He creado una base de datos. Quiero hacer la transacción. SaveCustomer()contiene más de una instrucción para insertar registros en la Customer, CustomerControl, Profile, Paymenttabla en ese momento.
Cuando un usuario llama al SaveCustomer()método, esos datos irán a estas 4 tablas. Entonces, ¿cómo puedo hacer la transacción? Si las inserciones de una tabla fallaron, es necesario revertir todo. Por ejemplo, cuando la tercera tabla inserta el registro, obtengo un error, entonces también necesito revertir los registros de inserción de dos tablas anteriores.
Ver mi código:
public void saveCustomer(){
DBAdapter dbAdapter = DBAdapter.getDBAdapterInstance(RetailerOrderKeyActivity.this);
dbAdapter.openDataBase();
ContentValues initialValues = new ContentValues();
initialValues.put("CustomerName",customer.getName());
initialValues.put("Address",customer.getAddress());
initialValues.put("CustomerPID",strPID);
initialValues.put("Date",strDateOnly);
long n = dbAdapter.insertRecordsInDB("Customer", null, initialValues);
}
Asimismo, otra declaración también existe.
El código de DBAdpter es:
public long insertRecordsInDB(String tableName, String nullColumnHack,ContentValues initialValues) {
long n =-1;
try {
myDataBase.beginTransaction();
n = myDataBase.insert(tableName, nullColumnHack, initialValues);
myDataBase.endTransaction();
myDataBase.setTransactionSuccessful();
} catch (Exception e) {
// how to do the rollback
e.printStackTrace();
}
return n;
}
Este es el código completo:
public class DBAdapter extends SQLiteOpenHelper {
private static String DB_PATH = "/data/data/com.my.controller/databases/";
private static final String DB_NAME = "customer";
private SQLiteDatabase myDataBase;
private final Context myContext;
private static DBAdapter mDBConnection;
private DBAdapter(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
DB_PATH = "/data/data/"
+ context.getApplicationContext().getPackageName()
+ "/databases/";
// The Android's default system path of your application database is
// "/data/data/mypackagename/databases/"
}
public static synchronized DBAdapter getDBAdapterInstance(Context context) {
if (mDBConnection == null) {
mDBConnection = new DBAdapter(context);
}
return mDBConnection;
}
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
// 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 {
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 {
InputStream myInput = myContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream myOutput = new FileOutputStream(outFileName);
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();
}
/**
* Open the database
* @throws SQLException
*/
public void openDataBase() throws SQLException {
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
/**
* Call on creating data base for example for creating tables at run time
*/
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("ALTER TABLE WMPalmUploadControl ADD Testing int");
}
public void upgradeDb(){
onUpgrade(myDataBase, 1, 2);
}
public Cursor selectRecordsFromDB(String tableName, String[] tableColumns,
String whereClase, String whereArgs[], String groupBy,
String having, String orderBy) {
return myDataBase.query(tableName, tableColumns, whereClase, whereArgs,
groupBy, having, orderBy);
}
public ArrayList<ArrayList<String>> selectRecordsFromDBList(String tableName, String[] tableColumns,
String whereClase, String whereArgs[], String groupBy,
String having, String orderBy) {
ArrayList<ArrayList<String>> retList = new ArrayList<ArrayList<String>>();
ArrayList<String> list = new ArrayList<String>();
Cursor cursor = myDataBase.query(tableName, tableColumns, whereClase, whereArgs,
groupBy, having, orderBy);
if (cursor.moveToFirst()) {
do {
list = new ArrayList<String>();
for(int i=0; i<cursor.getColumnCount(); i++){
list.add( cursor.getString(i) );
}
retList.add(list);
} while (cursor.moveToNext());
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
return retList;
}
public long insertRecordsInDB(String tableName, String nullColumnHack,ContentValues initialValues) {
long n =-1;
try {
myDataBase.beginTransaction();
n = myDataBase.insert(tableName, nullColumnHack, initialValues);
myDataBase.endTransaction();
myDataBase.setTransactionSuccessful();
} catch (Exception e) {
// how to do the rollback
e.printStackTrace();
}
return n;
}
public boolean updateRecordInDB(String tableName,
ContentValues initialValues, String whereClause, String whereArgs[]) {
return myDataBase.update(tableName, initialValues, whereClause,
whereArgs) > 0;
}
public int updateRecordsInDB(String tableName,
ContentValues initialValues, String whereClause, String whereArgs[]) {
return myDataBase.update(tableName, initialValues, whereClause, whereArgs);
}
public int deleteRecordInDB(String tableName, String whereClause,
String[] whereArgs) {
return myDataBase.delete(tableName, whereClause, whereArgs);
}
public Cursor selectRecordsFromDB(String query, String[] selectionArgs) {
return myDataBase.rawQuery(query, selectionArgs);
}
public ArrayList<ArrayList<String>> selectRecordsFromDBList(String query, String[] selectionArgs) {
ArrayList<ArrayList<String>> retList = new ArrayList<ArrayList<String>>();
ArrayList<String> list = new ArrayList<String>();
Cursor cursor = myDataBase.rawQuery(query, selectionArgs);
if (cursor.moveToFirst()) {
do {
list = new ArrayList<String>();
for(int i=0; i<cursor.getColumnCount(); i++){
list.add( cursor.getString(i) );
}
retList.add(list);
} while (cursor.moveToNext());
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
return retList;
}
}
problema de bloqueo de la base de datos en HTC Desire .
Quiero retroceder si se produjo algún problema al insertar los datos de la tabla.
por favor, ayúdame
Gracias.
Miré esta misma pregunta relacionada:
endTransactionsu bloque finalmente, no su bloque de prueba.