使用NSPredicate查詢CloudKit以獲取空白日期（或null或其他）

Question

我想查詢CloudKit以獲取具有空白日期（0/00/0000 00:00:00）的所有記錄，並且我不知道如何創建將執行此操作的謂詞。

這是我嘗試過的，以及相關的錯誤：

    let predicate = NSPredicate(format: "ready == nil")                     // <ready != nil>: <nil> is not a function expression
    let predicate = NSPredicate(format: "ready == NIL")                     // <ready == nil>: <nil> is not a function expression
    let predicate = NSPredicate(format: "ready != NULL")                        // <ready != nil>: <nil> is not a function expression
    let predicate = NSPredicate(format: "ready == %@", NSNull())            // NSNull not allowed in comparison expression
    let predicate = NSPredicate(format: "ready == $NULL")                   // Unable to parse the format string "ready == $NULL"
    let predicate = NSPredicate(format: "ready == $BLANK")                  // <ready == $BLANK>: <$BLANK> is not a function expression
    let blankDate: Date = Date.init()
    let predicate = NSPredicate(format: "ready == %@", blankDate as NSDate)

    let haveADate = NSPredicate(format: "ready > %@", NSDate.distantPast as NSDate)
    let predicate = NSCompoundPredicate(notPredicateWithSubpredicate: haveADate)    // Inverting a valid one doesn't work either

Answer 1

我相信你的問題與此類似。

而不是"ready == %@" ，你應該嘗試使用"(ready >= %@) AND (ready <= %@)"與兩個參考值進行比較。