trying to get data from two requests - mysql

Question

I try to get data from two requests on two table. But I've some difficulties to get back them as I expect. I've some group andfor each group I want to get the list of all element included in this group. So I want all groups id and all items related to them.
So I execute the second query into the callback of the first into a loop to execute the query as many time as I've results from the first query. I think thant my problem come from the loop
Groupe.getGroupeAndEqs = function getGroupeAndEqs(result) {
sql.query("SELECT DISTINCT idGrp FROM groupe_equipement", function (err, res){
if (err) {
console.log("error: ", err);
result(err, null);
}
else {
for (var i = 0; i < res.length; i++){
sql.query("SELECT e.nom FROM equipement as e, groupe_equipement as g where g.idGrp=? AND e.id = g.idEq", res[i].idGrp, function(err, res2){
if(err){
console.log("error: ", err);
result(err, null);
}
else{
// result(null, res);
//I try to create an attribute with the result of the second query
res[i].equipements += res2;
//console.log(res[i]);
//resu += result(null, res);
console.log(res2);
}
});
}
result(null, res);
}
});
}
I only get the result of the first query

Answer 1

You can do the whole thing in a single query. That may half your total process time. Check this query.
select g.idGrp, group_concat(distinct e.nom) from equipement e
inner join groupe_equipement g
on e.id = g.idEq
group by g.idGrp