How to get list of field names of collection in MongoDB

In this article, we will see how to get list field names with their field types of collection in MongoDB. It contains two steps:

Step1: Write a function:
Lets create a function.

 var fieldNames = function(schema, i, limit) {
    var i = (typeof i !== 'undefined') ? i : 1;
    var limit = (typeof limit !== 'undefined') ? limit : false;
    var type = '';
    var array = false;

    for (key in schema) {
        type = typeof schema[key];
        array = (schema[key] instanceof Array) ? true : false;

        if (type === 'object') {
            print(Array(i).join('    ') + key+' <'+((array) ? 'array' : type)+'>:');
            schemafy(schema[key], i+1, array);
        } else {
            print(Array(i).join('    ') + key+' <'+type+'>');
        }

        if (limit) {
            break;
        }
    }
}

Step2: Apply the above function:
Lets switch to the database where collection exists.

use m201

Then run:

  fieldNames(db.people.findOne())
Output:
 _id