How to dynamically query the room database at runtime?

Question

The problem

Is it possible construct a query at runtime?

Use case

@Query(\"SELECT * FROM playlist \" +
        \"WHERE play         


        

Answer 1

Use SupportSQLiteQuery.

https://developer.android.com/reference/android/arch/persistence/db/SupportSQLiteQuery

Latest release 1.1.1 now uses SupportSQLiteQuery.

A query with typed bindings. It is better to use this API instead of rawQuery(String, String[]) because it allows binding type safe parameters.

@Dao
     interface RawDao {
         @RawQuery(observedEntities = User.class)
         LiveData> getUsers(SupportSQLiteQuery query);
     }

Usage:

     LiveData> liveUsers = rawDao.getUsers( new 
SimpleSQLiteQuery("SELECT * FROM User ORDER BY name DESC"));

Update your gradle to 1.1.1

implementation 'android.arch.persistence.room:runtime:1.1.1'
implementation 'android.arch.lifecycle:extensions:1.1.1'
annotationProcessor "android.arch.persistence.room:compiler:1.1.1"

Note: if you upgrade to 1.1.1, and are using String instead of SupportSQLiteQuery,

you will get the error:

RawQuery does not allow passing a string anymore. Please use android.arch.persistence.db.SupportSQLiteQuery.

Using SupportSQLiteQuery as above will solve the problem.

Note: Make sure you pass in SupportSQLiteQuery query parameter or you will get this error:

RawQuery methods should have 1 and only 1 parameter with type String or SupportSQLiteQuery