1.如果需要使用SQLite，先安装 Cordova-sqlite-storage ，命令行输入

ionic cordova plugin add cordova-sqlite-storage

npm install --save @ionic-native/sqlite

2 在 ./src/app/app.module.ts 中添加

import { IonicStorageModule } from '@ionic/storage';

@NgModule({

  declarations: [...],

  imports: [

    ...,

    IonicStorageModule.forRoot({

      name: 'myApp',

      driverOrder: ['sqlite', 'indexeddb', 'websql']

    })

  ],

  bootstrap: [...],

  entryComponents: [...],

  providers: [...]

})

export class AppModule { }