CODEWITHSUNDEEP
iosswift3realmdatabase-migration
amagain
amagain

Reputation: 2072

Realm Database Migration, adding new Object and modifying old

I have a realm database Object as defined in the class

class TPDailyRashifal: Object, Mappable {

    public required convenience init?(map: Map) {
      self.init()
      mapping(map: map)
    }

    dynamic var rashi: String = ""
    dynamic var rashiDetail: String = ""

    public func mapping(map: Map) {
      rashi       <- map["rashi"]
      rashiDetail <- map["rashifal"]
    }
    override static func primaryKey() -> String {
      return "rashi"
    }
}

I would like to add these three variables in my Object as follows 

dynamic var date: String = ""
dynamic var fallIds: String = ""
dynamic var rating: Int = 0

I know my mapping function would have to be modified and to add followings.

    date        <- map["date"]
    fallIds     <- map["fallIds"]
    rating      <- map["rating"]

But my 

dynamic var rashi: String = ""

definition has to change to 

dynamic var rashi:  Int = 0

In my Appdelegate, applicationDidFinishLaunchingWithOptions function, I have written 

    Realm.Configuration.defaultConfiguration = Realm.Configuration(
        schemaVersion: 1,
        migrationBlock: { migration, oldSchemaVersion in
            if (oldSchemaVersion < 1) {
                print("Schema Version 0")
                // The enumerateObjects(ofType:_:) method iterates
                // over every Person object stored in the Realm file
                migration.enumerateObjects(ofType: TPDailyRashifal.className()) { oldObject, newObject in
                    // combine name fields into a single field
                    /*
                     To add these variables during migration
                     dynamic var date: String = ""
                     dynamic var fallIds: String = ""
                     dynamic var rating: Int = 0
                     */
                    let oldRashi = oldObject?["id"] as? Int
                 //   let newRashiId = 


                }
            }
    })

I am confused to where should I begin adding the new variables in the Realm Object. I have referred to other questions, but I couldn't catch up with them.

Upvotes: 0

Views: 1317

Answers (2)

amagain
amagain

Reputation: 2072

Smarcat was partially right but then I had to do some research and here it is.

    Realm.Configuration.defaultConfiguration = Realm.Configuration(
        schemaVersion: 1,
        migrationBlock: { migration, oldSchemaVersion in
            if (oldSchemaVersion < 1) {
                print("Schema Version 0")
                // The enumerateObjects(ofType:_:) method iterates
                // over every Person object stored in the Realm file
                migration.enumerateObjects(ofType: TPDailyRashifal.className()) { oldObject, newObject in
                    // combine name fields into a single field

                    newObject!["date"] = ""
                    newObject!["fallIds"] = ""
                    newObject!["rating"] = 0
                      newObject!["rashi2"] = 0
                }
                migration.renameProperty(onType: TPDailyRashifal.className(), from: "rashi", to: "rashi2")

            }
    })

I had to use migration.renameProperty block to rename rashi to rashi2.

Upvotes: 2

Smartcat
Smartcat

Reputation: 2882

I do believe you'll need to rename your "rashi" to something else (assuming the new Int will be "rashi2" in below example).

migration.enumerateObjects(ofType: TPDailyRashifal.className()) { oldObject, newObject in
    newObject!["date"] = ""
    newObject!["fallIds"] = ""
    newObject!["rating"] = 0
    newObject!["rashi2"] = 0   // this version has a rashi2 (Int) instead of a rashi (String).
}

Also note, if you need to convert the old rashi to the rashi2 via a string-to-int conversion, you can do so by using oldObject["rashi"] within this closure to obtain the old string, then convert it and set rashi2 to it rather than to 0.

Upvotes: 0

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