我最近在我的数据库中添加了第三个表格，我用它来做一个测验应用程序。当我尝试使用第三个表进行测验时，它会崩溃应用程序。我很确定问题出在我的DBhelper中，但我不确定在整个班级的哪个方面。
DBHelper类
public class DBHelper extends SQLiteOpenHelper
{
public DBHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "triviaQuiz";
// tasks table name
private static final String TABLE_QUEST = "quest";
// tasks Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_QUES = "question";
private static final String TABLE_QUEST2 = "quest2";
// tasks Table Columns names
private static final String KEY_ID2 = "id";
private static final String KEY_QUES2 = "question";
private static final String TABLE_QUEST3 = "quest3";
// tasks Table Columns names
private static final String KEY_ID3 = "id";
private static final String KEY_QUES3 = "question";
private static final String KEY_ANSWER = "answer"; //correct option
private static final String KEY_OPTA= "opta"; //option a
private static final String KEY_OPTB= "optb"; //option b
private static final String KEY_OPTC= "optc"; //option c
private SQLiteDatabase dbase;
@Override
public void onCreate(SQLiteDatabase db) {
dbase=db;
String sql = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST + " ( "
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUES
+ " TEXT, " + KEY_ANSWER+ " TEXT, "+KEY_OPTA +" TEXT, "
+KEY_OPTB +" TEXT, "+KEY_OPTC+" TEXT)";
db.execSQL(sql);
addQuestions();
String sql2 = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST2 + " ( "
+ KEY_ID2 + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUES2
+ " TEXT, " + KEY_ANSWER+ " TEXT, "+KEY_OPTA +" TEXT, "
+KEY_OPTB +" TEXT, "+KEY_OPTC+" TEXT)";
db.execSQL(sql2);
addQuestions2();
String sql3 = "CREATE TABLE IF NOT EXISTS " + TABLE_QUEST3 + " ( "
+ KEY_ID3 + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_QUES3
+ " TEXT, " + KEY_ANSWER+ " TEXT, "+KEY_OPTA +" TEXT, "
+KEY_OPTB +" TEXT, "+KEY_OPTC+" TEXT)";
db.execSQL(sql3);
addQuestions3();
//db.close();
}
private void addQuestions()
{
Question q1=new Question("8 X 2 " + "=","16", "20", "18", "16");
this.addQuestion(q1);
Question q2=new Question("8 X 3 " + "=", "20", "24", "26", "24");
this.addQuestion(q2);
Question q3=new Question("8 X 4 " + " =","30", "35","32","32");
this.addQuestion(q3);
Question q4=new Question("8 X 5 " + " = ", "40", "38", "41","40");
this.addQuestion(q4);
Question q5=new Question("8 X 6 " +" =","45","48","50","48");
this.addQuestion(q5);
Question q6=new Question("8 X 7 " +" =","55","56","58","56");
this.addQuestion(q6);
Question q7=new Question("8 X 8 " +" =","64","68","60","64");
this.addQuestion(q7);
Question q8=new Question("8 X 9 " +" =","75","72","70","72");
this.addQuestion(q8);
Question q9=new Question("8 X 10 " +" =","81","89","80","80");
this.addQuestion(q9);
Question q10=new Question("8 X [ ] " +" = 8","1","9","5","1");
this.addQuestion(q10);
Question q11=new Question("8 X [ ] " +" = 24","5","3","6","3");
this.addQuestion(q11);
Question q12=new Question("8 X [ ] " +" = 40","6","9","5","5");
this.addQuestion(q12);
Question q13=new Question("8 X [ ] " +" = 56","7","8","9","7");
this.addQuestion(q13);
Question q14=new Question("8 X [ ] " +" = 80","7","10","9","10");
this.addQuestion(q14);
}
private void addQuestions2()
{
Question q1=new Question("2 X 2 " + "=","4", "2", "6", "4");
this.addQuestion2(q1);
Question q2=new Question("2 X 3 " + "=", "7", "6", "5", "6");
this.addQuestion2(q2);
Question q3=new Question("2 X 4 " + " =","9", "10","8","8");
this.addQuestion2(q3);
Question q4=new Question("2 X 5 " + " = ", "8", "10", "9","10");
this.addQuestion2(q4);
Question q5=new Question("2 X 6 " +" =","12","13","11","12");
this.addQuestion2(q5);
Question q6=new Question("2 X 7 " +" =","13","14","15","14");
this.addQuestion2(q6);
Question q7=new Question("2 X 8 " +" =","16","14","15","16");
this.addQuestion2(q7);
Question q8=new Question("2 X 9 " +" =","17","19","18","18");
