Question

我试图通过 _id 检索一行数据，并使用我收到的数据创建接种的实例。

public Inoculation retrieveInoculationById(int id) {
  Inoculation inoculation = new Inoculation();
  Cursor cursor = getDataById(InoculationsDao.TABLE_NAME, InoculationsDao.ID, id);
  if (cursor.moveToFirst()) {
    while (!cursor.isAfterLast()) {
      inoculation.setBatchNumber(cursor.getString(cursor.getColumnIndex(InoculationsDao.BATCH_NUMBER)));
      inoculation.setAdministrationSite(cursor.getString(cursor.getColumnIndex(InoculationsDao.ADMINISTRATION_SITE)));
      inoculation.setAdministrationDate(cursor.getString(cursor.getColumnIndex(InoculationsDao.DATE)));
    }
  }
  cursor.close();
  return inoculation;

}

getDataById方法很简单：

public Cursor getDataById(String TABLE_NAME, String ID, int id) {
    Cursor cursor = databaseConnection.rawQuery("SELECT * FROM " + TABLE_NAME + "WHERE " + ID + " = " + id , null);
    return cursor;
}

似乎在rawQuery字符串中失败。

Answer 1

这是因为您的rawQuery字符串错误，因为您错过了空格。

其中：

Cursor cursor = databaseConnection.rawQuery("SELECT * FROM " + TABLE_NAME + "WHERE " + ID + " = " + id , null);

会产生一个查询：

"SELECT * FROM TABLE_NAMEWHERE ID  = id"

应该是：

Cursor cursor = databaseConnection.rawQuery("SELECT * FROM " + TABLE_NAME + " WHERE " + ID + " = " + id , null);

使用rawQuery，您可以使用query()。像这样：

// Your table columns:
private String[] allColumns = { ID, YOUR_OTHER_COLUMN };

Cursor cursor = database.query(TABLE_NAME, allColumns, ID + " = " + id, null,
                                null, null, null);

为什么在从Sqlite DB中通过_id检索对象时会收到SuperNotCalledException？

1 个答案: