SQLiteException：没有这样的表...在Android中

Question

我一直收到这个错误，我检查了所有内容，但无法找到问题。我试图用一些测试数据填充数据库表，而不是使用这些数据填充微调器。以下是我在活动的onCreate中的代码：

courseSpinner = (Spinner) findViewById(R.id.spinCourse);

    SQLiteHelperCourse courseDbHelper = new SQLiteHelperCourse(this);
    SQLiteDatabase dbw = courseDbHelper.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(CourseEntry.COLUMN_NAME_COURSE_ID, "1");
    values.put(CourseEntry.COLUMN_NAME_COURSE_NAME, "Android");
    values.put(CourseEntry.COLUMN_NAME_CREDITS, "3");
    values.put(CourseEntry.COLUMN_NAME_SEMESTER, "1st");
    values.put(CourseEntry.COLUMN_NAME_YEAR, "3rd");
    dbw.insert(CourseEntry.TABLE_NAME, CourseEntry.COLUMN_NAME_NULLABLE, values);

    SQLiteDatabase dbr = courseDbHelper.getReadableDatabase();
    String[] projection = { CourseEntry.COLUMN_NAME_COURSE_NAME};
    final ArrayList<String> list = new ArrayList<String>();

    Cursor curs = dbr.query(CourseEntry.TABLE_NAME, 
            projection, 
            null, 
            null, 
            null, 
            null, 
            null);
    curs.moveToFirst();

    while(curs.moveToNext())
    {
        list.add(curs.getString(curs.getColumnIndexOrThrow(CourseEntry.COLUMN_NAME_COURSE_NAME)));
    }

    final StableArrayAdapter adapter = new StableArrayAdapter(this,
            android.R.layout.simple_spinner_item, list);

    courseSpinner.setAdapter(adapter);

这是合同类：

public final class CourseContract {

public CourseContract() {}

public static abstract class CourseEntry implements BaseColumns {

    public static final String TABLE_NAME = "courses";
    public static final String COLUMN_NAME_COURSE_ID = "courseid";
    public static final String COLUMN_NAME_COURSE_NAME = "coursename";
    public static final String COLUMN_NAME_YEAR = "year";
    public static final String COLUMN_NAME_SEMESTER = "semester";
    public static final String COLUMN_NAME_CREDITS = "credits";
    public static final String COLUMN_NAME_NULLABLE = "null";

}

}

这是SQLiteHelper类：

public class SQLiteHelperCourse extends SQLiteOpenHelper {

public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "AndroidApplication.db";

public SQLiteHelperCourse(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

private static final String TEXT_TYPE = " TEXT";
private static final String COMMA_SEP = ", ";
private static final String SQL_CREATE_ENTRIES = 
        "CREATE TABLE " + CourseEntry.TABLE_NAME + " (" + CourseEntry._ID + " INTEGER PRIMARY KEY, "
                                                        + CourseEntry.COLUMN_NAME_COURSE_ID + TEXT_TYPE + COMMA_SEP
                                                        + CourseEntry.COLUMN_NAME_COURSE_NAME + TEXT_TYPE + COMMA_SEP
                                                        + CourseEntry.COLUMN_NAME_YEAR + TEXT_TYPE + COMMA_SEP
                                                        + CourseEntry.COLUMN_NAME_SEMESTER + TEXT_TYPE + COMMA_SEP
                                                        + CourseEntry.COLUMN_NAME_CREDITS + TEXT_TYPE + ")";

private static final String SQL_DELETE_ENTRIES = "DROP TABLE IF EXISTS " + CourseEntry.TABLE_NAME;

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL(SQL_CREATE_ENTRIES);

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL(SQL_DELETE_ENTRIES);
    onCreate(db);
}

public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    onUpgrade(db, oldVersion, newVersion);
}
}