Await with loop returns promise

Question

I am trying to fetch something through a loop and than return the value after await. However it just returns a array of promises even though I am awaiting?

My goal is to get values from the https://frost.met.no/sources/v0.jsonld?types=SensorSystem&elements=${element}&country=NO&fields=id%2Cvalidfrom with the different element and it works the problem is just that I cant seem to return the real value is something is wrong with the way I Await it.

const fetchDetails=["mean(air_temperature P1M)","max(air_temperature P1M)","min(air_temperature P1M)"]
let status = await fetchData(fetchDetails);
//this returns promise but I want to await for the results.

async function fetchData(fetchDetails) {
  try {
    await db.query("DROP TABLE IF EXISTS weather;");
    await db.query(
      `CREATE TABLE weather(
          weather_id SERIAL UNIQUE PRIMARY KEY NOT NULL,
          source_id VARCHAR(10) NOT NULL,
          valid_from VARCHAR(50),
          element VARCHAR(50),
          CONSTRAINT fk_source
                  FOREIGN KEY(source_id) 
                  REFERENCES sources(source_id)
                  ON DELETE CASCADE 
      );`
    );
    const sources = await db.query("select (source_id) from sources;");
    console.log(sources.rows)
    const details = await fetchDetails.map(async (element) => {
      await fetch(
        `https://frost.met.no/sources/v0.jsonld?types=SensorSystem&elements=${element}&country=NO&fields=id%2Cvalidfrom`,
        {
          method: "get",
          body: JSON.stringify(),
          headers: {
            Authorization:
              "Basic YjVlNmEzODEtZmFjNS00ZDA4LWIwNjktODcwMzBlY2JkNTFjOg==",
          },
        }
      )
        .then((res) => res.json())
        .then(async (data) => {
          const id = "SN59450"
          let sqlInsert = data.data.filter(e => e !== null && sources.rows.some(b => b.source_id === e.id)).map((value) => {
            return `('${value.id}','${value.validFrom}','${element}')`
          })
          //fs.writeFileSync('./data6.json', JSON.stringify(sqlInsert, null, 2), 'utf-8');
          let input = await db.query("INSERT INTO weather(source_id, valid_from, element) values" + sqlInsert+"returning *");
          return input.rows;
        });
    })
//Details here is also a promise how can I wait for the loop to finish
    return(details)
  }
  catch (err) {
    console.log(err)
  }
}

Answer 1

Use Promise.all(). Like this

async function fetchData(fetchDetails) {
  try {
    await db.query("DROP TABLE IF EXISTS weather;");
    await db.query(
      `CREATE TABLE weather(
          weather_id SERIAL UNIQUE PRIMARY KEY NOT NULL,
          source_id VARCHAR(10) NOT NULL,
          valid_from VARCHAR(50),
          element VARCHAR(50),
          CONSTRAINT fk_source
                  FOREIGN KEY(source_id) 
                  REFERENCES sources(source_id)
                  ON DELETE CASCADE 
      );`
    );
    const sources = await db.query("select (source_id) from sources;");
    console.log(sources.rows)
    const details = await Promise.all(fetchDetails.map(async (element) => {
      await fetch(
        `https://frost.met.no/sources/v0.jsonld?types=SensorSystem&elements=${element}&country=NO&fields=id%2Cvalidfrom`,
        {
          method: "get",
          body: JSON.stringify(),
          headers: {
            Authorization:
              "Basic YjVlNmEzODEtZmFjNS00ZDA4LWIwNjktODcwMzBlY2JkNTFjOg==",
          },
        }
      )
        .then((res) => res.json())
        .then(async (data) => {
          const id = "SN59450"
          let sqlInsert = data.data.filter(e => e !== null && sources.rows.some(b => b.source_id === e.id)).map((value) => {
            return `('${value.id}','${value.validFrom}','${element}')`
          })
          //fs.writeFileSync('./data6.json', JSON.stringify(sqlInsert, null, 2), 'utf-8');
          let input = await db.query("INSERT INTO weather(source_id, valid_from, element) values" + sqlInsert+"returning *");
          return input.rows;
        });
    }))
//Details here is also a promise how can I wait for the loop to finish
    return(details)
  }
  catch (err) {
    console.log(err)
  }
}