Getting results of a MongoDB query to use in a select menu

user_17265725 0
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I'm working on a website that allows you to search for people in a database based on location. Initially, the dropdown menu (select) is populated with provinces that available people are in. I'm trying to use a mongo query to populate that select menu. But when I try to get the values outside the function, it does not work and the select menu turns up empty.

import * as React from "react";
import axios from "axios";
  
const Locations = () => {

  let options = null;

  function axiosTest() {
    // This is a server link i created that runs a query that returns distinct provinces from the database
    const promise = axios.get("/api/v2/people/provinces");
    const dataPromise = promise.then(result => result.data).then(data => {console.log(data);return data;});
    // The console.log() above displays all the objects that are in the query given by the server link in an array
    // e.g. ['British Columbia', 'Alberta', 'Saskatchewan', etc.]
  }
  
  var type = axiosTest();
  console.log(type);  // now it displays it as "undefined"

  if (type) {
    options = type.map((el) => <option key={el}>{el}</option>);
  }

  return (
    <div
      style={{
        padding: "16px",
        margin: "16px",
      }}
    >
      <form>
        <div>
          <select>
            {
              /** This is where we have used our options variable */
              options
              // and the select menu is shown as blank, because it doesn't have any options to fill it with
            }
          </select>
        </div>
      </form>
    </div>
  );
};
  
export default Locations;

Can someone please help me get this to work? Is it something to do with Threads and Concurrency? I'm unfortunately rusty at that.

reactjs mongodb drop-down-menu javascript
1 Answers

Function axiosTest() does not return anything. You should specify change your code so the function would return the result of DB query. You can also change .then() syntax with async/await so your code would become more readable.

const Locations = async () => {

  let options = null;

  function axiosTest() {
    return axios.get("/api/v2/people/provinces");
  }
  
  var type = await axiosTest();
  console.log(type); 

  ...

};
user_143898300
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