this.addQuestion2(q8);
Question q9=new Question("2 X 10 " +" =","21","19","20","20");
this.addQuestion2(q9);
Question q10=new Question("2 X [ ] " +" = 8","1","4","5","4");
this.addQuestion2(q10);
Question q11=new Question("2 X [ ] " +" = 4","2","3","6","2");
this.addQuestion2(q11);
Question q12=new Question("2 X [ ] " +" = 10","6","9","5","5");
this.addQuestion2(q12);
Question q13=new Question("2 X [ ] " +" = 14","7","8","9","7");
this.addQuestion2(q13);
Question q14=new Question("2 X [ ] " +" = 20","7","10","9","10");
this.addQuestion2(q14);
}
private void addQuestions3()
{
Question q1=new Question("2 X 2 " + "=","4", "2", "6", "4");
this.addQuestion2(q1);
Question q2=new Question("2 X 3 " + "=", "7", "6", "5", "6");
this.addQuestion2(q2);
Question q3=new Question("2 X 4 " + " =","9", "10","8","8");
this.addQuestion2(q3);
Question q4=new Question("2 X 5 " + " = ", "8", "10", "9","10");
this.addQuestion2(q4);
Question q5=new Question("2 X 6 " +" =","12","13","11","12");
this.addQuestion2(q5);
Question q6=new Question("2 X 7 " +" =","13","14","15","14");
this.addQuestion2(q6);
Question q7=new Question("2 X 8 " +" =","16","14","15","16");
this.addQuestion2(q7);
Question q8=new Question("2 X 9 " +" =","17","19","18","18");
this.addQuestion2(q8);
Question q9=new Question("2 X 10 " +" =","21","19","20","20");
this.addQuestion2(q9);
Question q10=new Question("8 X 2 " + "=","16", "20", "18", "16");
this.addQuestion(q10);
Question q12=new Question("8 X 3 " + "=", "20", "24", "26", "24");
this.addQuestion(q12);
Question q13=new Question("8 X 4 " + " =","30", "35","32","32");
this.addQuestion(q13);
Question q14=new Question("8 X 5 " + " = ", "40", "38", "41","40");
this.addQuestion(q14);
Question q15=new Question("8 X 6 " +" =","45","48","50","48");
this.addQuestion(q15);
Question q16=new Question("8 X 7 " +" =","55","56","58","56");
this.addQuestion(q16);
Question q17=new Question("8 X 8 " +" =","64","68","60","64");
this.addQuestion(q17);
Question q18=new Question("8 X 9 " +" =","75","72","70","72");
this.addQuestion(q18);
Question q19=new Question("8 X 10 " +" =","81","89","80","80");
this.addQuestion(q19);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldV, int newV) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_QUEST);
// Create tables again
onCreate(db);
}
// Adding new question
public void addQuestion(Question quest) {
//SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_QUES, quest.getQUESTION());
values.put(KEY_ANSWER, quest.getANSWER());
values.put(KEY_OPTA, quest.getOPTA());
values.put(KEY_OPTB, quest.getOPTB());
values.put(KEY_OPTC, quest.getOPTC());
// Inserting Row
dbase.insert(TABLE_QUEST, null, values);
}
public void addQuestion2(Question quest) {
//SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_QUES2, quest.getQUESTION());
values.put(KEY_ANSWER, quest.getANSWER());
values.put(KEY_OPTA, quest.getOPTA());
values.put(KEY_OPTB, quest.getOPTB());
values.put(KEY_OPTC, quest.getOPTC());
// Inserting Row
dbase.insert(TABLE_QUEST2, null, values);
}
public void addQuestion3(Question quest) {
//SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_QUES3, quest.getQUESTION());
values.put(KEY_ANSWER, quest.getANSWER());
values.put(KEY_OPTA, quest.getOPTA());
values.put(KEY_OPTB, quest.getOPTB());
values.put(KEY_OPTC, quest.getOPTC());
// Inserting Row
dbase.insert(TABLE_QUEST3, null, values);
}
public List<Question> getAllQuestions() {
List<Question> quesList = new ArrayList<Question>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_QUEST;
dbase=this.getReadableDatabase();
Cursor cursor = dbase.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Question quest = new Question();
quest.setID(cursor.getInt(0));
quest.setQUESTION(cursor.getString(1));
quest.setANSWER(cursor.getString(2));
