable as undefined.
app.post('/databaseSend/cancellation', function(req,res){
var cancellationReceived = req.body;
var cancellationID;
var rules = [];
var cancellation = [];
cancellation[0] =
[
cancellationReceived.name,
cancellationReceived.id
]
// inserting data into cancellation table
connection.query("INSERT INTO cancellations (name, User_ID) VALUES ?", [cancellation],
function(err,results){
if(err){console.log(err)}
}
)
//fetching ID of the current record
connection.query("SELECT id FROM cancellations WHERE User_ID = ? AND name = ?", [cancellationReceived.id, cancellationReceived.name],
function(err, results){
var cancellationID = results[0].id;
});
//assigning ID to use it as a foreign key
for(var i = 0; i < cancellationReceived.rule.length; i++)
{
rules[i] =
[
cancellationReceived.rule[i].daysBefore,
cancellationReceived.rule[i].fee,
cancellationReceived.rule[i].type,
cancellationID
]
}
for(var i = 0; i < rules.length; i++)
{
console.log(rules[i]); // ID is undefined
}
});
How can I solve this problem? I tried to use setTimeout for pausing my code but it did not change anything.
And I use this node module for mysql - > https://github.com/mysqljs/mysql

Answer 1

The best way to solve this problem is RTFM.
connection.query('INSERT INTO cancellations (name, user_id) values ?', [cancellation], function(err, results) {
if (err)
return console.error(err);
// See https://github.com/mysqljs/mysql#getting-the-id-of-an-inserted-row
var cancellation_id = results.insertId;
// Generate sql for rules, join them by ; and execute as one query
// See https://github.com/mysqljs/mysql#multiple-statement-queries
connection.query(sqls, function(err) {
if (err)
return console.error(err);
// Send response here
});
})