database - 如何在 react-native 中 realm 数据库检索 nameKey-value？

Question

我需要一个 react native Android/iOS 应用程序的数据库。作为学习 Realm 的第一步，我想用 Realm 替换 AsyncStorage 来读取应用程序设置。

1. 问题:通过 nameKey 访问值的语法是什么？

我的 AppSetting 架构将名称设置为主键:

const AppSetting = {
  name: 'AppSetting',
  primaryKey: 'name',
  schemaVersion: 1,
  properties: {
    name:   {type: 'string'},
    value:   {type: 'string'},
  }
};

如果 appSettings 为空，则我编写 AppSettingsDefault:

const AppSettingsDefault = [
  {
    name: 'version',
    value: '0,'
  },
  {
    name: 'gpsEnabled',
    value: 'true,'
  },
  {
    name: 'unitType',
    value: '2,'
  },
];
console.log('appSettings.length:', appSettings.length);
if(0 >= appSettings.length) {
  console.log("Init default: AppSetting when app is run first time");
  for(let i = 0; i < AppSettingsDefault.length; ++i) {
    let name = AppSettingsDefault[i].name;
    let value = AppSettingsDefault[i].value;
    console.log(name, '=', value);
    realm.write(()=>{
      realm.create('AppSetting', {
        name: name,
        value: value,
      });
    })
  }
}

在 react-native 中检索 'gpsEnabled' 值的 Realm 语法是什么？

let realm = new Realm({schema:
  [AppSetting], schemaVersion: 1});
let appSettings = realm.objects('AppSetting');
// How to retrieve a value by the primary key?
console.log('gpsEnabled', appSettings['gpsEnabled'];  <- This does NOT work

提前感谢任何提示或指导，

Answer 1

试试这个

 let result = realm.objects('AppSetting').filtered('name = "gpsEnabled"');
 let val = result[0].value;

https://realm.io/docs/react-native/latest/#queries