sqlite数据库的一些操作和core data的操作

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应用程序接口的解释

http://www.xuebuyuan.com/321813.html

打开数据库的一些操作

sqlite3_open

创建数据库表

sqlite3_exec

关闭数据库 sqlite3_close

if sqlite3_open(path, &db) != SQLITE_OK {            print("error")        }        //创建表的过程        let string = "CREATE TABLE IF NOT EXISTS PERSONINFO (ID INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER, address TEXT)";        let cString = string.cStringUsingEncoding(NSUTF8StringEncoding)        if(sqlite3_exec(db, cString!, nil, nil, nil) != SQLITE_OK) {            print("失败")        }        sqlite3_close(db)

查询数据的过程

sqlite3_open打开数据库

sqlite3_prepare_v2函数预处理sql语句转化成二进制代码更高速的执行

sqlite3_step执行sql语句，遍历结果集

sqlite3_column_text函数提取字段的数据

sqlite3_finalize或者sqlite3_close释放资源

 var cpath = document!.stringByAppendingPathComponent("personinfo.sqlite")         if sqlite3_open(cpath, &db) != SQLITE_OK{            print("error")         }else {            var statement = COpaquePointer()            //查询的sql语句 ?代表要绑定的参数            let sql = "SELECT cdate,content FROM Note where cdate = ?"            let csql = sql.cStringUsingEncoding(NSUTF8StringEncoding)            //预处理sql语句 将sql编译成二进制代码 提高sql语句的执行速度 第三个参数代表全部sql字符串的长度 第4个参数是地址 是语句对象 通过语句对象可以执行sql语句 第5个参数是sql语句没有执行的部分语句            if sqlite3_prepare_v2(db, csql!, -1, &statement, nil) == SQLITE_OK{                let dateFormetter = NSDateFormatter()                dateFormetter.dateFormat = "yyyy-MM-dd HH:mm:ss"                var strDate = "string"                let cDate = strDate.cStringUsingEncoding(NSUTF8StringEncoding)             //绑定参数 第一个参数是statement指针 第二个参数为序号 从1开始 第3个参数是字符串的值  第4个参数为字符串的长度 第5个参数是函数指针            sqlite3_bind_text(statement, 1, cDate!, -1, nil)                //执行 若返回值是SQLITE_ROW 代表还有其他的行没有遍历                sqlite3_step(statement)            }

修改数据的过程

sqlite3_open打开数据库

sqlite3_prepare_v2函数预处理sql语句

sqlite3_bind_text绑定参数

sqlite3_step执行语句

sqlite3_finalize或者sqlite3_close关闭数据库

以下是插入的一些操作还有一点错误以后改正

 //插入数据的过程let insert1 = "INSERT INTO personinfo (name,age,address) VALUES ('caokaiqiang', '14', 'zhejiang')"        if sqlite3_exec(db, insert1.cStringUsingEncoding(NSUTF8StringEncoding)!, nil, nil, nil) != SQLITE_OK{            print("error")        }

通过core data来创建数据主要通过上下文的context来进行数据的插入删除还有查询注意查询的时候返回的是一对数组为[NSManagedObject] 所以可以用valueForKey来提取

import UIKitimport CoreDataclass ViewController: UIViewController,UITableViewDataSource {    var managedContext:NSManagedObjectContext!    var people = [NSManagedObject]()    @IBOutlet weak var tableView: UITableView!    override func viewDidLoad() {        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.        title = "\"The List\""      tableView.registerClass(UITableViewCell.self, forCellReuseIdentifier: "Cell")        let image = UIImage(named: "1")        let photoData = UIImagePNGRepresentation(image!)    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }//实现数据源    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {        return people.count    }    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {        let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)        let person = people[indexPath.row]        cell.textLabel?.text = person.valueForKey("name") as? String        return cell    }    @IBAction func addName(sender: UIBarButtonItem) {    let alert = UIAlertController(title: "New Name", message: "addNewName", preferredStyle: .Alert)        let alertAction = UIAlertAction(title: "addNewName", style: .Default) { (action:UIAlertAction) -> Void in            let textField = alert.textFields![0] as UITextField            self.saveName(textField.text!)            self.tableView.reloadData()        }    alert.addTextFieldWithConfigurationHandler(nil)        let cancelAction = UIAlertAction(title: "Cancel", style: .Default, handler: nil)    alert.addAction(alertAction)    alert.addAction(cancelAction)        self.presentViewController(alert, animated: true, completion: nil)    }    func saveName(name:String) {        let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate        //托管对象文本认为是在内存中暂存的管理对象        let managedContext = appDelegate.managedObjectContext        let entity = NSEntityDescription.entityForName("Person", inManagedObjectContext: managedContext)        let person = NSManagedObject(entity: entity!, insertIntoManagedObjectContext: managedContext)        person.setValue(name, forKey: "name")        do { try managedContext.save()        }catch{            print("error")        }        people.append(person)    }    //读取数据    override func viewWillAppear(animated: Bool) {        //托管对象文本认为是在内存中暂存的管理对象        var fetchedResults = [NSManagedObject]()              let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate        let managedContext = appDelegate.managedObjectContext        //读取数据的类 是一个修饰语                     let fetchRequest = NSFetchRequest(entityName: "Person")                     //处理请求        do { fetchedResults =  try managedContext.executeFetchRequest(fetchRequest) as! [NSManagedObject]        }catch{            print("error")        }      people = fetchedResults    }}

