Design Pattern for Realm Database Swift 3.1 - Singleton

Design Pattern for Realm Database Swift 3.1 - Singleton

Realm has a rather clever internal caching system where previous instances of Realm are held onto and recycled each time a call like let realm = try! Realm() occurs. As such, it's not really necessary, nor recommended to try and incorporate a Realm instance itself into a singleton.

If you want to heavily customise your Realm instance's settings, you'll normally do that through a Realm Configuration object, which is static and thread-safe. If that's the case, it would be more appropriate to have a singleton (or even just a static class method) that returns the appropriate Configuration object when you need to create a new Realm instance.

that thing in swift has a page on how to create singletons in Swift, and it's essentially just a single static property of a class implementation:

class SomeManager {
    static let sharedInstance = SomeManager()
}

How to set the default SyncConfiguration for Realm, so I can get it in multiple ViewControlllers without redundant code?

The problem is that you are using an async method to configure your Realm, but you don't call the print inside the completion handler of your method. You should only present your viewcontoller once your asynchronous call has finished.

Find two consecutive rows

Assuming the rows have sequential IDs, something like this may be what you're looking for:

select top 1 * 
from 
Bills b1
inner join Bills b2 on b1.id = b2.id - 1
where
b1.IsEstimate = 1 and b2.IsEstimate = 1
order by
b1.BillDate desc

Find two consecutive rows

Assuming the rows have sequential IDs, something like this may be what you're looking for:

select top 1 * 
from 
Bills b1
inner join Bills b2 on b1.id = b2.id - 1
where
b1.IsEstimate = 1 and b2.IsEstimate = 1
order by
b1.BillDate desc

Find two consecutive rows

Assuming the rows have sequential IDs, something like this may be what you're looking for:

select top 1 * 
from 
Bills b1
inner join Bills b2 on b1.id = b2.id - 1
where
b1.IsEstimate = 1 and b2.IsEstimate = 1
order by
b1.BillDate desc

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