我正在从sqlite中的表中检索数据。我存储为datetime的表存储,日期和值。我想要检索的数据并将其放入两个不同的数组中。一个数组用于日期,另外一个用于数值..数据是动态的...意味着它可以添加更多...
下面是我的代码。
private XYMultipleSeriesDataset getDemoDataset() {
DBHelper helper = new DBHelper(this);
database = helper.getReadableDatabase();
Cursor c = database.rawQuery("select * from " + DBHelper.TABLE_GLUCOSE, null);
//double[] seriesFirstY = {20,-20,67,180,-45,24,99,-34,-8};
double[] seriesSecondY = {10,80,-40,-20,135,24,199,-34,80};
XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
XYSeries firstSeries = new XYSeries("Ideal Reading");
while (!c.isAfterLast()) {
int date = c.getInt((Integer) c.getColumnIndexOrThrow(DBHelper.GLUCOSE_DATE));
int bbData = c.getInt((Integer) c.getColumnIndexOrThrow(DBHelper.BBDATA));
firstSeries.add(bbData, date);
c.moveToNext();
}
dataset.addSeries(firstSeries);
c.close();
/*XYSeries firstSeries = new XYSeries("Ideal Reading");
for (int i = 0; i < myArray.length; i++)
firstSeries.add(i, mStringArray[i]);
dataset.addSeries(firstSeries);*/
XYSeries secondSeries = new XYSeries("Your Reading");
for (int j = 0; j < 9; j++)
secondSeries.add(j, seriesSecondY[j]);
dataset.addSeries(secondSeries);
return dataset;
}
我在
获得了java.lang.nullpointerandroid.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98)
android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98)
android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:158)
答案 0 :(得分:0)
您可以使用动态而不是数组的ArrayList。 如果你真的需要一个数组,那么你可以将ArrayList转换为数组。