Question

当我尝试在SQLite表中添加新行时收到错误，并且在我修复了另一个问题后发生了这个问题。

Logcat表示问题是由某种方法引起的，但我真的不知道我的错误在哪里。

LogCat:
02-28 12:28:45.019: E/AndroidRuntime(432): FATAL EXCEPTION: main
02-28 12:28:45.019: E/AndroidRuntime(432): android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41)
02-28 12:28:45.019: E/AndroidRuntime(432):  at com.androidbook.MP.MP_DB.getMP_Time(MP_DB.java:62)
02-28 12:28:45.019: E/AndroidRuntime(432):  at com.androidbook.MP.MPData.retrieveRecords(MPData.java:77)
02-28 12:28:45.019: E/AndroidRuntime(432):  at com.androidbook.MP.MPData$MyLocationListener.onLocationChanged(MPData.java:181)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.location.LocationManager$ListenerTransport._handleMessage(LocationManager.java:227)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.location.LocationManager$ListenerTransport.access$000(LocationManager.java:160)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.location.LocationManager$ListenerTransport$1.handleMessage(LocationManager.java:176)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.os.Handler.dispatchMessage(Handler.java:99)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.os.Looper.loop(Looper.java:130)
02-28 12:28:45.019: E/AndroidRuntime(432):  at android.app.ActivityThread.main(ActivityThread.java:3683)
02-28 12:28:45.019: E/AndroidRuntime(432):  at java.lang.reflect.Method.invokeNative(Native Method)
02-28 12:28:45.019: E/AndroidRuntime(432):  at java.lang.reflect.Method.invoke(Method.java:507)
02-28 12:28:45.019: E/AndroidRuntime(432):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-28 12:28:45.019: E/AndroidRuntime(432):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-28 12:28:45.019: E/AndroidRuntime(432):  at dalvik.system.NativeStart.main(Native Method)

Meothos Logcat表明它会导致错误：

public void retrieveRecords() {
    int c = mpoh.getCurrentRowNumber();
    String t = mpoh.getMP_Time(c);
    String d = mpoh.getMP_Date(c);
    double pitch = mpRM.getPich();
    double yaw = mpRM.getYaw();

    tv_Time = (TextView) findViewById(R.id.tv_Time_Value);
    tv_Date = (TextView) findViewById(R.id.tv_Date_Value);

    tv_pitch = (TextView) findViewById(R.id.tv_Pitch_Value);
    tv_yaw = (TextView) findViewById(R.id.tv_Yaw_Value);

    tv_Time.setText(t);
    tv_Date.setText(d);
    tv_pitch.setText(Double.toString(pitch));
    tv_yaw.setText(Double.toString(yaw));
}

MP_DB：

public class MP_DB extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 2;
private static final String DATABASE_NAME = "MP.db";
private static final String MP_TABLE_NAME = "MPData";

MP_DB (Context context) { 
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}// end of 

@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub
    db.execSQL(" CREATE TABLE " + MP_TABLE_NAME + " ( " +
            BaseColumns._ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
            " name TEXT, " +
            " lat REAL, " +
            " lng REAL, " +
            " date TEXT, " +
            " time TEXT " +
            ");" );
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

}

public String getMP_Name(long id) {
    SQLiteDatabase db = this.getReadableDatabase();
    SQLiteCursor c = (SQLiteCursor) db.rawQuery("SELECT name FROM MPData WHERE "+
                                                BaseColumns._ID+" = "+
                                                Long.toString(id) +" AND name IS NOT NULL ", null);
    c.moveToFirst();
    String r = c.getString(0);
    c.close();
    db.close();

    return r;       
}

public int countRows(SQLiteCursor c) {
    return c.getCount();
}

public String getMP_Time(long id) {
    SQLiteDatabase db = this.getReadableDatabase();
    SQLiteCursor c = (SQLiteCursor) db.rawQuery("SELECT time FROM MPData WHERE "+
                                                BaseColumns._ID+" = "+
                                                Long.toString(id), null);
    c.moveToFirst();
    String r = c.getString(0);
    c.close();
    db.close();
    return r;       
}

MyLocations.java中的一些方法：

private void get_MPNames() {
    int[] x = mpoh.getIDs();
    str = new String[x.length];

    for (int i=0; i < x.length; i++) {
          str[i] = mpoh.getMP_Name(x[i]);
    } 
    Toast.makeText(this, getRowsNum()+" names left in DB", Toast.LENGTH_SHORT).show();
}
private void deleteMPfromListView(int pos) {
    al.remove(pos);
    adapter.notifyDataSetChanged();
    Toast.makeText(getBaseContext(), al.size()+" rows left in list view", Toast.LENGTH_SHORT).show();
}

private void deleteMPFromDB(int pos) {
    int []x = mpoh.getIDs();
    mpoh.deleteMP(x[pos]);
    Toast.makeText(getBaseContext(), getRowsNum()+" rows left in DB", Toast.LENGTH_SHORT).show();
}

Answer 1

尝试从db.close()删除c.close()和SQLiteOpenHelper，并在每个startManagingCursor(c)后使用rawQuery。即使您在LogCat中收到警告，这也应该有效。关闭onDestroy中的数据库以删除警告。

删除另一行后插入行时SQLite出错

1 个答案: