How to completely remove Realm database from iOS?

问题:

Now I get error Property types for 'value' property do not match. Old type 'float', new type 'double' How to clear database or migrate is successfully?

回答1:

To completely delete the Realm file from disk and start from scratch, it's simply a matter of using NSFileManager to manually delete it.

For example, to delete the default Realm file:

NSFileManager.defaultManager().removeItemAtURL(Realm.Configuration.defaultConfiguration.fileURL!)

If you want to preserve the Realm file, but completely empty it of objects, you can call deleteAll() to do so:

let realm = try! Realm()
try! realm.write {
  realm.deleteAll()
}

Update: I feel I neglected to mention this in my original answer. If you choose to delete the Realm file from disk, you must do so before you've opened it on any threads in your app. Once it's opened, Realm will internally cache a reference to it, which won't be released even if the file is deleted.

If you absolutely do need to open the Realm file to check its contents before deletion, you can enclose it in an autoreleasepool to do this.

回答2:

This is how to do in swift 4.1:

FileManager.default.removeItem(at:Realm.Configuration.defaultConfiguration.fileURL!)  

回答3:

Whilst the other comments are right, you should really look at : https://realm.io/docs/swift/latest/#migrations

It gives a super clear explanation of how to do migration, and it's really simple, and far better deleting everything if it can be helped.

回答4:

In addition to using NSFileManager to remove the file, also remove the .lock file and .management folder as well. Otherwise, if you try to recreate the realm file with the same name, it will give an error saying it can't find it

回答5:

Swift 4.2:

func remove(realmURL: URL) {
        let realmURLs = [
            realmURL,
            realmURL.appendingPathExtension("lock"),
            realmURL.appendingPathExtension("note"),
            realmURL.appendingPathExtension("management"),
            ]
        for URL in realmURLs {
            try? FileManager.default.removeItem(at: URL)
        }
let url = Realm.Configuration.defaultConfiguration.fileURL!
remove(realmURL: url)

回答6:

Have you tried

   let realm = try! Realm()
   realm.deleteAllObjects() 

You could also try deleting the realm off the device by plugging it into the computer, going to Xcode and then Devices, and then finding the current realm there and deleting it.

回答7:

Swift 4.2 To remove database:

func remove(realmURL: URL) {
        let realmURLs = [
            realmURL,
            realmURL.appendingPathExtension("lock"),
            realmURL.appendingPathExtension("note"),
            realmURL.appendingPathExtension("management"),
            ]
        for URL in realmURLs {
            try? FileManager.default.removeItem(at: URL)
        }
let url = Realm.Configuration.defaultConfiguration.fileURL!
remove(realmURL: url)

To clear database:

try? realm.write {
    realm.deleteAll()
}