如何在mongodb中找到JavaScript数组中所有元素的匹配项？

Question

I am trying to attempt to search all matches in the mongodb database that I have created for each of the different elements in an array. I have the following code

var fiatList = ['EUR', 'AUD', 'BRL', 'CAD', 'CHF', 'CNY', 'CZK', 'DKK'];

function updateFiatTotal() {

    fiatList.forEach(function(entry){
    console.log('Calculating Fiat total data');
    models.Market.find({ quote: { $in: entry } }, function(err, markets) {
    if (err) return console.log(err);
    console.log('markets');
     });
  });
}

For some reason this is not returning anything for the markets that I am trying to print out into the database. If anyone could give me pointers on why it is not correctly querying the mongodb database it would be apprecaited

Answer 1

$in expects an array, so you'd have to pass the fiatList as parameter. That is, if you are looking for a document where quote: ['EUR', 'AUD', 'BRL', 'CAD', 'CHF', 'CNY', 'CZK', 'DKK']

models.Market.find({
    quote: fiatList
}, function(err, markets) {
    if (err) return console.log(err);
    console.log('markets');

});

Now if you are looking for a document that could have one of these values. Example: quote:['EUR', 'AUD'], quote:['CZK', 'CHF'] Then you could do this:

fiatList.forEach(function(entry) {

    models.Market.find({
        quote: entry
    }, function(err, markets) {
        if (err) return console.log(err);
        console.log('markets');

    });
});

This way you could get the same document if quote:['CZK', 'CHF'] , cause you would get it once for

models.Market.find({
    quote: 'CZK'
})

and once for

models.Market.find({
    quote: 'CHF'
}) 

Also if you still don't get any results, check if your collection is called market instead of Market . I've heard before that people created the collection in mongoose with capital but in mongodb it was written lowercase.