java - RuntimeException - java.lang.IllegalArgumentException : column '_id' does not exist

Question

在我的应用程序中，我尝试从数据库中的表中读取数据，该表的创建方式如下:

public DBHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
    String createDreamTable = String.format("CREATE TABLE IF NOT EXISTS %s" +
            "( %s INTEGER PRIMARY KEY AUTOINCREMENT, " +
            "%s VARCHAR, " +
            "%s TEXT);",
            DreamContract.Dream.DREAM_TABLE_NAME,
            DreamContract.Dream._ID,
            DreamContract.Dream.COLUMN_NAME_DREAM_TITLE,
            DreamContract.Dream.COLUMN_NAME_DREAM_CONTENT);
    Log.d("avirankatz", createDreamTable);
    db.execSQL(createDreamTable);
}

当我尝试使用 GetDreamTitles 从数据库获取数据时，如下所示，我得到 java.lang.IllegalArgumentException: column '_id' does not exist

public Cursor getDreamTitles() {
    return getReadableDatabase().rawQuery(String.format("SELECT %s FROM %s", DreamContract.Dream.COLUMN_NAME_DREAM_TITLE, DreamContract.Dream.DREAM_TABLE_NAME), null);
}

编辑:

DreamContract.Dream :

public static abstract class Dream implements BaseColumns {
    public static final String DREAM_TABLE_NAME = "dreamDiary";
    public static final String COLUMN_NAME_DREAM_TITLE = "title";
    public static final String COLUMN_NAME_DREAM_CONTENT = "dreamContent";
}

Answer 1

在查询中添加主键 _id，如下所示

getReadableDatabase().rawQuery(
    String.format(
        "SELECT %s, %s FROM %s", 
        DreamContract.Dream._ID, 
        DreamContract.Dream.COLUMN_NAME_DREAM_TITLE, 
        DreamContract.Dream.DREAM_TABLE_NAME
    ), 
    null
);