我正在尝试在我的应用程序中使用 sqlite 数据库。这是运行时的问题
07-26 18:03:10.374：E/AndroidRuntime（1347）：致命异常：主要 07-26 18:03:10.374: E/AndroidRuntime(1347): android.database.sqlite.SQLiteException: 没有这样的表: QUESTIONS (code 1): , 同时编译: SELECT * FROM QUESTIONS 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteProgram.(SQLiteProgram.java:58) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteQuery.(SQLiteQuery.java:37) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1253) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 com.db.DBAdapter.getQuestionSet(DBAdapter.java:143) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 com.example.test_question.MainActivity.getQuestionSetFromDb(MainActivity.java:45) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 com.example.test_question.MainActivity.onClick(MainActivity.java:75) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.view.View.performClick(View.java:4084) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.view.View$PerformClick.run(View.java:16966) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.os.Handler.handleCallback(Handler.java:615) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.os.Handler.dispatchMessage(Handler.java:92) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.os.Looper.loop(Looper.java:137) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 android.app.ActivityThread.main(ActivityThread.java:4745) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 java.lang.reflect.Method.invokeNative(Native Method) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 java.lang.reflect.Method.invoke(Method.java:511) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786) 07-26 18:03:10.374: E/AndroidRuntime(1347): 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 07-26 18:03:10.374: E/AndroidRuntime(1347): at dalvik.system.NativeStart.main(Native Method)
这是代码
public class DBAdapter extends SQLiteOpenHelper {
protected static final String TAG = "DataAdapter";
private static String DB_NAME = "mydb.sqlite";
private SQLiteDatabase myDatabase;
private static Context myContext;
private static String DB_PATH ="/data/data/com/databases/";
public DBAdapter(Context context) {
super(context, DB_NAME, null, 1);
// TODO Auto-generated constructor stub
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own
* database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (!dbExist) {
// By calling this method and empty database will be created into
// the default system path
// of your application so we are gonna be able to overwrite that
// database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error(e.toString());
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created
* empty database in the system folder, from where it can be accessed and
* handled. This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException {
// Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException {
// Open the database
String myPath = DB_PATH + DB_NAME;
myDatabase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if (myDatabase != null)
myDatabase.close();
super.close();
}
public List<Question> getQuestionSet(int numQ) {
List<Question> questionSet = new ArrayList<Question>();
Cursor c = myDatabase.rawQuery("Select * from questions",null);
while (c.moveToNext()) {
Question q = new Question();
q.setSolution(c.getString(0));
q.setOption3(c.getString(1));
q.setOption2(c.getString(2));
q.setOption1(c.getString(3));
q.setAnswer(c.getString(4));
q.setQuestion(c.getString(5));
questionSet.add(q);
}
return questionSet;
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
onCreate(db);
}
感谢帮助