如何总结Sqlite数据库的Veritacal列，然后在Excel表格Android中导出

我如何可以通过Sqlite数据库命名我的列的总和？ 我想和我input的金额同时插入然后在创build的Excel表中插入Total金额。只是帮助是如此appriciate.Thank你在提前。

public void saveExcelFile() { try { dbHelper = new DBHelper(MainActivity.this); final Cursor cursor = dbHelper.getuser(selectedDate); //create directory if not exist if (!directory.isDirectory()) { directory.mkdirs(); } File file = new File(directory, edtDate.getText().toString() + ".xls"); WorkbookSettings wbSettings = new WorkbookSettings(); wbSettings.setLocale(new Locale("en", "EN")); WritableWorkbook workbook; workbook = Workbook.createWorkbook(file, wbSettings); //Excel sheet name. 0 represents first sheet WritableSheet sheet = workbook.createSheet("userList", 0); // column and row sheet.addCell(new Label(0, 0, "id")); sheet.addCell(new Label(1, 0, "name")); sheet.addCell(new Label(2, 0, "email")); sheet.addCell(new Label(3, 0, "date")); sheet.addCell(new Label(4, 0, "amount")); if (cursor.moveToFirst()) { do { String id = cursor.getString(cursor.getColumnIndex("id")); String name = cursor.getString(cursor.getColumnIndex("name")); String email = cursor.getString(cursor.getColumnIndex("email")); String date = cursor.getString(cursor.getColumnIndex("date")); String amount = cursor.getString(cursor.getColumnIndex("amount")); int i = cursor.getPosition() + 1; sheet.addCell(new Label(0, i, id)); sheet.addCell(new Label(1, i, name)); sheet.addCell(new Label(2, i, email)); sheet.addCell(new Label(3, i, date)); sheet.addCell(new Label(4, i, amount)); } while (cursor.moveToNext()); } //closing cursor cursor.close(); workbook.write(); workbook.close(); Toast.makeText(getApplication(), "Data Exported in a Excel Sheet", Toast.LENGTH_SHORT).show(); } catch (WriteException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } 

Answer 1

做…

1. 添加这个jar文件opencsv-1.7.jar http://www.java2s.com/Code/Jar/o/Downloadopencsv17jar.htm
2. 然后使用这个代码

公共类ExportDatabaseToCSV {

 Context context; public ExportDatabaseToCSV(Context context) { this.context=context; } public void exportDataBaseIntoCSV(){ CredentialDb db = new CredentialDb(context);//here CredentialDb is my database. you can create your db object. File exportDir = new File(Environment.getExternalStorageDirectory(), ""); if (!exportDir.exists()) { exportDir.mkdirs(); } File file = new File(exportDir, "csvfilename.csv"); try { file.createNewFile(); CSVWriter csvWrite = new CSVWriter(new FileWriter(file)); SQLiteDatabase sql_db = db.getReadableDatabase();//here create a method ,and return SQLiteDatabaseObject.getReadableDatabase(); Cursor curCSV = sql_db.rawQuery("SELECT * FROM "+CredentialDb.TABLE_NAME,null); csvWrite.writeNext(curCSV.getColumnNames()); while(curCSV.moveToNext()) { //Which column you want to export you can add over here... String arrStr[] ={curCSV.getString(0),curCSV.getString(1), curCSV.getString(2)}; csvWrite.writeNext(arrStr); } csvWrite.close(); curCSV.close(); } catch(Exception sqlEx) { Log.e("Error:", sqlEx.getMessage(), sqlEx); } } 

}

为了得到列的总和做下面

 Cursor cursor = db.rawQuery("SELECT SUM(" + DbHelper.CART_TOTAL + ") as Total FROM " + DbHelper.CART_TABLE, null); if (cur.moveToFirst()) { int total = cursor.getInt(cursor.getColumnIndex("Total"));// get final total