Use and Access Existing SQLite Database on iOS

Question

I have a fully populated database in SQLite that I\'d like to use in my new app. It\'s rather large, so I\'d like to avoid changing it to another format if possible. How can

Answer 1

Using swift, singleton class and FMDB. you can use below code to achieve it very easily.

Download example

import Foundation
class LocalDatabase: NSObject {


//sharedInstance
static let sharedInstance = LocalDatabase()



    func methodToCreateDatabase() -> NSURL? {

    let fileManager = NSFileManager.defaultManager()

    let urls = fileManager.URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)

    if let documentDirectory:NSURL = urls.first { // No use of as? NSURL because let urls returns array of NSURL

        // exclude cloud backup
        do {
            try documentDirectory.setResourceValue(true, forKey: NSURLIsExcludedFromBackupKey)
        } catch _{
            print("Failed to exclude backup")
        }

        // This is where the database should be in the documents directory
        let finalDatabaseURL = documentDirectory.URLByAppendingPathComponent("contact.db")

        if finalDatabaseURL.checkResourceIsReachableAndReturnError(nil) {
            // The file already exists, so just return the URL
            return finalDatabaseURL
        } else {
            // Copy the initial file from the application bundle to the documents directory
            if let bundleURL = NSBundle.mainBundle().URLForResource("contact", withExtension: "db") {

                do {
                    try fileManager.copyItemAtURL(bundleURL, toURL: finalDatabaseURL)
                } catch _ {
                    print("Couldn't copy file to final location!")
                }

            } else {
                print("Couldn't find initial database in the bundle!")
            }
        }
    } else {
        print("Couldn't get documents directory!")
    }

    return nil
}

    func methodToInsertUpdateDeleteData(strQuery : String) -> Bool
    {

       // print("%@",String(methodToCreateDatabase()!.absoluteString))

        let contactDB = FMDatabase(path: String(methodToCreateDatabase()!.absoluteString) )

        if contactDB.open() {

            let insertSQL = strQuery

            let result = contactDB.executeUpdate(insertSQL,
                withArgumentsInArray: nil)

            if !result {
                print("Failed to add contact")
                print("Error: \(contactDB.lastErrorMessage())")
                return false
            } else {
                print("Contact Added")
                return true
            }
        } else {
            print("Error: \(contactDB.lastErrorMessage())")
            return false
        }

    }

    func methodToSelectData(strQuery : String) -> NSMutableArray
    {

        let arryToReturn : NSMutableArray = []

        print("%@",String(methodToCreateDatabase()!.absoluteString))

        let contactDB = FMDatabase(path: String(methodToCreateDatabase()!.absoluteString) )

        if contactDB.open() {
            let querySQL = strQuery

            let results:FMResultSet? = contactDB.executeQuery(querySQL,
                withArgumentsInArray: nil)

            while results?.next() == true
            {
                arryToReturn.addObject(results!.resultDictionary())
            }

            // NSLog("%@", arryToReturn)

            if arryToReturn.count == 0
            {
                print("Record Not Found")

            }
            else
            {
                print("Record Found")

            }


            contactDB.close()
        } else {
            print("Error: \(contactDB.lastErrorMessage())")
        }

        return arryToReturn

    }
}

Have a happy coding.