领域：如何查询存储在数组中的属性？

Question

所以我有一个带有memberEmails的数组，现在我想查询未存储在这个数组中的用户：

var memberEmails: [String] = // ... is not empty

self.registeredUsers = self.realm.objects(AppUser).filter("email != '\(self.user.email!)' && '\(memberEmails)' !CONTAINS email")

抛出的错误消息：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unable to parse the format string "email != 'iphone5s@mail.com' && '["iphone5s@mail.com"]' !CONTAINS email"'

Answer 1

你不应该使用Swift的字符串插值来进行查询，而是使用NSPredicate的%@格式化程序：

var memberEmails: [String] = // ... is not empty

self.registeredUsers = self.realm.objects(AppUser.self).filter("email != %@ && NOT (email IN %@)", self.user.email, memberEmails)