I want to make a function that query data to MySQL, and wait for the result.
const results = await message.client.db.query("SELECT * FROM TABLE WHERE condition");
console.log(results);
My issue is that results doesn't contain the raw data as I would expect it, but a query object :
<ref *1> Query {
_events: [Object: null prototype] {
error: [Function (anonymous)],
packet: [Function (anonymous)],
timeout: [Function (anonymous)],
end: [Function (anonymous)]
},
_eventsCount: 4,
_maxListeners: undefined,
_callback: [Function (anonymous)],
...
_connectCalled: true,
state: 'authenticated',
threadId: 27,
[Symbol(kCapture)]: false
},
[Symbol(kCapture)]: false
}
I have been looking for a doc on that Object, and I couldn't find it. I suppose it is a sort of Promise, as the Query object is returned before the results are received :
console.log("1 - Before Query");
const results = await message.client.db.query("SELECT * FROM TABLE WHERE condition", async function (err, result, fields) {
if (err) throw err;
console.log("2 - Query result : ");
console.log(result);
});
console.log("3 - After Query");
console.log(results);
OUTPUT :
1 - Before Query
3 - After Query
<The Query Object>
2 - Query result :
<An array with my data>
I have seen a lot of example where people use await connection.query("...") to wait for the results, and I don't understand where does this Query object comes from.
I know I can wait for the result with something like that :
message.client.db.query("SELECT * FROM TABLE WHERE condition", async function (err, result, fields) {
if (err) throw err;
do_something(result);
});
But I first find it really heavy, and hard to use when you do a lot of requests.
Also I need an async function that return a value from database, and since await connection.query("...") can't wait for the result, I don't know how to do it.
If you are using mysql2 package to connect to the database you can do something like this:
await con1.promise().query("your query here")
.then( ([rows,fields]) => {
your var = rows[0]['field1'];
return nome_completo;
})
.catch(console.log)
Where con1 is the connection you defined. With promise() you are promisifying your query so you can use await