Does CouchDB supports referential integrity?

Question

I am new to CouchDB and learning about it. I did not come across CouchDB support for referential integrity. Can we create a foreign key for a field in the CouchDB document?

Answer 1

While not possible to create an FK constraint, it is possible using Couch's Validate function

function(newDoc, oldDoc, userCtx, secObj) {
    if(newDoc && newDoc.type) switch(newDoc.type){
        case 'fish':
            var allSpecies = ['trout','goldfish'];
            if(!allSpecies.contains(newDoc.species)){
                throw({forbidden : 'fish must be of a know species'});
            }
            break;
        case 'mammals':
            if(!['M','F'].contains(newDoc.sex)){
                throw({forbidden : 'mammals must have their sex listed'});
            }
            break;
    }
}

Now, if a person were really clever (I'm not), they might do a call out to the DB itself for the list of Species... that would be a foreign key.

You may also want to read up on: How do I DRY up my CouchDB views?