What is the meaning `required` in mongoose Schema?

Question

I am writing a mongoose schema, and I would like to understand the properties of the same.

Here is my schema:

var UserSchema = new Schema({
        name: String,
        username: { type: String, required: true, index: { unique: true }},
        password: { type: String, required: true, select: false }
});

1. Why required is not declared for `name' - ?
2. Why required declared?
3. What is select - true/false -means?
4. When the index - should declared any why?

Answer 1

Why required is not declared for `name' - ?

Answer: When a field is mandatory to fill then in that case we mention it as required. So here "name" is not required or mandatory field.

Why `required' declared?

Answer: As mentioned above, When a field is mandatory to be filled then in that case we mention it as required.

What is select - true/false -means?

Answer: This means that it will not be returned by default in the data when you fetch the document. you can specify if this path should be included or excluded from query results by default.

Schema options

When the index - should declared any why?

Answer: Index should be declared when you are searching data on that field frequently so when you create indexing on that field in that case it do not search that field in all the collections it will search value for that field using index and will return result very quickly.

How indexes work in mongodb