Versucht, Spalte aus einer Tabelle zusammenzufassen MySql

Question

Ich versuche, die Spalte quantityTaken für jedes itemNo, und versuchen, es einmal für jedes itemNo in der Tabellenansicht anzuzeigen, wird jede Hilfe geschätzt werden. Dies ist mein Code: ich hoffe, dass Sie meine Bitte verstehen

@FXML 
    private void populateTableView() { 
     int totalQuantityTaken = 0; 

     try { 

      /* SQL QUERY */ 
      String sql = "SELECT employeeName, itemNo, itemName, timeTaken, quantityTaken FROM UsedProduct\n" + 
        "INNER JOIN Employee ON\n" + 
        "UsedProduct.employeeBarcode = Employee.employeeBarcode\n" + 
        "INNER JOIN Item ON\n" + 
        "UsedProduct.itemBarcode = Item.itemBarcode\n" + 
        "WHERE Item.itemNo = ?;"; 

      /* EXECUTION OF QUERY */ 
      String inputBarcode = tfSearch.getText(); 
      PreparedStatement preparedStatement = connectDB.preparedStatement(sql); 
      preparedStatement.setString(1, inputBarcode); 

      ResultSet result = preparedStatement.executeQuery(); 

      while (result.next()){ 
       int quantityTaken = result.getInt("quantityTaken"); 
       totalQuantityTaken = quantityTaken + totalQuantityTaken; 
      } 

      while (result.next()) { 

       String employeeName = result.getString("employeeName"); 
       String itemNumber = result.getString("itemNo"); 
       String itemName = result.getString("itemName"); 
       String timeTaken = result.getString("timeTaken"); 
       //String quantityTaken = result.getString("quantityTaken"); 
       UsedProductObj usedProductObj = new UsedProductObj(employeeName, itemNumber, itemName, timeTaken, totalQuantityTaken); 

       searchData.addAll(usedProductObj); 

      } 
     } catch (Exception e) { 
      MainViewController.updateWarningMessage("Error"); 
      e.printStackTrace(); 
      System.out.println("Exception in searchByItemNumberInUsed() from AdminController class: " + e.getMessage()); 
     } 

     /* SETTING VALUES FROM OBJECT INTO COLUMNS */ 
     usedProductEmployeeNameColumn.setCellValueFactory(new PropertyValueFactory<SearchObj, String>("employeeName")); 
     usedProductItemNumberColumn.setCellValueFactory(new PropertyValueFactory<SearchObj, String>("itemNumber")); 
     usedProductItemNameColumn.setCellValueFactory(new PropertyValueFactory<SearchObj, String>("itemName")); 
     usedProductTimeTakenColumn.setCellValueFactory(new PropertyValueFactory<SearchObj, String>("timeTaken")); 
     usedProductQuantityColumn.setCellValueFactory(new PropertyValueFactory<SearchObj, String>("quantityTaken")); 

     /* ADDING THE OBSERVABLE LIST TO THE TABLE VIEW */ 
     usedProductTableView.getItems().setAll(searchData); 
     //searchData.clear(); //i did this because it would duplicate the last element if the item was returned 

    } 

Answer 1

Ich habe den ganzen Code nicht lesen, aber ich denke, was Sie suchen, die GROUP BY-Funktion in MySQL ist. Etwas wie dieses:

SELECT sum(quantityTaken), itemNo FROM UsedProduct GROUP BY itemNo