[swift]Core Data新增、更新、查詢、刪除

用來操作 Core Data 的常數

private let coreDataContext = (NSApplication.shared.delegate
as! AppDelegate).persistentContainer.viewContext

取的資料數量：

func getCount() -> Int {
  do{
    let result = try coreDataContext.fetch(Member.fetchRequest())
    for data in result as! [Member] {
      if let name = data.value(forKey: "name") as? String {
        print(name)
      }
    }
    return result.count
  }catch let error as NSError{
    print("getCount->\(error)")
  }
  return 0
}

刪除：

    
    func getCount() -> Int {
        do{
            let result = try coreDataContext.fetch(Member.fetchRequest())
            for data in result as! [Member] {
                if let name = data.value(forKey: "name") as? String {
                    print(name)
                }
                
            }
            return result.count
        }catch let error as NSError{
            print("getCount->\(error)")
        }
        return 0
    }
  
func deleteCoreData(name:String="") -> Bool {
    let request : NSFetchRequest = Member.fetchRequest()
    if name=="" {
        return false
    }
        
    request.predicate = NSPredicate(format: "name = %@",name)

    do{
        let result = try coreDataContext.fetch(request)
        for data in result {
            coreDataContext.delete(data)
        }
        try coreDataContext.save()
        return true
    }catch let error as NSError{
        print("read->\(error)")
        return false
    }
}

新增：

func writeCoreData(name:String) -> Bool {
	let memberEntity = Member(context: coreDataContext)
	memberEntity.id = NSDecimalNumber.init(value: getCount()+1)
	memberEntity.name = name
	memberEntity.createdate = Int(NSDate().timeIntervalSince1970).description

	do{
		try coreDataContext.save()
		return true
	}catch let error as NSError{
		print("read->\(error)")
		return false
	}

}

更新：

func updateCoreData(oldName:String="",newName:String="") -> Bool {
	let request : NSFetchRequest = Member.fetchRequest()
	if oldName=="" || newName==""{
		return false
	}
	// request.predicate = nil
	request.predicate = NSPredicate(format: "name = %@",oldName)

	do{
		let result = try coreDataContext.fetch(request)
		for data in result {
			data.name = newName
			data.createdate = Int(NSDate().timeIntervalSince1970).description
		}
		try coreDataContext.save()
		return true
	}catch let error as NSError{
		print("read->\(error)")
		return false
	}
}

查詢：

func readCoreData(name:String) -> Array<Any> {
	let request : NSFetchRequest = Member.fetchRequest()
	//CONTAINS：查詢特定內容的資料
	request.predicate = NSPredicate(format: "name CONTAINS %@ ",name)

	//BEGINSWITH：查詢特定開頭的資料
	request.predicate = NSPredicate(format: "name BEGINSWITH %@ ",name)

	//ENDSWITH：查詢特定結尾的資料
	request.predicate = NSPredicate(format: "name ENDSWITH %@ ",name)

	//like：查詢特定結尾的資料(以星號的位置決定)
	request.predicate = NSPredicate(format: "name like %@ ","*"+name)

	//like：查詢特定開頭的資料
	request.predicate = NSPredicate(format: "name like %@ ",name+"*")

	//=：查詢內容要跟資料完全一樣
	request.predicate = NSPredicate(format: "name = %@ ",name)

	var arr = Array<Any>()

	do{
		let result = try coreDataContext.fetch(request)
		for data in result {
			let dic = NSMutableDictionary()

			if let name = data.value(forKey: "name") as? String {
				dic.setObject(name, forKey: "name" as NSCopying)
				dic.setObject(data.value(forKey: "createdate") as! String, forKey: "createdate" as NSCopying)
				dic.setObject(data.value(forKey: "id") as! NSDecimalNumber, forKey: "id" as NSCopying)
				// print(name)
			}
			arr.append(dic)
		}
	}catch let error as NSError{
		print("read->\(error)")
	}
	return arr
}