无法从android studio.logcat中已创建的sqlite数据库中获取数据显示数据库成功打开。但无法获取数据

Question

我创建了一个数据库＆＃34; dbase＆＃34;在SQLiteManager中并保存在assets文件夹中。该DB包含1个表＆＃34;注释＆＃34; with id（primary ket，integer，autoincrement）ane comment（text）fields.Logcat显示错误：

我的活动课程是：

import android.app.Activity;
import android.database.Cursor;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;

import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;


public class MyActivity extends Activity {
private Cursor em;
private MyDatabase db;
TextView t;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my);
   try {
       db = new MyDatabase(getApplicationContext());
       em = db.getEmployees();
       t = (TextView) findViewById(R.id.txt);
       if (em != null) {
           Integer com = em.getCount();
           t.setText(com);
           do {
              String comment = em.getString(1);
               t.setText(comment);
           } while (em.moveToNext());

       }
   }
   catch(SQLiteAssetHelper.SQLiteAssetException exception)
   { Log.d("checkDatabase", exception.toString());}
}
@Override
protected void onDestroy() {
    super.onDestroy();
    em.close();
    db.close();
}

我的数据库类是：

  import android.content.Context;
   import android.database.Cursor;
  import android.database.sqlite.SQLiteDatabase;
  import android.database.sqlite.SQLiteQueryBuilder;
  import com.readystatesoftware.sqliteasset.SQLiteAssetHelper;
 public class MyDatabase extends SQLiteAssetHelper {
private static final String DATABASE_NAME = "dbase.db";
private static final int DATABASE_VERSION = 1;

public MyDatabase(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);

}

public Cursor getEmployees() {
    SQLiteDatabase db = getReadableDatabase();
    SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
    String[] sqlSelect = {"comment"};
    String sqlTables = "comments";
    qb.setTables(sqlTables);
    Cursor c= db.query(sqlTables,sqlSelect,null,null,null,null,null);
    c.moveToFirst();
    return c;
}

}

logcat打印：

09-08 14:44:03.789  14933-14933/com.example.iyas.ex2 I/SQLiteAssetHelper﹕      successfully opened database dbase.db
 09-08 14:44:03.934  14933-14933/com.example.iyas.ex2 W/ResourceType﹕ No package    identifier when getting value for resource number 0x00000004
 09-08 14:44:04.033  14933-14933/com.example.iyas.ex2 D/AndroidRuntime﹕ Shutting down VM
 09-08 14:44:04.078  14933-14933/com.example.iyas.ex2 E/AndroidRuntime﹕ FATAL    EXCEPTION: main
Process: com.example.iyas.ex2, PID: 14933
java.lang.RuntimeException: Unable to start activity    ComponentInfo{com.example.iyas.ex2/com.example.iyas.ex2.MyActivity}: android.content.res.Resources$NotFoundException: String resource ID #0x4
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2255)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2317)
        at android.app.ActivityThread.access$800(ActivityThread.java:143)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1258)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5070)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:836)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:631)
 Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x4

  

我的xml文件：

RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".MyActivity">

的TextView

android:layout_width="fill_parent"
 android:layout_height="fill_parent"
 android:id="@+id/txt"
 android:layout_centerVertical="true"
 android:layout_centerHorizontal="true" />

/ RelativeLayout的＆GT;