CODEWITHSUNDEEP
swiftrealm
Reshad
Reshad

Reputation: 2652

Storing objects with unique identifiers ( primary keys )

Hello I have this object where I need to create unique identifiers ( primary keys ) for updating, retrieving etc from the realm database by identifier. Since realm doesn't support this out of the box I wanted to create my own way of identifying them.

class Swing: Object {

    dynamic var latitude : Double = 0.0
    dynamic var longitute : Double = 0.0
    dynamic var speed : Double = 0.0
    dynamic var date : NSDate = NSDate()
}

Can I use the NSDate as a unique id or should I go with a new column called id and use UUIDString? and is this always unique for a new object or only per device? 

dynamic var id = NSUUID().UUIDString

What solution would be more failsafe/accurate?

Upvotes: 1

Views: 436

Answers (1)

TiM
TiM

Reputation: 15991

It's probably safer to simply have an NSUUID as your primary key. They're guaranteed to be unique, and depending on the types of NSDate values you're saving to your property, uniqueness definitely can't be guaranteed.

NSUUID is a 128-bit randomly generated value, so even on different devices, the odds of the same string being generated twice is astronomically small.

class Swing: Object {
    dynamic var id = NSUUID().UUIDString
    dynamic var latitude : Double = 0.0
    dynamic var longitute : Double = 0.0
    dynamic var speed : Double = 0.0
    dynamic var date : NSDate = NSDate()

    override class func primaryKey() -> String? {
        return "id"
    }
}

Upvotes: 4

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