sqlite系列(2)使用FMDB保存数据swift

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1.创建一个数据库的工具类

import UIKitimport FMDBclass XBDataManger: NSObject {    //单例    static let shareInstance : XBDataManger = XBDataManger()    //创建一个队列(线程安全的队列)    var queue : FMDatabaseQueue?        var db : FMDatabase?

     //打开数据库

    func openDB()    {        let path = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true).last!        let filePath = (path as NSString).stringByAppendingPathComponent("status.db")               //print(filePath)                        queue = FMDatabaseQueue(path: filePath)        //创建表                        createTable()    }    private func createTable(){        let sql = "CREATE TABLE 'T_status' ( 'status' text,'statusid' integer NOT NULL,'userid' integer,PRIMARY KEY('statusid'))"        queue?.inDatabase({ (db) -> Void in            //执行代码            db.executeUpdate(sql, withArgumentsInArray: nil)        })            }    }

2.保存数据的接口

    func saveData(array : [[String : NSObject]])    {        let sql = "insert into T_status (statusId,status,userId) VALUES (?,?,?)"                //遍历去取得数据        for dic in array        {            let statusId = dic["idstr"]                        //把字典转换为字符串   先转换成data通过<span style="font-family: Arial, Helvetica, sans-serif;">NSJSONSerialization.dataWithJSONObject</span><span style="font-family: Arial, Helvetica, sans-serif;">来实现</span>            let data = try! NSJSONSerialization.dataWithJSONObject(dic, options: NSJSONWritingOptions(rawValue: 0))            let str = NSString(data: data, encoding: NSUTF8StringEncoding)                                    //插入数据  支持事务            XBDataManger.shareInstance.queue?.inTransaction({ (db, rollback) -> Void in               if db.executeUpdate(sql, withArgumentsInArray: [statusId!,str!,XBUserViewModel.shareInstance.usermodel!.uid!])               {                print("插入成功!")                }               else {                print("插入失败!")                }            })                    }                    }

3.加载数据库中数据

主要步骤：拼接sql 执行sql 遍历结果集合字典转模型

    func loadCacheStatus(since_id : Int,max_id : Int,finish : ([[String : NSObject]])->())    {        //根据sinceId he max_id 来进行 sql语句的拼接        var sql = "SELECT statusId,status FROM T_status \n" +        "WHERE userId = '\(XBUserViewModel.shareInstance.usermodel!.uid!)'\n"                if(since_id > 0)        {            sql += "AND statusId > \(since_id) \n"        }        else if(max_id > 0)        {            sql += "AND statusId < \(since_id) \n"        }                sql += "ORDER BY statusId DESC LIMIT 20"                //print(sql)        //查询操作        XBDataManger.shareInstance.queue?.inTransaction({ (db, _) -> Void in            let result = db.executeQuery(sql, withArgumentsInArray: nil)            var array = [[String : NSObject]]()            while result.next()            {                let str = result.stringForColumn("status")                //通过字符串来转换成字典                  let data = str.dataUsingEncoding(NSUTF8StringEncoding)                                //转换成字典                let dic = try! NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions(rawValue: 0))                array.append(dic as! [String : NSObject])                            }            //完成回调            finish(array)        })    }

4. 去网络加载数据接口

    func loadData(since_id : Int = 0,max_id : Int = 0,success : (count : Int)->(),fail : (error : NSError)->())    {

<span style="white-space:pre"></span>//先去数据库加载，然后再去网络中加载数据         self.loadCacheStatus(since_id, max_id: max_id) { (dataArray) -> () in

<span style="white-space:pre"></span>                if dataArray.count > 0            {                //遍历字典转模型                 for dic in dataArray                {                   let statu = XBStatus(dic: dic)                    self.StatusArray?.append(statu)                }

                success(count: -1)            }            else            {                //去网络上加载数据            }        }    }

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