Sqllite總是引發NullPointerException異常

//this is in my custom dialog class oncreate method 
InvoiceDatabase invoiceDatabase = new InvoiceDatabase(context); 
TotalInvoiceVO totalInvoiceVo = invoiceDatabase.getPrintInvoiceDetails(custCode); 
invoiceDetails.setText(totalInvoiceVo.toString()); 

//this is my InvoiceDatabase class 
public static String GET_INVOICEDETAILS = "select P.ProductCode productCode, P.MRP mrp, P.SellingRate sellingRate, P.ShortProductDesc desc, P.Vat vat, " + 
      " P.AdditionalTaxes additionalVat," 
      + " P.Cess cess, PalmOrderNo palmOrderNum, " 
      + " SaleQty saleQty, DiscAmount stkDiscount ,SchemeAmount schemeAmount, SchemeDisc schemeDiscount, NetValue netValue from PALM_ORD_DET, PALM_ORDER" 
      + " PRODUCT P where PALM_ORD_DET.ProductCode=PRODUCT.ProductCode and PALM_ORD_DET.PalmOrderNo=PALM_ORDER.PalmOrderNo and PALM_ORDER.CustCode=?"; 

    public TotalInvoiceVO getPrintInvoiceDetails(String custCode) { 
     TotalInvoiceVO totalInvoiceVO = new TotalInvoiceVO(); 
     // getStockiest Detail 
     // get Customer Detail 
     // get CustomerSummary 
     List<InvoiceVO> listOfProductInvoice = getProdOrderInvoiceDetails(custCode); 
     totalInvoiceVO.setListOfProductInvoice(listOfProductInvoice); 
     return totalInvoiceVO; 
    } 

    private List<InvoiceVO> getProdOrderInvoiceDetails(String custCode) { 
     List<InvoiceVO> listOfInvoiceVO = new ArrayList<InvoiceVO>(); 

     Cursor cursor = null; 
     try { 

      /*cursor=db.rawQuery("select * from PALM_ORD_DET", null); 
      if(cursor.moveToFirst()) 
      { 
       String m="m"; 
      }*/ 

      cursor = db.rawQuery(GET_INVOICEDETAILS, new String[] { custCode }); 
      if (cursor.moveToFirst()) { 
       do { 
        InvoiceVO invoiceVO = new InvoiceVO(); 
        invoiceVO.setProdDesc(cursor.getString(cursor.getColumnIndex("desc"))); 
        invoiceVO.setProdCode(cursor.getString(cursor.getColumnIndex("productCode"))); 
        invoiceVO.setMrp(cursor.getDouble(cursor.getColumnIndex("mrp"))); 
        invoiceVO.setSellingPrice(cursor.getDouble(cursor.getColumnIndex("sellingRate"))); 
        invoiceVO.setNetValue(cursor.getDouble(cursor.getColumnIndex("netValue"))); 
        invoiceVO.setStockDiscount(cursor.getString(cursor.getColumnIndex("stkDiscount"))); 
        listOfInvoiceVO.add(invoiceVO); 
       } while (cursor.moveToNext()); 
      } 
     } finally { 
      cursor.close(); 
      cursor=null; 
     }

我是一個新的Android和我試圖從數據庫中檢索值，但情況是，當我查詢數據庫，它總是拋出NullPointerException異常。任何人都可能指出什麼可能是錯的？Sqllite總是引發NullPointerException異常

10-21 20:40:24.098: E/AndroidRuntime(27346): FATAL EXCEPTION: main 
10-21 20:40:24.098: E/AndroidRuntime(27346): java.lang.NullPointerException 
10-21 20:40:24.098: E/AndroidRuntime(27346): at comColgateDMS.org.db.InvoiceDatabase.getProdOrderInvoiceDetails(InvoiceDatabase.java:97) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at comColgateDMS.org.db.InvoiceDatabase.getPrintInvoiceDetails(InvoiceDatabase.java:66) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at comColgateDMS.org.CustomDialog_invoicePrint.onCreate(CustomDialog_invoicePrint.java:46) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.app.Dialog.dispatchOnCreate(Dialog.java:353) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.app.Dialog.show(Dialog.java:257) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at comColgateDMS.org.OrderBookingSummary$1.onItemClick(OrderBookingSummary.java:214) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.widget.AdapterView.performItemClick(AdapterView.java:292) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.widget.AbsListView.performItemClick(AbsListView.java:1065) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2522) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.widget.AbsListView$1.run(AbsListView.java:3183) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.os.Handler.handleCallback(Handler.java:605) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.os.Handler.dispatchMessage(Handler.java:92) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.os.Looper.loop(Looper.java:137) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at android.app.ActivityThread.main(ActivityThread.java:4441) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at java.lang.reflect.Method.invokeNative(Native Method) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at java.lang.reflect.Method.invoke(Method.java:511) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
10-21 20:40:24.098: E/AndroidRuntime(27346): at dalvik.system.NativeStart.main(Native Method) 
10-21 20:40:25.878: I/Process(27346): Sending signal. PID: 27346 SIG: 9

來源

2013-10-21 Sunny

請發佈堆棧跟蹤 –

哪一行是＃97？ – Asahi

cursor.close（）; – Sunny

... from PALM_ORD_DET, PALM_ORDER" 
+ " PRODUCT P where ...

這將連接成

... from PALM_ORD_DET, PALM_ORDER PRODUCT P where ...

這是無效的！

你必須選擇

... from PALM_ORD_DET, PALM_ORDER PRODUCT where ...

或

... from PALM_ORD_DET, PALM_ORDER PRODUCT where ...

，並使用參考相應PALM_ORDER。

來源

2013-10-21 15:58:34

cursor.close（）不正確，如果你想關閉數據庫連接使用sQLiteDatabase.close();

來源

2013-10-21 16:43:00

查詢返回null你不需要，與其這樣，那就是光標是什麼，當你試圖訪問它。您可能需要添加

cursor != null

條件才能訪問它。

來源

2013-10-21 17:08:18 Asahi

確實如此，我很難找出確切的問題。你能告訴我在什麼條件下原始查詢返回null，因爲文檔沒有什麼幫助。 – Sunny

Sqllite總是引發NullPointerException異常

回答

相關問題