Question

我尝试查找包含带通配符的子字符串的字符串。在以下示例中，字符串应确认模式 （任何符号＆＃39; *＆＃39;任何符号＆＃39; p＆＃39;任何符号）。我尝试使用此代码从Realm中搜索对象

class ServiceMessage: Object {
  @objc dynamic var desc = ""
}

let realm = try! Realm()

let dataSource = [
    "Domain CheckService",
    "IMEI check",
    "Compliant about service provider",
    "Compliant about TRA",
    "Enquires",
    "Suggestion",
    "SMS* S[pam",
    "Poor Coverage",
    "Pure *Signal",
    "Help Salim"
]

for text in dataSource {
    let sm = ServiceMessage()
    sm.desc = text;
    try! realm.write {
        realm.add(sm)
    }
}


let searchString = "*\\**p*"
let predicate = NSPredicate(format: "SELF.desc LIKE[c] %@", searchString)
let errors = realm.objects(ServiceMessage.self).filter(predicate)

我一无所获。如果我尝试使用此谓词过滤简单的字符串数组，一切正常。有人知道这个问题的解决方案吗？我尝试在 LIKE 后添加[w]它对我没有帮助。

Answer 1

这里的主要问题是你不能在Realm中使用正则表达式作为谓词，因为我们可以在这里阅读https://github.com/realm/realm-cocoa/issues/2629正确的方法应该是

let realmInstance = try? Realm()
let expresion = ".*\\*.*p.*"
let predicate = NSPredicate(format: "SELF.name MATCHES %@", expresion)
self.realmArrayDogs = realmInstance?.objects(Dog.self).filter(predicate)

但会因以下错误而崩溃

由于未捕获的异常而终止应用“无效的运算符类型”，原因：字符串类型'
不支持'运算符'匹配'

这是使用stringArray

的相同示例

let array = ["D*usadpdasd","probando","asdasd*ffffpppp"]
    do{
        let expresion = ".*\\*.*p.*"
        let predicate = NSPredicate(format: "SELF MATCHES %@",expresion)
        let resultArray = array.filter({predicate.evaluate(with: $0)})
        debugPrint(resultArray)
    }
    catch
    {

    }

作为一种解决方法，您可以将结果从Realm转换为Array，然后使用谓词

进行过滤

这有效！

let realmInstance = try? Realm()
let expresion = ".*\\*.*p.*"
let predicate = NSPredicate(format: "SELF.name MATCHES %@", expresion)
let arrayOfDogsResult = realmInstance?.objects(Dog.self)
let filteredArray = Array(arrayOfDogsResult!).filter({predicate.evaluate(with: $0)})
debugPrint(filteredArray)

使用*作为常规字符过滤对象＆＃39; LIKE＆＃39;在境界

1 个答案: