const val SQL_CREATE_PERSONS =
            "CREATE TABLE " + "PERSONS" + "(" +
                    "ID" + " TEXT(100) PRIMARY KEY, " +
                    "NAME" + " TEXT(50)
                    "); "

    const val SQL_CREATE_FACES =
            "CREATE TABLE " + "FACES" + "(" +
                    "ID" + " TEXT(100) PRIMARY KEY, " +
                    "PERSON_ID " + "TEXT(100), " +
                    "FOREIGN KEY " + "(PERSON_ID)" + " REFERENCES " +
                    "PERSONS" + "(" +
                    "ID" + ") "+
                    "ON DELETE CASCADE " +
                    "); "
	
override fun onCreate(db: SQLiteDatabase?) {
    db?.execSQL("PRAGMA foreign_keys=ON;")
    db?.execSQL(SQL_CREATE_PERSONS)
    db?.execSQL(SQL_CREATE_FACES)
}