• How to create a unique id in iOS with Swift

    let uuid = UUID().uuidString

  • How to migrate FMDB along with new App releases

    • Tool: FMDBMigrationManager
    • How: Treat your database like git repository, add modifications like commits, and apply commits to the current state
    • Steps:
      • install FMDBMigrationManager with pod
      • New a FMDBMigrationManager linked to your database
      • Create a version table with FMDBMigrationManager
      • As your apps release, new migrations are need
      • New migrate objects that confirm FMDBMigrating
        • Implement methods in the protocol
        • Version and progress closure is the most important part
        • Which determine the order of migrations and what will be done
      • Migrate to latest version 
        //create manager
FMDBMigrationManager *manager = [FMDBMigrationManager managerWithDatabaseAtPath:@"path/to/your/DB.sqlite" migrationsBundle:[NSBundle mainBundle]];
//create table, check existed before create
BOOL success = [manager createMigrationsTable:&error];
//New objects confirm to FMDBMigrating
//Add to manager
[manager addMigrations:[#yourMigrations]]
//migrate
BOOL success = [manager migrateDatabaseToVersion:UINT64_MAX progress:nil error:&error];
      • As your app continue releases, just new FMDBMigrating objects and add them to manager