This is a common problem I’ve seen since Room was announced. Room does not support the ability to store Lists directly, nor the ability to convert to/from Lists. It supports converting and storing POJO’s. In this case the solution is simple. Instead of storing a List<CountryLang> you want to store CountryLangs (note the ‘s’) I’ve … Read more
You can just concat using SQLite string concatenation. @Query(“SELECT * FROM hamster WHERE name LIKE ‘%’ || :search || ‘%'”) fun loadHamsters(search: String?): Flowable<List<Hamster>>
Based on the documentation here (below the code snippet) A method annotated with the @Insert annotation can return: long for single insert operation long[] or Long[] or List<Long> for multiple insert operations void if you don’t care about the inserted id(s)
You can easly insert the class with list object field using TypeConverter and GSON, public class DataConverter { @TypeConverter public String fromCountryLangList(List<CountryLang> countryLang) { if (countryLang == null) { return (null); } Gson gson = new Gson(); Type type = new TypeToken<List<CountryLang>>() {}.getType(); String json = gson.toJson(countryLang, type); return json; } @TypeConverter public List<CountryLang> toCountryLangList(String … Read more
It’s not a problem in your case, but for others, this error can occur if you have @Ignore params in your primary constructor, i.e. Room expects to have either: parameterless constructor or constructor with all fields not marked with @Ignore for example: @Entity(tableName = “movies”) data class MovieKt( @PrimaryKey var id : Int, var title: … Read more
You can do this by changing your Dao from an interface to an abstract class. @Dao public abstract class UserDao { public void insertPetsForUser(User user, List<Pet> pets){ for(Pet pet : pets){ pet.setUserId(user.getId()); } _insertAll(pets); } @Insert abstract void _insertAll(List<Pet> pets); //this could go in a PetDao instead… @Insert public abstract void insertUser(User user); @Query(“SELECT * … Read more
For those working with Kotlin, try changing annotationProcessor to kapt in the apps build.gradle for example: // Extensions = ViewModel + LiveData implementation “android.arch.lifecycle:extensions:1.1.0” kapt “android.arch.lifecycle:compiler:1.1.0” // Room implementation “android.arch.persistence.room:runtime:1.0.0” kapt “android.arch.persistence.room:compiler:1.0.0” also remember to add this plugin apply plugin: ‘kotlin-kapt’ to the top of the app level build.gradle file and do a clean and … Read more
Type Converter are made specifically for that. In your case, you can use code snippet given below to store data in DB. public class Converters { @TypeConverter public static ArrayList<String> fromString(String value) { Type listType = new TypeToken<ArrayList<String>>() {}.getType(); return new Gson().fromJson(value, listType); } @TypeConverter public static String fromArrayList(ArrayList<String> list) { Gson gson = new … Read more
I had a similar issue. Here is my solution. You can use an extra entity (ReservationGuest) which keeps the relation between Guest and Reservation. @Entity data class Guest( @PrimaryKey val id: Long, val name: String, val email: String ) @Entity data class Reservation( @PrimaryKey val id: Long, val table: String ) @Entity data class ReservationGuest( … Read more
Document is really confusing. Try with just below classes: 1) User Entity: @Entity public class User { @PrimaryKey public int id; // User id } 2) Pet Entity: @Entity public class Pet { @PrimaryKey public int id; // Pet id public int userId; // User id public String name; } 3) UserWithPets POJO: // Note: … Read more