Android：與光標在SQLite數據庫中的錯誤

Question

我已經做了一些代碼工作完美，但在一些代碼的小清理後，我得到這個錯誤，我已經追溯到光標行動代碼。它記錄Log.d("Start-up",name)而不是Log.d("Start-up","Efter")。我真的不知道出了什麼問題，我希望你能幫助我！

db.execSQL("CREATE TABLE " + DATABASE_TABLE2 + " (" + 
      KEY_ROWID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + 
      NAME + " TEXT NOT NULL, " + 
      PLAYER_1 + " TEXT NOT NULL, " + 
      PLAYER_2 + " TEXT NOT NULL, " + 
      PLAYER_3 + " TEXT NOT NULL, " + 
      PLAYER_4 + " TEXT NOT NULL, " + 
      PLAYER_5 + " TEXT NOT NULL, " + 
      ANTAL + " TEXT NOT NULL, " + 
      OVERSIDDER + " TEXT NOT NULL, " + 
      G + " TEXT NOT NULL, " + 
      LOFT + " TEXT NOT NULL);" 
      ); 




    public boolean doesNameExist(String name){ 
    String[] columns = new String[]{NAME}; 
    Log.d("Start-up",name); 
    Cursor c = ourDatabase.query(DATABASE_TABLE2, columns, NAME + " = '"+ name + "'", null, null, null, null); 
    Log.d("Start-up","Efter"); 
    return c.moveToFirst(); 
} 

這裏是我的logcat：

05-02 16:20:58.168: W/dalvikvm(22533): threadid=1: thread exiting with uncaught exception (group=0x400259f8) 
05-02 16:20:58.178: E/AndroidRuntime(22533): FATAL EXCEPTION: main 
05-02 16:20:58.178: E/AndroidRuntime(22533): java.lang.NullPointerException 
05-02 16:20:58.178: E/AndroidRuntime(22533): at com.jesper.whist.DBHelpeR.doesNameExist(DBHelpeR.java:217) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at com.jesper.whist.Indstillinger$2.onClick(Indstillinger.java:87) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at android.view.View.performClick(View.java:2408) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at android.view.View$PerformClick.run(View.java:8817) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at android.os.Handler.handleCallback(Handler.java:587) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at android.os.Handler.dispatchMessage(Handler.java:92) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at android.os.Looper.loop(Looper.java:144) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at android.app.ActivityThread.main(ActivityThread.java:4937) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at java.lang.reflect.Method.invokeNative(Native Method) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at java.lang.reflect.Method.invoke(Method.java:521) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
05-02 16:20:58.178: E/AndroidRuntime(22533): at dalvik.system.NativeStart.main(Native Method) 

編輯：全班

package com.jesper.whist; 

public class Indstillinger extends Activity{ 

//Variables 
public static final String MY_SETTINGS = "MySettings"; 
EditText name,G,loft,player1,player2,player3,player4,player5; 
String antal; 
TextView playertext5, overskrift; 
Typeface tf; 
CheckBox femSpiller; 
SharedPreferences settings; 
Toast display; 
int id; 
Button ok_inst; 
DBHelpeR entry; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    // Remove app-name 
    this.requestWindowFeature(Window.FEATURE_NO_TITLE); 

    // Set heading font 
    setContentView(R.layout.indstillinger); 
    tf = Typeface.createFromAsset(getAssets(), "FargoFaroNF.ttf"); 
    overskrift = (TextView) findViewById(R.id.indstillinger); 
    overskrift.setTypeface(tf); 

    // Setting up Shared prefenceres and database 
    settings = getSharedPreferences(MY_SETTINGS, 0); 
    entry = new DBHelpeR(Indstillinger.this); 

    // More variables 
    G = (EditText) findViewById(R.id.etG); 
    G.setText("15"); 
    loft = (EditText) findViewById(R.id.etLoft); 
    loft.setText("10000"); 
    name = (EditText) findViewById(R.id.etName); 
    player1 = (EditText) findViewById(R.id.etPlayer1); 
    player2 = (EditText) findViewById(R.id.etPlayer2); 
    player3 = (EditText) findViewById(R.id.etPlayer3); 
    player4 = (EditText) findViewById(R.id.etPlayer4); 
    player5 = (EditText) findViewById(R.id.etPlayer5); 
    playertext5 = (TextView) findViewById(R.id.tvPlayer5); 
    femSpiller = (CheckBox) findViewById(R.id.cb_fem); 
    ok_inst = (Button) findViewById(R.id.bInst); 

    // Toast 
    display = Toast.makeText(this, "Navnet er optaget! Vælg et nyt!", Toast.LENGTH_SHORT); 

    // Get id from Shared Preferences 
    id = settings.getInt("game_id", 0); 

    // Hvis 5-spillere-checkboxen checkes, vis indstillingsmuligheder 
    femSpiller.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){ 
     @Override 
     public void onCheckedChanged(CompoundButton buttonView, 
     boolean isChecked) { 
      playertext5.setVisibility(View.VISIBLE); // Vis TextView 
      player5.setVisibility(View.VISIBLE); // Vis EditText 
     } 
     }); 

    // Ved klik på ok-knappen 
    ok_inst.setOnClickListener(new View.OnClickListener() { 

     public void onClick(View v) { 

      // Check if name exist 
      if(entry.doesNameExist(name.getText().toString())==true){ 
       display.show();  // Vis toast 
      } 
      // Hvis navnet ikke eksistere 
      else{ 
       if(femSpiller.isChecked()){antal = "5";} // Hvis der er 5 spillere 
       else{antal = "4";}  // Hvis der er 4 spillere 


       entry.open(); 

       // Lav entry i Spil_table: spil navn, spillernavne, antal, oversidder=5 så sidste man sidder over i første runde, grundtakst, loft 
       entry.createEntrySpil(name.getText().toString(), player1.getText().toString(), player2.getText().toString(), player3.getText().toString(), player4.getText().toString(), player5.getText().toString(), antal,"5", G.getText().toString(), loft.getText().toString()); 
       entry.createEntryPenge(id,"0","0","0","0","0"); // Lav en nul-entry så det virker 
       entry.close(); 

       // Start WHIST! og afslut denne proces 
       startActivity(new Intent("com.jesper.whist.WHIST")); 
       finish(); 
       } 


     } 
    }); 
} 

}

Answer 1

嘛，從你的logcat我會看在兩個地方......

Indstillinger圍繞線87

和

DBHelpeR圍繞線217

後的代碼這些部分，也許我們可以多一點幫助。

編輯

好吧，我看到光標位貼（剛剛醒來，抱歉）。我真的沒有看到這個查詢有什麼問題（假設你已經定義了ourDatabase，因爲你沒有在你發佈的代碼中顯示），所以我會看第87行的Indstillinger。這似乎是第一個參考到錯誤日誌中的代碼。

2ND編輯

您正在使用需要的DB你打開它之前是開放的方法。在調用doesNameExist之前先執行entry.open（）。

Answer 2

沒有一個特定的錯誤，這只是一種猜測，但：

在一些代碼小清理後，我得到這個錯誤

你改變了表結構嗎？如果是這樣，你需要重建數據庫，最簡單的方法是增加DATABASE_VERSION。

加成

null指針異常是指變量，大概ourDatabase，尚未定義。