quest.setOPTA(cursor.getString(3));
quest.setOPTB(cursor.getString(4));
quest.setOPTC(cursor.getString(5));
quesList.add(quest);
} while (cursor.moveToNext());
}
// return quest list
return quesList;
}
public List<Question> getAllQuestions2() {
List<Question> quesList = new ArrayList<Question>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_QUEST2;
dbase=this.getReadableDatabase();
Cursor cursor = dbase.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Question quest = new Question();
quest.setID(cursor.getInt(0));
quest.setQUESTION(cursor.getString(1));
quest.setANSWER(cursor.getString(2));
quest.setOPTA(cursor.getString(3));
quest.setOPTB(cursor.getString(4));
quest.setOPTC(cursor.getString(5));
quesList.add(quest);
} while (cursor.moveToNext());
}
// return quest list
return quesList;
}
public List<Question> getAllQuestions3() {
List<Question> quesList = new ArrayList<Question>();
// Select All Query
String selectQuery = "SELECT * FROM " + TABLE_QUEST3;
dbase=this.getReadableDatabase();
Cursor cursor = dbase.rawQuery(selectQuery, null);
// looping through all rows and adding to list
if (cursor.moveToFirst()) {
do {
Question quest = new Question();
quest.setID(cursor.getInt(0));
quest.setQUESTION(cursor.getString(1));
quest.setANSWER(cursor.getString(2));
quest.setOPTA(cursor.getString(3));
quest.setOPTB(cursor.getString(4));
quest.setOPTC(cursor.getString(5));
quesList.add(quest);
} while (cursor.moveToNext());
}
// return quest list
return quesList;
}
public int rowcount()
{
int row=0;
String selectQuery = "SELECT * FROM " + TABLE_QUEST;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
row=cursor.getCount();
return row;
}
}
这是调用第三个表的类
public class Combine extends Activity
{
Random randomGenerator = new Random();
int rand1 = randomGenerator.nextInt(18);
int rand2;
List<Question> quesList;
int score=0;
int qid=0;
Question currentQ;
TextView txtQuestion;
Button rda, rdb, rdc;
Button butNext;
MediaPlayer mysound;
boolean loaded=false;
private SoundPool soundPool,soundPool2;
int soundID, soundID2;
private Chronometer chrono;
int timer =60;
String count = "01:00";
@Override
public void onBackPressed() {
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_combine);
DBHelper db=new DBHelper(this);
quesList=db.getAllQuestions3();
currentQ=quesList.get(rand1);
txtQuestion=(TextView)findViewById(R.id.textView1);
rda=(Button)findViewById(R.id.radio0);
rdb=(Button)findViewById(R.id.radio1);
rdc=(Button)findViewById(R.id.radio2);
rda.setOnClickListener(onClickListener);
rdb.setOnClickListener(onClickListener);
rdc.setOnClickListener(onClickListener);
this.chrono = (Chronometer) findViewById(R.id.calling_crono);
startCrono();
//butNext=(Button)findViewById(R.id.button1);
setQuestionView();
chrono.setOnChronometerTickListener(new OnChronometerTickListener() {
public void onChronometerTick(Chronometer chronometer)
{
String currentTime= chrono.getText().toString();
timer --;
count = "00:"+timer;
Date date = null;
try {
date = new SimpleDateFormat("mm:ss").parse(currentTime);
}catch (java.text.ParseException e)
{
e.printStackTrace();
}
String newTime = new SimpleDateFormat("mm:ss").format(date);
if(newTime.equals("01:00"))
{
chrono.stop();
Intent intent = new Intent(Combine.this, ResultActivity.class);
Bundle b = new Bundle();
int end = -5;
b.putInt("score", score);
b.putInt("end", end);
intent.putExtras(b);
soundPool.release();
soundPool2.release();
startActivity(intent);
finish();
}
}
});
soundPool = new SoundPool(10, AudioManager.STREAM_MUSIC, 0);
soundPool.setOnLoadCompleteListener(new OnLoadCompleteListener() {
@Override
public void onLoadComplete(SoundPool soundPool, int sampleId,
int status) {
loaded = true;
}
});
soundID = soundPool.load(this, R.raw.correct, 1);
soundPool2 = new SoundPool(10, AudioManager.STREAM_MUSIC, 0);
