swift - 现有 Realm 数据库无法在 swift 3.1 xcode 8 中工作

Question

我创建的应用程序使用现有的数据库 Realm 2.3.0 和 swift 3.1 xcode 8.3。但是当我尝试访问 Realm 数据库时。有错误。

Could not access database: Error Domain=io.realm Code=2 "Unable to open a realm at path '/Users/dodipurnomo/Library/Developer/CoreSimulator/Devices/858C796B-CBA8-424B-9A97-0893304B758B/data/Containers/Data/Application/A2D910EE-AAC5-4836-9FE7-97F744E802E5/Documents/Conversio.realm': Unsupported Realm file format version." UserInfo={NSFilePath=/Users/dodipurnomo/Library/Developer/CoreSimulator/Devices/858C796B-CBA8-424B-9A97-0893304B758B/data/Containers/Data/Application/A2D910EE-AAC5-4836-9FE7-97F744E802E5/Documents/Conversio.realm,

以上是我尝试执行数据库时的错误消息。至于处理数据库 Realm 的类如下:

import RealmSwift
import UIKit

class DBManager{
//MARK: - Singleton shared intance

static let sharedIntance = DBManager()
//MARK: - overide init function in realm

static var realm: Realm {
    get {
        do {
            let realm = try Realm()
            return realm
        }
        catch {
            print("Could not access database: ", error)
        }
        return self.realm
    }
}

public static func write(realm: Realm, writeClosure: () -> ()) {
    do {
        try realm.write {
            writeClosure()
        }
    } catch {
        print("Could not write to database: ", error)
    }
}

public static func query(realm: Realm,queryClosure: () -> ()){

}


func save(entityList: [Object], shouldUpdate update: Bool = false) {
    DBManager.realm.beginWrite()
    for entity in entityList {
        if let key = type(of: entity).primaryKey(), let value = entity[key] , update {
            if let existingObject = DBManager.realm.object(ofType: type(of: entity), forPrimaryKey: value as AnyObject) {
                let relationships = existingObject.objectSchema.properties.filter {
                    $0.type == .array
                }
                for relationship in relationships {
                    if let newObjectRelationship = entity[relationship.name] as? ListBase , newObjectRelationship.count == 0 {
                        entity[relationship.name] = existingObject[relationship.name]
                    }
                }
            }
        }
        DBManager.realm.add(entity, update: update)
    }

    do {
        try DBManager.realm.commitWrite()
    } catch let writeError {
        debugPrint("Unable to commit write: \(writeError)")
    }

    DBManager.realm.refresh()
 }
}

And I set the Realm in appdelegate as follows:

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    let desPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
    let fullDesPath = URL(fileURLWithPath: desPath).appendingPathComponent("Conversio.realm")


    var config = Realm.Configuration()
    config.deleteRealmIfMigrationNeeded = true
    config.fileURL = fullDesPath
    Realm.Configuration.defaultConfiguration = config
    chekDB()
    return true
}


//chek database
func chekDB() {
    let bundleDB = Bundle.main.path(forResource: "Conversio", ofType: "realm")
    let desPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
    let fileManager = FileManager.default
    let fullDesPath = URL(fileURLWithPath: desPath).appendingPathComponent("Conversio.realm")
    let fullDestPathString = String(describing: fullDesPath)
    if fileManager.fileExists(atPath: fullDesPath.path){
        print("Database file is exis !")
        print(fileManager.fileExists(atPath: bundleDB!))
    }else{
        do{
            try fileManager.copyItem(atPath: bundleDB!, toPath: fullDesPath.path)
        }catch{
            print("error encured while copying file to directori \(fullDestPathString)")
        }
    }
}

Answer 1

您收到的错误消息意味着 Realm 文件是使用较新版本的 Realm 创建的，因此请将 Realm 更新到最新版本。

另外请记住，如果您使用使用较新版本 Realm 的 Realm 浏览器打开 Realm ，它会要求您转换文件格式。如果你这样做，你可以用旧版本的 realm-cocoa 打开这个 Realm 。