Swift NSPredicate，名字和姓氏 NSCompoundPredicate？

Question

在下面的代码中，我使用 NSPredicates，特别是我使用 NSCompoundPredicate 来检查搜索函数中的多个不同参数。我将如何同时使用名字和姓氏进行搜索，我目前正在使用 AND，但它不会在我的 UITableView 中返回任何内容。复合谓词中列出的所有其他谓词都非常有效。

func searchBarSearchButtonClicked(_ searchBar: UISearchBar) {

textInSearchField = searchBar.text!

if searchBar.text == ""{

  print("Searching for all clients.")
  retrieveClients()
  view.endEditing(true)
  clientTableView.reloadData()

}else{

  print("Enter a client name to search.")
  isFilteringSearch = true

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

  let firstAndLast = NSPredicate(format: "firstName = %@ AND lastName = %@", textInSearchField)
  let firstNamePredicate = NSPredicate(format: "firstName = %@", textInSearchField)
  let lastNamePredicate = NSPredicate(format: "lastName = %@", textInSearchField)
  let idPredicate = NSPredicate(format: "id = %@", textInSearchField)
  let orPredicate = NSCompoundPredicate(type: NSCompoundPredicate.LogicalType.or, subpredicates: [firstAndLast,firstNamePredicate, lastNamePredicate, idPredicate])

  clientsEntity.predicate = orPredicate

  clients = try! context.fetch(clientsEntity) as! [NSManagedObject]
  view.endEditing(true)
  clientTableView.reloadData()

}

}

需要记住的是，我仍然需要能够使用LogicalType.or 因为我希望用户可以选择按名字、姓氏以及两者的组合进行搜索，例如 Harold Finch 或 Finch/哈罗德等。

干杯!

Answer 1

let firstAndLast = NSPredicate(format: "firstName = %@ AND lastName = %@", textInSearchField)
let firstNamePredicate = NSPredicate(format: "firstName = %@", textInSearchField)
let lastNamePredicate = NSPredicate(format: "lastName = %@", textInSearchField)
let idPredicate = NSPredicate(format: "id = %@", textInSearchField)

let orPredicate = NSCompoundPredicate(type: NSCompoundPredicate.LogicalType.or, subpredicates: [firstAndLast,firstNamePredicate, lastNamePredicate, idPredicate])

我希望对于orPredicate，它应该是[firstAndLast, idPredicate]，但你没有让它工作。否则您需要重新考虑一下，这就是您的 orPredicate 当前逻辑:

if ((a == x AND b == x) OR (a == x) OR (b == x) OR (c = x)) {
}

(a == x AND b == x) 没有用。

该行有一个问题:

let firstAndLast = NSPredicate(format: "firstName = %@ AND lastName = %@", textInSearchField)

您有两个占位符 (%@)，但只有一个参数 (textInSearchField)。

let firstAndLast = NSPredicate(format: "firstName = %@ AND lastName = %@", textInSearchField, textInSearchField)