swift - 如何检索满足条件 swift 2 的 CoreData

Question

我有一个包含如下字段的数据库

纬度经度标志 54.1425 98.2564 0 52.1036 94.1458 3 51.1569 92.1458 3 50.1326 91.1458 3 56.1236 93.1458 0

我需要检索标记为 3 的记录。

    let fetchRequest = NSFetchRequest()

    let appDelegate =
    UIApplication.sharedApplication().delegate as! AppDelegate
    let managedContext = appDelegate.managedObjectContext

    let entityDescription = NSEntityDescription.entityForName("TABLE_LOCATION", inManagedObjectContext: managedContext)




    // Configure Fetch Request
    fetchRequest.entity = entityDescription


    do {
        let result = try managedContext.executeFetchRequest(fetchRequest)
        //print(result)


    } catch {
        let fetchError = error as NSError
        print(fetchError)
    }

我所拥有的只是上面的代码，它从表 TABLE_LOCATION 中检索所有记录，非常感谢任何代码或工作示例

谢谢!

Answer 1

您需要将 NSPredicate 添加到您的 fetchRequest。

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSPredicate_Class/

fetchRequest.predicate = NSPredicate(format: "flag == %@", "3")