我在创建SQLite数据库时遇到问题。程序运行正常,直到我尝试访问活动中的数据库,当它崩溃时。我怀疑创建表的代码有问题,但我找不到错误。
在尝试将数据添加到数据库时查看设备的logcat,我看到以下条目:
table scoretable has no column named persons_score
和
Error inserting persons_score=10 persons_name=me
和
blablaSQLiteException: table scoretable has no column named persons_score (code 1): , while compiling: INSERT INTO scoretable (persons_score,persons_name) VALUES (?,?)
以下是代码:
HighScore :(数据库类)
public class HighScore {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "persons_name";
public static final String KEY_SCORE = "persons_score";
private static final String DATABASE_NAME = "highscoredb";
private static final String DATABASE_TABLE = "scoretable";
private static final int DATABASE_VERSION = 1;
private DbHelper ourHelper;
private final Context ourContext;
private SQLiteDatabase ourDatabase;
private static class DbHelper extends SQLiteOpenHelper{
public DbHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db){
db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" +
KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
KEY_NAME + " TEXT NOT NULL, " +
KEY_SCORE + " TEXT NOT NULL);"
);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
onCreate(db);
}
}
public HighScore(Context c){
ourContext = c;
}
public HighScore open(){
ourHelper = new DbHelper(ourContext);
ourDatabase = ourHelper.getWritableDatabase();
return this;
}
public void close(){
ourHelper.close();
}
public long createEntry(String name, String resultat){
ContentValues cv = new ContentValues();
cv.put(KEY_NAME, name);
cv.put(KEY_SCORE, resultat);
return ourDatabase.insert(DATABASE_TABLE, null, cv);
}
public String getData(){
String[] columns = new String[]{ KEY_ROWID, KEY_NAME, KEY_SCORE};
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, null, null, null, null, null);
String result = "";
int iRow = c.getColumnIndex(KEY_ROWID);
int iName = c.getColumnIndex(KEY_NAME);
int iScore = c.getColumnIndex(KEY_SCORE);
for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()){
result = result + c.getString(iRow) + " " + c.getString(iName) + " " + c.getString(iScore) + "\n";
}
return result;
}
}
Results.java (用户可以看到他的分数并选择将其添加到数据库中,当点击viewHighscore按钮时,应用程序崩溃。)
public class Resultat extends Activity implements View.OnClickListener {
Button addHighScore, viewHighScore;
TextView dittResultat;
int resultat;
String name;
String stringResultat;
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.resultat);
addHighScore = (Button) findViewById(R.id.addhighscore);
viewHighScore = (Button) findViewById(R.id.viewhighscore);
dittResultat = (TextView) findViewById(R.id.dittresultat);
addHighScore.setOnClickListener(this);
viewHighScore.setOnClickListener(this);
Globals g = (Globals)getApplication();
resultat = g.getData();
String name = ((Globals) this.getApplication()).getTypedName();
dittResultat.setText("Gratulerer " + name + " , du har gjennomført quizen og fikk" + resultat + " av 10 riktige!" );
}
public void onClick(View arg0){
switch (arg0.getId()){
case R.id.addhighscore:
boolean didItWork = true;
try{
Globals g = (Globals)getApplication();
name = ((Globals) this.getApplication()).getTypedName();
resultat = g.getData();
stringResultat = Integer.toString(resultat);
HighScore entry = new HighScore(Resultat.this);
entry.open();
entry.createEntry(name, stringResultat);
entry.close();
}catch (Exception e){
didItWork = false;
String error = e.toString();
Dialog d = new Dialog(this);
d.setTitle("NEI!");
TextView tv = new TextView(this);
tv.setText(error);
d.setContentView(tv);
d.show();
} finally{
if(didItWork){
Dialog d = new Dialog(this);
d.setTitle("Wee!");
TextView tv = new TextView(this);
tv.setText("Det funka!");
d.setContentView(tv);
d.show();
}
}
break;
case R.id.viewhighscore:
Intent myIntent2 = new Intent(Resultat.this, HighScoreView.class);
startActivity(myIntent2);
break;
}
}
}
List.java (尝试显示数据库查询结果的简单textview,打开此类会使应用程序崩溃)。
public class HighScoreView extends Activity {
TextView liste;
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.highscoreview);
liste = (TextView)findViewById(R.id.liste);
HighScore hsListe = new HighScore(this);
hsListe.open();
String data = hsListe.getData();
hsListe.close();
liste.setText(data);
}
}
答案 0 :(得分:1)
最近添加了更多表/列?尝试卸载您的应用并再次安装它以再次完成创建。数据库只创建一次,因此升级应用程序时不会再次调用onCreate
中的代码。
答案 1 :(得分:0)
您可能在创建数据库后添加了persons_score
列。只需为您的应用做一个清晰的数据,或卸载然后重新运行该应用。
那应该解决它。
希望这有帮助
答案 2 :(得分:0)
这可能是因为您在设备中创建数据后最近添加了列,从此处粘贴的代码看到我无法弄清楚其中的任何错误。
点是每当您更改数据库架构时,您需要将版本号更改为高于之前的版本,否则android将无法升级您的数据库,无法在升级时执行。所以即使你做对了,你的数据库也无法注册更改。
作为解决方案,卸载并安装您的应用程序或更改数据库版本并重新安装。确保您将来参考,特别是当您的应用程序上线时,跟踪您的数据库版本,并在更改架构时始终更改它。