class DataManager: NSObject {

//定義一個單例對象（類對象）
//系統(tǒng)中shareManager泣特、defaultManager逾柿、standerdManager這一類獲取的對象一般都是單例對象
static let shareManager = DataManager()

//定義管理數(shù)據(jù)庫的對象
let fmdb:FMDatabase!

//線程鎖,通過加鎖和解鎖來保證所做操作數(shù)據(jù)的安全性
let lock = NSLock()

//1.重寫父類的構造方法
override init() {
    //設置數(shù)據(jù)庫的路徑;fmdb.sqlite是由自己隨意命名
    let path = NSHomeDirectory().stringByAppendingString("/Documents/fmdb.sqlite")
    //構造管理數(shù)據(jù)庫的對象
    fmdb = FMDatabase(path: path)
    //判斷數(shù)據(jù)庫是否打開成功;如果打開失敗則需要創(chuàng)建數(shù)據(jù)庫
    if !fmdb.open() {
        print("數(shù)據(jù)庫打開失敗")
        return
    }
    //創(chuàng)建數(shù)據(jù)庫
    //student表達表名掐暮，由自己命名
    //userName,passWord是需要收藏的模型中的字段泉瞻，須根模型中保持一致
    //varchar表示字符串祭示，integer表示數(shù)字拍冠，blob表示二進制數(shù)據(jù)NSData
    let createSql = "create table if not exists student(userName varchar(1024),passWord varchar(1024))"
    
    //執(zhí)行sel語句進行數(shù)據(jù)庫的創(chuàng)建
    do {
        try fmdb.executeUpdate(createSql, values: nil)
    }catch {
        print(fmdb.lastErrorMessage())
    }
}

//2.增
func insertDataWith(model:StudentModel) {

    //加鎖操作
    lock.lock()
    //sel語句
    //(?,?)表示需要傳的值贴妻，對應前面出現(xiàn)幾個字段，后面就有幾個問號
    let insetSql = "insert into student(userName, passWord) values(?,?)"
    //更新數(shù)據(jù)庫
    do {
        try fmdb.executeUpdate(insetSql, values: [model.userName!,model.passWord!])
    }catch {
        print(fmdb.lastErrorMessage())
    }
    
    //解鎖
    lock.unlock()
}

//3.刪
func deleteDataWith(model:StudentModel) {

    //加鎖操作
    lock.lock()
    //sel語句
    //where表示需要刪除的對象的索引只磷，是對應的條件
    let deleteSql = "delete from student where userName = ?"
    //更新數(shù)據(jù)庫
    do{
        try fmdb.executeUpdate(deleteSql, values: [model.userName!])
    }catch {
        print(fmdb.lastErrorMessage())
    }
    
    //解鎖
    lock.unlock()
}

//4.改
func updateDataWith(model:StudentModel,daraID:String) {

    //加鎖
    lock.lock()
    //where id = ?中的id可傳可不傳
    let updateSql = "update student set userName = ?,passWord = ? where id = ?"
    //更新數(shù)據(jù)庫
    do{
        try fmdb.executeUpdate(updateSql, values: [model.userName!,model.passWord!])
    }catch {
        print(fmdb.lastErrorMessage())
    }
    
    //解鎖
    lock.unlock()
}

//5.判斷數(shù)據(jù)庫中是否有當前數(shù)據(jù)(查找一條數(shù)據(jù))
func isHasDataInTable(model:StudentModel) -> Bool {

    let isHas = "select * from student where userName = ?"
    do{
        let set = try fmdb.executeQuery(isHas, values: [model.userName!])
        //查找當前行经磅，如果數(shù)據(jù)存在，則接著查找下一行
        if set.next() {
            return true
        }else {
            return false
        }
    }catch {
        print(fmdb.lastErrorMessage())
    }

    return true
}

//6.查找全部數(shù)據(jù)
func fetchAllData() ->[StudentModel] {

    let fetchSql = "select * from student"
    //用于承接所有數(shù)據(jù)的臨時數(shù)組
    var tempArray = [StudentModel]()
    do {
        let set = try fmdb.executeQuery(fetchSql, values: nil)
        //循環(huán)遍歷結果
        while set.next() {
            let model = StudentModel()
            //給字段賦值
            model.userName = set.stringForColumn("userName")
            model.passWord = set.stringForColumn("passWord")
            tempArray.append(model)
        }
    }catch {
        print(fmdb.lastErrorMessage())
    }
    
    return tempArray
  }
}