Unique documents using multiple values in Mongoose Schema

Question

I have a special case where our collection needs to make sure each document is unique based on a combination of the email address, and the sweepstakes_id. I've looked all over, but I can't find how to accomplish this type of validation.

Schema definition:

var submissionSchema = new Schema({     client_id: {         type: Schema.Types.ObjectId,         ref: 'Client',         index: true     },     sweepstakes_id: {         type: Schema.Types.ObjectId,         ref: 'Sweepstakes',         index: true     },     email: {         type: String,         index: true    },    data: {         type: Schema.Types.Mixed,         default: []    } }); 

Answer 1

You can enforce that using a unique index that includes both fields:

submissionSchema.index({ email: 1, sweepstakes_id: 1 }, { unique: true });