sqlite嘗試訪問ios時，預填充的數據庫爲空

Question

我對Swift 3和ios相當陌生，以前曾編寫過訪問數據庫的Android程序。 目前的問題是數據庫預填充了10個表，但是，當我嘗試訪問dbase時，無論是在模擬器還是設備中都沒有表，因此無法訪問數據。我搜索了論壇和互聯網，但只能找到信息來檢查數據庫是否存在。 sqlite包裝器是正在使用的FMDB。

代碼：

override func viewDidLoad() { 
    super.viewDidLoad() 
let filemgr = FileManager.default 
let dirPaths = filemgr.urls(for: .documentDirectory, in: .userDomainMask) 

let destPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first! 

databasePath = dirPaths[0].appendingPathComponent("level24.db").path 

print(databasePath) 

let fullDestPath = URL(fileURLWithPath: destPath).appendingPathComponent("level24.db") 

let bundleDatabasePath = Bundle.main.path(forResource: "level24", ofType: ".db") 

var level2DB = FMDatabase(path: databasePath as String) 


    if filemgr.fileExists(atPath: fullDestPath.path){ 
    print("Database file is exist") 
    print(filemgr.fileExists(atPath: bundleDatabasePath!)) 

    }else{ 
    filemgr.replaceItemAt(databasePath, withItemAt: bundleDatabasePath.path) 
    } 



level2DB = FMDatabase(path: databasePath as String) 
if (level2DB?.open())!{ 
      print("Database is open") 

var querySQL = "SELECT * FROM sqlite_master WHERE name = '\(tblName)' and type='table'" 
let results:FMResultSet? = level2DB?.executeQuery(querySQL, withArgumentsIn:nil) 

     if (results == nil){ 
      print("Results = \(results)") 

      do{ 
       try filemgr.copyItem(atPath: bundleDatabasePath!, toPath: fullDestPath.path) 
      }catch{ 
       print("\n",error) 
      } 

     } 
    print("Results after = \(results)") 

    let querySQL2 = "SELECT QUESTION FROM tblSani WHERE _ID = 5" 

    let results2:FMResultSet? = level2DB?.executeQuery(querySQL2, withArgumentsIn:nil) 

    print(results2?.string(forColumn: "QUESTION") as Any) 

    } 
} 

輸出爲：

/Users/***/Library/Developer/CoreSimulator/Devices/4F511422-2F86-49BF-AB10-5CA74B9A7B40/data/Containers/Data/Application/58DD87EB-C20F-4058-B9BC-CCD7ECEEFA98/Documents/level24.db 
Database is open 
Results after = Optional(<FMResultSet: 0x608000245220>) 
2017-04-05 21:09:26.833 Level 2[3161:210849] DB Error: 1 "no such table: tblSani" 
2017-04-05 21:09:26.833 Level 2[3161:210849] DB Query: SELECT QUESTION FROM tblSani WHERE _ID = 5 
2017-04-05 21:09:26.834 Level 2[3161:210849]DBPath: /Users/***/Library/Developer/CoreSimulator/Devices/4F511422-2F86-49BF-AB10-5CA74B9A7B40/data/Containers/Data/Application/58DD87EB-C20F-4058-B9BC-CCD7ECEEFA98/Documents/level24.db 
nil 

，如果你能幫助我找到一個解決問題的方法我們將不勝感激。

Answer 1

在此工作了幾個小時我已經想出了這個解決方案後： 這是投入AppDelegate.swift和將檢查在應用程序的啓動

代碼：

var filemgr = FileManager.default 
static let dirPaths = FileManager().urls(for: .documentDirectory, in: .userDomainMask) 
static let destPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first! 

var databasePath = dirPaths[0].appendingPathComponent("level24.db").path 

static let fullDestPath = URL(fileURLWithPath: destPath).appendingPathComponent("level24.db") 

static let bundleDatabasePath = Bundle.main.path(forResource: "level24", ofType: ".db") 

//function to check if dbase exists 
func checkdbase(){ 

    print(databasePath) 

    print("Full path = \(AppDelegate.fullDestPath)") 

    var level2DB = FMDatabase(path: databasePath as String) 


    if filemgr.fileExists(atPath: AppDelegate.fullDestPath.path){ 

     print("Database file is exist") 
     print(filemgr.fileExists(atPath: AppDelegate.bundleDatabasePath!)) 
     print("bundle = \(AppDelegate.bundleDatabasePath)") 

     let level2DB = FMDatabase(path: databasePath as String) 

     if (level2DB?.open())!{ 
      print("Database is open") 

     // use a select statement for a known table and row 
    let querySQL2 = "SELECT * FROM tblSani WHERE _ID = 5" 

      let results:FMResultSet? = level2DB?.executeQuery(querySQL2, withArgumentsIn:nil) 

       if results?.next()==true{ 
        print("Database has tables") 

       }else{ 
        print("Database no tables") 
        removeDB() 

       } 

     } 
    }else{ 
     removeDB() 
    } 
} 

//function to remove existing dbase then unpack the dbase from the bundle 
func removeDB(){ 

    do{ 
     try filemgr.removeItem(atPath: AppDelegate.fullDestPath.path) 
     print("Database removed") 

    }catch { 
     NSLog("ERROR deleting file: \(AppDelegate.fullDestPath)") 
    } 

    do{ 
     try filemgr.copyItem(atPath: AppDelegate.bundleDatabasePath!, toPath: AppDelegate.fullDestPath.path) 
     print("Databse re-copied") 
    }catch{ 
     print("\n",error) 
    } 

} 

通話從AppDelegate中「didFinishLaunchingWithOptions」

checkdbase() 

如果能夠改善這種應答功能，請做幫助別人誰可能有同樣的問題