swift简单实用coreData

在开发中经常会涉及到本地数据的存储。一般使用比较多的有，plist，本地文件，SQLite,coredata。根据要存储的数据类型选择对应的方法存储数据。在数据比较复杂时我选用coredata。最初使用原生的SQLite,修改比较麻烦，最后换成了coredata。操作步骤如下：
创建DataModel文件。

image.png

在DataModel中创建数据表，然后在数据表中创建对应的数据字段。

创建一个存储调度器,名字就是上面创建的dataModel文件名

  lazy var persistentContainer: NSPersistentContainer = {
        
        let container = NSPersistentContainer(name: "LocalDataModel")
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
        return container
    }()

  func saveContext () {
        let context = persistentContainer.viewContext
        if context.hasChanges {
            do {
                try context.save()
            } catch {
                
                let nserror = error as NSError
                fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
            }
        }
    }

为了方便操作，我们创建一个类用来添加，删除，修改，查询数据。

import Foundation
import CoreData

let appDelegate = UIApplication.shared.delegate as! AppDelegate
let managedObectContext = appDelegate.persistentContainer.viewContext

class CoreDataManager: NSObject {
    
    //添加数据（添加的数据比较多时，可以使用模型）
    func instertDeviceData(dLatitude:Double,
                           dLongitude:Double,
                           tInspectorName:String,
                           tInspectDateTime:String,
                           tCheckTaskGuid:String,
                           tCheckTaskName:String,
                           tSystemStatus:String,
                           iDeviceCheckStatus:Int16,
                           tDeviceGuid:String,
                           tDeviceName:String,
                           tDeviceCode:String,
                           tDeviceLocation:String,
                           tDeviceDescription:String,
                           tNodeGuid:String,
                           tNodeName:String,
                           tNodeCode:String,
                           iEmptyNodeStatus:Int16,
                           tNodeLocation:String,
                           tNodeDescription:String,
                           isChecked:Int) -> Bool{
        
        let dataModel = NSEntityDescription.insertNewObject(forEntityName: "Inspect_Device_Table", into: managedObectContext) as! Inspect_Device_Table
        
        dataModel.dLatitude                 = dLatitude
        dataModel.dLongitude                = dLongitude
        dataModel.tInspectorName            = tInspectorName
        dataModel.tInspectDateTime          = tInspectDateTime
        dataModel.iIsChecked                = Int16(isChecked)
        
        dataModel.tCheckTaskGuid            = tCheckTaskGuid
        dataModel.tCheckTaskName            = tCheckTaskName
        
        dataModel.tSystemStatus             = tSystemStatus
        dataModel.iDeviceCheckStatus        = iDeviceCheckStatus
        dataModel.tDeviceGuid               = tDeviceGuid
        dataModel.tDeviceName               = tDeviceName
        dataModel.tDeviceCode               = tDeviceCode
        dataModel.tDeviceLocation           = tDeviceLocation
        dataModel.tDeviceDescription        = tDeviceDescription

        dataModel.tNodeGuid                 = tNodeGuid
        dataModel.tNodeName                 = tNodeName
        dataModel.tNodeCode                 = tNodeCode
        dataModel.iEmptyNodeStatus          = iEmptyNodeStatus
        dataModel.tNodeLocation             = tNodeLocation
        dataModel.tNodeDescription          = tNodeDescription
        do {
            try managedObectContext.save()
            print("数据保存成功")
            return true
        }catch{
            print("数据保存失败")
            return false

        }
        
    }
    //查询数据
    func selecteDeviceData(tCheckTaskGuid:String,tDeviceGuid:String,tNodeGuid:String) ->Array<Inspect_Device_Table> {
        var deviceArray = Array<Inspect_Device_Table>()
        //  建立一个获取的请求
        let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Inspect_Device_Table")
        
        //设置查询条件
        if tNodeGuid == "" {
            if tDeviceGuid == "" {
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ ", tCheckTaskGuid)
            }else{
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ and tDeviceGuid=%@", tCheckTaskGuid,tDeviceGuid)
            }
        }else{
            if tDeviceGuid == "" {
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ and tNodeGuid=%@", tCheckTaskGuid,tNodeGuid)
            }else{
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ and tNodeGuid=%@ and tDeviceGuid=%@", tCheckTaskGuid,tNodeGuid,tDeviceGuid)
            }
        }
        // 执行请求  
        do {
            let fetchedResults = try managedObectContext.fetch(fetchRequest) as? [NSManagedObject]
            
            if let results = fetchedResults {

                deviceArray.removeAll()
                for model in results {
                    deviceArray.append(model as! Inspect_Device_Table)
                }
            }
            print("数据读取成功")
            return deviceArray
        } catch  {
            print("数据读取失败")
            return deviceArray
        }
    }
    //删除指定数据
    func deleteDeviceData(tCheckTaskGuid:String,tNodeGuid:String,tDeviceGuid:String) ->Bool {
        //  建立一个获取的请求
        let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Inspect_Device_Table")
        
        if tNodeGuid == "" {
            if tDeviceGuid == "" {
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ ", tCheckTaskGuid)
            }else{
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ and tDeviceGuid=%@", tCheckTaskGuid,tDeviceGuid)
            }
        }else{
            if tDeviceGuid == "" {
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ and tNodeGuid=%@", tCheckTaskGuid,tNodeGuid)
            }else{
                fetchRequest.predicate = NSPredicate(format: "tCheckTaskGuid=%@ and tNodeGuid=%@ and tDeviceGuid=%@", tCheckTaskGuid,tNodeGuid,tDeviceGuid)
            }
        }
        
        let asyncFetchRecquest = NSAsynchronousFetchRequest(fetchRequest: fetchRequest) { (result:NSAsynchronousFetchResult) in
            
            let fetchObjct = result.finalResult as! [Inspect_Device_Table]
            
            for model in fetchObjct{
                managedObectContext.delete(model)
            }
            appDelegate.saveContext()
        }
        do {
            try managedObectContext.execute(asyncFetchRecquest)
            return true
        }catch{
            return false
//            fatalError("删除数据失败")
        }
        
    }


   //删除全部记录
    func deleteAllData() {
       
        let fetchRequestDevice = NSFetchRequest<NSFetchRequestResult>(entityName: "Inspect_Device_Table")
       
        let asyncFetchDeviceRecquest = NSAsynchronousFetchRequest(fetchRequest: fetchRequestDevice) { (result:NSAsynchronousFetchResult) in
            
            let fetchObjct = result.finalResult as! [Inspect_Device_Table]
            
            for model in fetchObjct{
                managedObectContext.delete(model)
            }
            appDelegate.saveContext()
        }
        
        do {
            try managedObectContext.execute(asyncFetchDeviceRecquest)
            
        }catch{
            fatalError("删除数据失败")
        }
    }
}

这是我使用coredata的记录，欢迎交流。