前言

上一篇很高興已經使用SQLite.swift來儲存
但回傳的數值竟然報錯
經過多次的測試
以及重裝APP發現
回傳數值並不是我存入的類型
而是返回Binding?類型
這類型我竟然沒辦法使用as 來變換型態
也不能使用Int(變數)來改變
那今天我就來debug這個問題吧

SQLite目前

目前進度將原先
寫死的SQLite.swift 語法
改為活得 SQL語法帶入

舊Func

可以直接使用dic的key下去儲存在model

func reloadDataOlder(tableName:String) {
    productList = [ProductItemtMode]()
    let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
    let db = try? Connection("\(path)/Chuhuo.sqlite")
    users = Table(tableName)
    for user  in (try? db?.prepare(users))!! {
        let currentDate = user[date]
        let dataFormatter = DateFormatter()
        dataFormatter.locale = Locale(identifier: "zh_Hant_TW")
        dataFormatter.dateFormat = "YYYY年MM月dd日"
        let stringDate = dataFormatter.string(from: currentDate)
        print(stringDate)

        let productItemMode = ProductItemtMode()
        productItemMode.price = user[price]
        productItemMode.product = user[product]
        productItemMode.date = user[date]
        productItemMode.amount = user[amount]
        productList.append(productItemMode)
    }
}

新Func

func reloadData(selectCode:String){
    productList = [ProductItemtMode]()
    let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
    let db = try? Connection("\(path)/Chuhuo.sqlite")
    //"SELECT SUM(price), product, date, amount FROM stock GROUP BY product"
    for user in (try? db?.prepare(selectCode))!! {
        let productItemMode = ProductItemtMode()
        productItemMode.price = user[0] as? Int
        productItemMode.product = user[1] as? Int
        productItemMode.date = user[2] as? Date
        productItemMode.amount = user[3] as? Int
        productList.append(productItemMode)
        print(productList[0].price)
    }
}

照理說應該可以啊 直接as? Int
就可以轉換成Int
但我錯了直接報錯

Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value

Binding Optional沒辦法直接轉換
這裡我找很久 很多中文網站沒有介紹
或是我沒查到
但我在國外網站有找到類似問題
就是SQLite.swift value轉換問題
連結
http://www.devjockeys.com/blog/swift-ios/swift-convert-an-optional-binding-value-to-an-integer-sqlite/

這邊我直接貼程式碼
大概要這樣寫

func reloadData(selectCode:String){
    productList = [ProductItemtMode]()
    let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0]
    let db = try? Connection("\(path)/Chuhuo.sqlite")
    //"SELECT SUM(price), product, date, amount FROM stock GROUP BY product"
    for user in (try? db?.prepare(selectCode))!! {
        let optionalCount : Int64 = Optional(user[0]) as! Int64
        let lCount = Int(optionalCount)
    }
}

重點是這段

let optionalCount : Int64 = Optional(user[0]) as! Int64
let lCount = Int(optionalCount)

要先轉換成Int64再轉Int !?
認真嗎 目前我找到此種方法解
之後有機會 我要再找找最佳解
結束