sqlite数据库的一些操作和core data的操作
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 UIKit
import CoreData
class 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 UIKit
import CoreData
class 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