通过fetchResultController 将core data和tableview联系起来

import UIKitimport CoreDataclass ViewController: UIViewController,UITableViewDataSource {        @IBOutlet weak var tableView: UITableView!    var managedContext:NSManagedObjectContext!    var fetchedResultsController:NSFetchedResultsController!    override func viewDidLoad() {         var app = UIApplication.sharedApplication().delegate as! AppDelegate        self.managedContext = app.managedObjectContext        super.viewDidLoad()        // Do any additional setup after loading the view, typically from a nib.    //创建fetch request        let entity = NSEntityDescription.entityForName("Team", inManagedObjectContext: managedContext)        let team = Team(entity: entity!, insertIntoManagedObjectContext: managedContext)        team.teamName = "cao"        managedContext.performBlock { () -> Void in            do { try  self.managedContext.save()            }catch{                print("error")            }             let sort = NSSortDescriptor(key: "teamName", ascending: true)        let fetchRequest = NSFetchRequest(entityName: "Team")        fetchRequest.sortDescriptors = [sort]        //创建controller         self.fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.managedContext, sectionNameKeyPath: nil, cacheName: nil)        do { try self.fetchedResultsController.performFetch()        }catch{            print("加载失败")        }    }    }    override func didReceiveMemoryWarning() {        super.didReceiveMemoryWarning()        // Dispose of any resources that can be recreated.    }    func numberOfSectionsInTableView(tableView: UITableView) -> Int {        return (fetchedResultsController.sections?.count)!    }    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {        let sectionInfo = fetchedResultsController.sections as! NSFetchedResultsSectionInfo        return sectionInfo.numberOfObjects    }    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {        let sectionInfo = fetchedResultsController.sections as! NSFetchedResultsSectionInfo               let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath)        var info = sectionInfo.objects as! [NSManagedObject]        let team = info[indexPath.row]         cell.textLabel?.text = team.valueForKey("teamName") as! String        return cell

最好可以用异步添加的方法来初始化fetchedRequest这样可以避免阻塞主线程可以在context中使用多线程较好的博客有在异步线程的操作里面跟新UI

http://www.jianshu.com/p/37ab8f336f76

  var manaCtx = NSManagedObjectContext(concurrencyType: .PrivateQueueConcurrencyType)

        //用异步加载的方法 个人认为更好        asycFetch = NSAsynchronousFetchRequest(fetchRequest: fetch, completionBlock: { (result) -> Void in        self.people = result.finalResult as! [NSManagedObject]                       }            )        do {  let a = try manaCtx.executeRequest(asycFetch!)        }catch{            print(error)    }

        fetchedResultController = NSFetchedResultsController(fetchRequest: fetchReq, managedObjectContext: manaCtx, sectionNameKeyPath: nil , cacheName: nil)        //执行加载的操作        do { try fetchedResultController?.performFetch()        }catch{            print("error")        }            }    func numberOfSectionsInTableView(tableView: UITableView) -> Int {           return (fetchedResultController?.sections?.count)!    }    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {      let sectionInfo = (fetchedResultController?.sections![section])! as NSFetchedResultsSectionInfo        return sectionInfo.numberOfObjects    }    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {        let cell = tableView.dequeueReusableCellWithIdentifier("cell")        var object = fetchedResultController?.objectAtIndexPath(indexPath)        cell?.textLabel?.text = object?.valueForKey("cao")?.description     return cell!    }

比较好的博客

http://blog.csdn.net/yamingwu/article/details/42435083

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