soundPool2.setOnLoadCompleteListener(new OnLoadCompleteListener() {
@Override
public void onLoadComplete(SoundPool soundPool, int sampleId,
int status) {
loaded = true;
}
});
soundID2 = soundPool2.load(this, R.raw.error, 1);
}
private OnClickListener onClickListener = new OnClickListener() {
@Override
public void onClick(View v)
{
int rand2 = randomGenerator.nextInt(18);
TextView answer = (TextView) v;
if(currentQ.getANSWER().equals(answer.getText()))
{
score++;
AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
float actualVolume = (float) audioManager
.getStreamVolume(AudioManager.STREAM_MUSIC);
float maxVolume = (float) audioManager
.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
float volume = actualVolume / maxVolume;
soundPool.play(soundID, volume, volume, 1, 0, 1f);
Log.e("Test", "Played sound");
}
else
{
AudioManager audioManager = (AudioManager) getSystemService(AUDIO_SERVICE);
float actualVolume = (float) audioManager
.getStreamVolume(AudioManager.STREAM_MUSIC);
float maxVolume = (float) audioManager
.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
float volume = actualVolume / maxVolume;
soundPool2.play(soundID2, volume, volume, 1, 0, 1f);
Log.e("Test", "Played sound");
}
currentQ=quesList.get(rand2);
setQuestionView();
}
};
public void startCrono() {
chrono.setBase(SystemClock.elapsedRealtime());
chrono.start();
}
private void setQuestionView()
{
txtQuestion.setText(currentQ.getQUESTION());
rda.setText(currentQ.getOPTA());
rdb.setText(currentQ.getOPTB());
rdc.setText(currentQ.getOPTC());
qid++;
}
}
需要它的人的logcat
06-17 14:30:01.238: E/AndroidRuntime(10699): FATAL EXCEPTION: main
06-17 14:30:01.238: E/AndroidRuntime(10699): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example/com.example.timestableseasy.Combine}: java.lang.IndexOutOfBoundsException: Invalid index 16, size is 0
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2266)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2316)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.ActivityThread.access$600(ActivityThread.java:150)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1298)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.os.Handler.dispatchMessage(Handler.java:99)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.os.Looper.loop(Looper.java:213)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.ActivityThread.main(ActivityThread.java:5225)
06-17 14:30:01.238: E/AndroidRuntime(10699): at java.lang.reflect.Method.invokeNative(Native Method)
06-17 14:30:01.238: E/AndroidRuntime(10699): at java.lang.reflect.Method.invoke(Method.java:525)
06-17 14:30:01.238: E/AndroidRuntime(10699): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:741)
06-17 14:30:01.238: E/AndroidRuntime(10699): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:557)
06-17 14:30:01.238: E/AndroidRuntime(10699): at dalvik.system.NativeStart.main(Native Method)
06-17 14:30:01.238: E/AndroidRuntime(10699): Caused by: java.lang.IndexOutOfBoundsException: Invalid index 16, size is 0
06-17 14:30:01.238: E/AndroidRuntime(10699): at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:255)
06-17 14:30:01.238: E/AndroidRuntime(10699): at java.util.ArrayList.get(ArrayList.java:308)
06-17 14:30:01.238: E/AndroidRuntime(10699): at com.example.timestableseasy.Combine.onCreate(Combine.java:54)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.Activity.performCreate(Activity.java:5133)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
06-17 14:30:01.238: E/AndroidRuntime(10699): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2230)
06-17 14:30:01.238: E/AndroidRuntime(10699): ... 11 more
log cat指出的第54行是
quesList = db.getAllQuestions3（）; currentQ = quesList.get（RAND 1）;
答案 0 :(得分：1)
您的addQuestion3()方法未向第三个表添加任何内容。它正在添加到第二个和第一个表。因此，当您使用getAllQuestions3()查询第三个表时，它将返回一个空列表，因为第三个表中没有条目。