Swift Coredata

• 删除关联 Delete Rule

  • Cascade BE2DD438-C4D9-4661-A406-68C9B7D5BBBB.png
  • No Action 3C4C2D1B-1F7F-4707-B1CF-22CB60114EB1.png
  • Deny 4B7AB82F-1289-43C3-A0E2-349DC05001CA.png
  • Nullify 41572FBB-7223-4DFD-88E5-F09BAE35F396.png
• 多表关联 267F7E33-A8CA-4E35-BB92-5BBBBC970541.png
  21D51C83-6626-4F21-B77F-F70DB89FBDB3.png

• 获取上下文

let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

• 存

let entityDes = NSEntityDescription.entity(forEntityName: "Clothes", in: context)
let model = Clothes.init(entity: entityDes!, insertInto: context)
model.name = " aaa"
model.price = Int64(arc4random() % 1000 + 1)
model.ccc = "NN"
dataSrouce.append(model)
try? context.save()

• 删除

context.delete(model)
try? context.save()

• 条件删除

let fetch = NSFetchRequest<NSFetchRequestResult>(entityName: "Clothes")
let pre = NSPredicate(format: "price < %d", 300)
        
fetch.predicate = pre
 let deleArray = try? context.fetch(fetch)
for model in deleArray! {
    context.delete(model as! Clothes)
     dataSrouce.remove(at: dataSrouce.index(of: model as! Clothes)!)
  }
 try? context.save()
 tableView.reloadData()

• 改

let model = dataSrouce[indexPath.row]
model.name = "CC"
model.price = Int64(arc4random() % 10 + 1)
tableView.reloadRows(at: [indexPath], with: .top)
try? context.save()

• 查

  //  查询
let fetch = NSFetchRequest<NSFetchRequestResult>(entityName: "Clothes")
        
 //  排序描述对象
let sortDes = NSSortDescriptor(key: "price", ascending: true)        
fetch.sortDescriptors = [sortDes]        
//  执行查询
//        let result : NSPersistentStoreRequest
  do {
     let result = try context.fetch(fetch)
    for model in result {
       dataSrouce.append((model as! Clothes))
        }
   }catch{
        print(error)
    }

---

• 谓词过滤，排序操作
  • ( >) 、< 、== 、>= 、<= 、!=

let fetch = NSFetchRequest<NSFetchRequestResult>(entityName: "Clothes")
        let pre = NSPredicate(format: "price > %d", 4)
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• Like

let pre = NSPredicate(format: "name like %@","*aaa*")
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• And 也可以写 &&

let pre = NSPredicate(format: "name like %@ and price = 510","*aaa*")
或者let pre = NSPredicate(format: "name like %@ and price = %i","*aaa*",510)
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• Or

let pre = NSPredicate(format: "name like %@ or price = %i","*CC*",554)
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• In

let pre = NSPredicate(format: "name in %@",[" aaa","CC"])
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• Between

let pre = NSPredicate(format: "price between {300,700}")
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• endswith

q 结尾的
let pre = NSPredicate(format: "name endswith[d] 'q'")
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• beginswith

w 开头的
   let pre = NSPredicate(format: "name beginswith[d] 'w'")
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

• contains

let pre = NSPredicate(format: "name contains[d] 'A'")
        fetch.predicate = pre
        let array = try? context.fetch(fetch)
        for model in array! {
            print((model as! Clothes).price)
        }

如果有写错地方请帮我留言! 我是技术渣渣