Question

在我的应用程序中，我正在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);
}

修改

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

在您的查询中添加主键TypeError: undefined is not an object (evaluating 'newWindow.focus')，如下所示

_id

RuntimeException - java.lang.IllegalArgumentException：列'_id'不存在

1 个答案: