I have a schema in which in one of the field i wanted it to store array of values. The schema is given below:

const memberSchema=new mongoose.Schema({
  id:{
    type:String,
    unique:true
  },
 prefCurrency:{
    type:String,
    default:'AUD',
    required:false
  },
});

In the front end part, The user will select multiple currencies and which can be stored in the prefCurrency field of schema. The front end code is given below:

export default function MemberInformation() {
    const { t } = useTranslation();
    const[memberData,setMemberData]=useState([]);
    const [member,setMember]=useState({id:"",prefCurrency:""})
        var name,valueV;
        const handleInputs=e=>{
          console.log("Updated ",member)
          name=e.target.name;
          valueV=e.target.value;
          setMember({...member,[name]:valueV})
        }
const postData= ()=>{
          setMemberData({...memberData,...member})
          const {id,prefCurrency}=member;
          var UpdatedMemInfo ={id,prefCurrency};
          axios.put('/memberInfoUpdate', UpdatedMemInfo)
          .then( res => {
            alert('Updated successfully!');
           }   
          )
          .catch(err => {
            console.log(err.response);
            alert('An error occurred! Try submitting the form again.');
          });
       } 
useEffect(() => {
        async function fetchBooks() {
          const response = await fetch('/memberinfo');
          const json = await response.json();
          setMemberData(json.memberLogin);
          setMember(json.memberLogin);
          console.log(json.memberLogin)
      }
      fetchBooks();
  },[]);
return (
<Form.Select aria-label="Floating label select example" name="prefCurrency" value={member.prefCurrency} onChange={e=>handleInputs(e)}>
                        <span><ReactCountryFlag countryCode="AU" svg style={myStyle}/></span> 
                        <option value="AUD" name="prefCurrency">AUD</option>
                        <option value="CAD" name="prefCurrency">CAD</option>
                        <option value="CHF" name="prefCurrency">CHF</option>
                        <option value="CNY" name="prefCurrency">CNY</option>
                   </Form.Select>
 <Button variant="success" onClick={()=>postData()}>
                Save Changes
              </Button>
)
}

As in the above code, only one value can be selected and stored into the MongoDB but i want select multiple values and store in the form of array in the prefCurrency field of the schema and then retrieve it from the database to display it. What will be the code changes here?

The API for posting the above data in database is given below:

router.put('/memberInfoUpdate', async (req, res) => {
  const {id,prefCurrency}=req.body;
  var _id = req.body.id;
  var UpdatedMemInfo = {
    id:id,
    prefCurrency:prefCurrency  
  };
  Member.findOneAndUpdate(_id, UpdatedMemInfo, { new: true }, function(
    err,
    UpdatedMemInfo
  ) {
    if (err) {
      console.log("err", err);
      res.status(500).send(err);
    } else {
      console.log("success");
      res.send(UpdatedMemInfo);
    }
  });
  });

The above update API is just for one value in the prefCurrency field but i want to have multiple selected values in it.

CodePudding user response：

The prefCurrency Schema would look like this for storing array values. const memberSchema=new mongoose.Schema({

  id:{
    type:String,
    unique:true
  },
 prefCurrency:{
    type:Array,
    default:'AUD',
    required:false
  },
});

And the query for updating the prefCurrency is

 var UpdatedMemInfo = {
    id:id,
    prefCurrency:[prefCurrency]  
  };

This will take array of values and update it.