AlterTableMigration to add column throws compile-time error

DBFlow Version: 4.0.4 Issue Kind (Bug, Question, Feature): Question

Description: I have a table that I want to add a column to. I added the column in the Model class and added the below class to my Database class.

`@Migration(version = WizardryDatabase.VERSION, priority = 0, database = WizardryDatabase.class) public class Migration3 extends AlterTableMigration<Bibliography> {

    public Migration3(Class<Bibliography> table) {
        super(table);
    }

    @Override
    public void onPreMigrate() {
        super.onPreMigrate();
        addColumn(SQLiteType.TEXT, "test");
    }
}`

However, I am getting this error when compiling: Error:(18, 21) error: an enclosing instance that contains WizardryDatabase.Migration3 is required

I have incremented the version number in the Database class.

[agrosner]

make the inner class static. it appears you’re making it inner.

[AllanWang]

@strapp342

Thanks a lot. For those who were confused like me, here is my example with Kotlin:

@Database(name = NotificationDb.NAME, version = NotificationDb.VERSION)
object NotificationDb {
    const val NAME = "Notifications"
    const val VERSION = 2
}

@Migration(version = 2, database = NotificationDb::class)
class NotificationMigration2(modelClass: Class<NotificationModel>) : AlterTableMigration<NotificationModel>(modelClass) {
    override fun onPreMigrate() {
        super.onPreMigrate()
        addColumn(SQLiteType.INTEGER, "epochIm")
        L.d("Added column")
    }
}

@Table(database = NotificationDb::class, allFields = true, primaryKeyConflict = ConflictAction.REPLACE)
data class NotificationModel(@PrimaryKey var id: Long = -1L, var epoch: Long = -1L, var epochIm: Long = -1) : BaseModel()

where NotificationModel didn’t have epochIm in version 1.

Make sure to also change the versions, since that was my mistake for the past little while…