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que estoy tratando de copiar una base de datos que hice con gestor de SQLite, en la que lo hice:No se pudo leer la fila 0, columna -1
CREATE TABLE "android_metadata" ("locale" TEXT DEFAULT 'en_US')
y
INSERT INTO "android_metadata" VALUES ('en_US')
Y puse el nombre de todos mis claves principales _id. Mi base de datos se copia (en la primera ejecución hay varios mensajes rojos en el logcat); a partir de entonces, solo da un error cuando lo consulto.
MainActivity
public class MainActivity extends Activity {
String CNAME=" ques",TABLE_NAME=" JAVAQ";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Setupdb dbobj=new Setupdb(this);
try {
//dbobj.close();
dbobj.createDataBase();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
dbobj.openDataBase();
dbobj.close();
try{
SQLiteDatabase sqdb=dbobj.getReadableDatabase();
Cursor c = sqdb.query(TABLE_NAME,
new String[] { CNAME },
null, null, null, null, null);
while (c.moveToNext()) {
String name =
c.getString(c.getColumnIndex(CNAME));
Log.i("LOG_TAG", " HAS NAME " + name);
}}
catch(Exception e){
Log.e("err", e.toString());
}
}}
setupdb
public class Setupdb extends SQLiteOpenHelper {
private static String DB_PATH = "";
private static final String DB_NAME = "camprep.sqlite";
private SQLiteDatabase myDataBase;
private final Context myContext;
private static Setupdb mDBConnection;
public Setupdb(Context context) {
super(context, DB_NAME, null, 3);
this.myContext=context;
DB_PATH="/data/data/"
+ context.getApplicationContext().getPackageName()
+ "/databases/";
Log.e(DB_NAME, DB_PATH);
}
public static synchronized Setupdb getDBAdapterInstance(Context context) {
if (mDBConnection == null) {
mDBConnection = new Setupdb(context);
}
return mDBConnection;
}
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
Log.e("db","exist");
// do nothing - database already exist
} else {
// By calling following method
// 1) an empty database will be created into the default system path of your application
// 2) than we overwrite that database with our database.
this.getReadableDatabase();
try {
Log.e("calling", "copy");
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
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;
}
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 {
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
StackTrace
08-31 20:17:05.320: I/dalvikvm(9457): threadid=3: reacting to signal 3
08-31 20:17:05.370: I/dalvikvm(9457): Wrote stack traces to '/data/anr/traces.txt'
08-31 20:17:05.451: E/camprep.sqlite(9457): /data/data/com.example.mydataexplosion/databases/
08-31 20:17:05.490: E/db(9457): exist
08-31 20:17:05.521: E/CursorWindow(9457): Failed to read row 0, column -1 from a CursorWindow which has 11 rows, 1 columns.
08-31 20:17:05.521: E/err(9457): java.lang.IllegalStateException: Couldn't read row 0, col -1 from CursorWindow. Make sure the Cursor is initialized correctly before accessing data from it.
08-31 20:17:05.650: D/gralloc_goldfish(9457): Emulator without GPU emulation detected.
08-31 20:17:05.650: I/dalvikvm(9457): threadid=3: reacting to signal 3
08-31 20:17:05.670: I/dalvikvm(9457): Wrote stack traces to '/data/anr/traces.txt'
sí funciona ahora, pero debería preocuparme ya que da mensajes de error en el logcat en la primera ejecución. – dreamer1989
@ dreamer1989 Debe preocuparse dependiendo del contenido de los mensajes de error en el logcat. De cualquier forma, pregunta si los mensajes de error son preocupantes o no constituyen una excelente "segunda pregunta". No hagas que esta pregunta sea doblemente útil. –