Android Room Pre-packaged database has an invalid schema error

Question

I tried room for the first time and it is not working as expected , and i can't figure out what the problem as i don't have any experience with room. Any help would be really appreciated. I am using prepackaged database , This is the Query i used to create database.

CREATE TABLE quotes_table (
id          INTEGER PRIMARY KEY AUTOINCREMENT,
quote       TEXT    UNIQUE,
category_id TEXT    NOT NULL
);

And this is how i am creating database in my app

Room.databaseBuilder(context.getApplicationContext(),
                        AppDatabase.class, "quotes_database.db")
                        .allowMainThreadQueries()
                        .createFromAsset("database/quotes_database.db")
                        .fallbackToDestructiveMigration()
                        .build();

and this is how i am creating my data class

@Entity(tableName = "quotes_table" ,
    indices = { @Index(value = {"quote"}, unique = true) } )
public class Quote {

@PrimaryKey(autoGenerate = true)
@ColumnInfo(name = "id")
private int id;

@ColumnInfo(name = "quote")
private String quote;

@NonNull
@ColumnInfo(name = "category_id")
private String categoryId;

But my app crashes when i launch the app and here is my logcat

2020-11-17 20:27:14.866 1588-1588/com.example.test E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.test, PID: 1588
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test/com.example.test.MainActivity}: java.lang.IllegalStateException: Pre-packaged database has an invalid schema: quotes_table(com.example.test.Quote).
 Expected:
TableInfo{name='quotes_table', columns={category_id=Column{name='category_id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='INTEGER', affinity='3', notNull=true, primaryKeyPosition=1, defaultValue='null'}, quote=Column{name='quote', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}}, foreignKeys=[], indices=[Index{name='index_quotes_table_quote', unique=true, columns=[quote]}]}
 Found:
TableInfo{name='quotes_table', columns={quote=Column{name='quote', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, category_id=Column{name='category_id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='INTEGER', affinity='3', notNull=false, primaryKeyPosition=1, defaultValue='null'}}, foreignKeys=[], indices=[Index{name='index_quotes_table_quote', unique=true, columns=[quote]}]}
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2817)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2895)
    at android.app.ActivityThread.-wrap11(Unknown Source:0)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1616)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:176)
    at android.app.ActivityThread.main(ActivityThread.java:6651)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)
 Caused by: java.lang.IllegalStateException: Pre-packaged database has an invalid schema: quotes_table(com.example.test.Quote).
 Expected:
TableInfo{name='quotes_table', columns={category_id=Column{name='category_id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='INTEGER', affinity='3', notNull=true, primaryKeyPosition=1, defaultValue='null'}, quote=Column{name='quote', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}}, foreignKeys=[], indices=[Index{name='index_quotes_table_quote', unique=true, columns=[quote]}]}
 Found:
TableInfo{name='quotes_table', columns={quote=Column{name='quote', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}, category_id=Column{name='category_id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='INTEGER', affinity='3', notNull=false, primaryKeyPosition=1, defaultValue='null'}}, foreignKeys=[], indices=[Index{name='index_quotes_table_quote', unique=true, columns=[quote]}]}
    at androidx.room.RoomOpenHelper.onCreate(RoomOpenHelper.java:82)
    at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.onCreate(FrameworkSQLiteOpenHelper.java:118)
    at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:333)
    at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:238)
    at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper$OpenHelper.getWritableSupportDatabase(FrameworkSQLiteOpenHelper.java:92)
    at androidx.sqlite.db.framework.FrameworkSQLiteOpenHelper.getWritableDatabase(FrameworkSQLiteOpenHelper.java:53)
    at androidx.room.SQLiteCopyOpenHelper.getWritableDatabase(SQLiteCopyOpenHelper.java:90)
    at androidx.room.RoomDatabase.inTransaction(RoomDatabase.java:476)
    at androidx.room.RoomDatabase.assertNotSuspendingTransaction(RoomDatabase.java:281)
    at com.example.test.QuoteDao_Impl.getAllQuotes(QuoteDao_Impl.java:63)
2020-11-17 20:27:14.867 1588-1588/com.example.test E/AndroidRuntime:     at com.example.test.MainActivity.onCreate(MainActivity.java:44)
        at android.app.Activity.performCreate(Activity.java:7088)
        at android.app.Activity.performCreate(Activity.java:7079)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2770)
            ... 9 more

I searched a lot on the internet but i couldn't anything that would help me. So any help here would be really appreciated. Thanks

Answer 1

The error message contains the "Expected" schema (what your Room Entity defines) and the "Found" schema - what your pre-packaged database has as its schema. Reordering the columns to match gives you:

 Expected:
TableInfo{name='quotes_table', columns={category_id=Column{name='category_id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='INTEGER', affinity='3', notNull=true,  primaryKeyPosition=1, defaultValue='null'}, quote=Column{name='quote', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}}, foreignKeys=[], indices=[Index{name='index_quotes_table_quote', unique=true, columns=[quote]}]}
 Found:
TableInfo{name='quotes_table', columns={category_id=Column{name='category_id', type='TEXT', affinity='2', notNull=true, primaryKeyPosition=0, defaultValue='null'}, id=Column{name='id', type='INTEGER', affinity='3', notNull=false, primaryKeyPosition=1, defaultValue='null'}, quote=Column{name='quote', type='TEXT', affinity='2', notNull=false, primaryKeyPosition=0, defaultValue='null'}}, foreignKeys=[], indices=[Index{name='index_quotes_table_quote', unique=true, columns=[quote]}]}

These need to match exactly. However, your expected schema has a non-null id column:

id=Column{name='id', type='INTEGER', affinity='3', notNull=true, primaryKeyPosition=1, defaultValue='null'}

But your pre-packaged database has a nullable id column:

id=Column{name='id', type='INTEGER', affinity='3', notNull=false, primaryKeyPosition=1, defaultValue='null'}

You need to change your pre-packaged database to ensure that the id column is NOT NULL .