Table not found after adding preloaded sqlite db to iOS App using Xcode

Question

I have a preloaded SQLite database, named "myDB.dms". I want to package the DB and access the contents from within the app.

So to that first, I dragged and dropped the DB file in my Xcode ProjectNavigator window and on a prompt I click on "Copy files if needed".

I use FMDB library to access the SQLite DB.

I created a new Database interface class and added 3 different methods:

1. openDB
2. copyDB
3. executeQuery

Because while packaging the DB file will in Bundle resource folder, I had to copy the files from resource folder to directory folder as below:

func copyDB() -> Bool {
    let fileManager = FileManager.default
    let documentsUrl = fileManager.urls(for: .documentDirectory, in: .userDomainMask)
    var returnStatus: Bool = false

    guard documentsUrl.count != 0 else {
        print("Could not find documents url")
        return false
    }

    let finalDatabaseURL = documentsUrl.first!.appendingPathComponent(dbFileName)

    if !((try? finalDatabaseURL.checkResourceIsReachable()) ?? false) {
        print("DB does not exist in documents folder")

        let documentsURL = Bundle.main.resourceURL?.appendingPathComponent(dbFileName)

        do {
            try fileManager.copyItem(atPath: (documentsURL?.path)!, toPath: finalDatabaseURL.path)
        } catch let error as NSError {
            print ("Couldnt copy file to final location! Error:\(error.description)")
            returnStatus = false
        }
    } else {
        print ("Database file found at path: \(finalDatabaseURL.path)")
        returnStatus = true
    }

    return returnStatus
}

Below is the code to OpenDatabase

func openDB() -> Bool {
    let fileManager = FileManager.default
    let documentsUrl = fileManager.urls(for: .documentDirectory, in: .userDomainMask)
    let dbPath = documentsUrl.first!.appendingPathComponent(dbFileName)
    let database = FMDatabase(url: dbPath)

    var returnStatus: Bool = false

    if (self.copyDB() == false) {
        returnStatus = false
    } else {
        if (!database.open(withFlags: 1)) {
            print("Could not open database at \(dbPath.absoluteString)")
            returnStatus = false
        } else {
            self.database = database
            returnStatus = true
        }
    }

    return returnStatus
}

and below is the code for executing a query

func executeQuery(queryString:String) {
    print(queryString)
    do {
        if (database.open()){
            let results:FMResultSet = try database.executeQuery(queryString, values: nil)

            if results.next() == true {
                print(results)
            }
        }
    } catch let error as NSError {
        print(error.description)
    }
}

The copyDB() and openDB() works fine, but then I try to executeQuery(), I get below error:

Error Domain=FMDatabase Code=1 "no such table: tableName" UserInfo={NSLocalizedDescription=no such table: tableName}

Answer 1

Below is the code which worked:

    func copyDataBase() -> Bool {
    let fileManager = FileManager.default
    var dbPath = ""

    do {
        dbPath = try fileManager.url(for: .applicationSupportDirectory, in: .userDomainMask, appropriateFor: nil, create: true).appendingPathComponent(dbFileName).path
    } catch {
        print(error.localizedDescription)
        return false
    }

    if !fileManager.fileExists(atPath: dbPath) {
        let dbResourcePath = Bundle.main.path(forResource: "dbName", ofType: "sqlite")
        do {
            try fileManager.copyItem(atPath: dbResourcePath!, toPath: dbPath)
        } catch {
            print(error.localizedDescription)
            return false
        }
    }
    return true
}

I hope this will help somebody in need