How to get data from a database using a cursor? (Android, SQLite)

I am stuck. I cannot understand what I am doing wrong, so please help someone. Although this is a fairly simple task, I do not understand what the database looks like.

Here is the code that I use to insert data into a table in a database:

EditText title = (EditText)findViewById(R.id.Title); 
String Title = title.getText().toString();

EditText d = (EditText)findViewById(R.id.director); 
String Director = d.getText().toString();

SQLiteDatabase db = openOrCreateDatabase("Films", MODE_PRIVATE, null);
db.execSQL("CREATE TABLE IF NOT EXISTS MyFilms (idFilm INTEGER PRIMARY KEY AUTOINCREMENT, Title VARCHAR, Director VARCHAR, Year INTEGER, Rating INTEGER);");
db.execSQL("INSERT INTO MyFilms (Title) VALUES('" + Title + "');");
db.execSQL("INSERT INTO MyFilms (Director) VALUES('" + Director + "');");
db.close();

This code gives me a table with columns idfilm, Title, Director, Year, Rating? If so, there is still a problem when I try to get all the headers from a column Titleusing this code:

SQLiteDatabase db = openOrCreateDatabase("Films", MODE_PRIVATE, null);
Cursor c = db.rawQuery("SELECT * FROM MyFilms",null);
c.moveToFirst();

while (c.isAfterLast() == false) {
  String Title = c.getString(c.getColumnIndex("Director"));         
  stringList.add(Title); //This I use to create listlayout dynamically and show all the Titles in it
  c.moveToNext();
}

Error Log:

05-21 17:50:14.666: E/AndroidRuntime(27045): FATAL EXCEPTION: main
05-21 17:50:14.666: E/AndroidRuntime(27045): java.lang.NullPointerException
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.ArrayAdapter.createViewFromResource(ArrayAdapter.java:355)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.ArrayAdapter.getView(ArrayAdapter.java:323)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.AbsListView.obtainView(AbsListView.java:1409)
 05-21 17:50:14.666: E/AndroidRuntime(27045):   at android.widget.ListView.measureHeightOfChildren(ListView.java:1216)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.ListView.onMeasure(ListView.java:1127)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.View.measure(View.java:8313)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.RelativeLayout.measureChild(RelativeLayout.java:566)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:381)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.View.measure(View.java:8313)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.View.measure(View.java:8313)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.View.measure(View.java:8313)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.View.measure(View.java:8313)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.ViewRoot.performTraversals(ViewRoot.java:839)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.os.Looper.loop(Looper.java:123)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at android.app.ActivityThread.main(ActivityThread.java:3683)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at java.lang.reflect.Method.invokeNative(Native Method)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at java.lang.reflect.Method.invoke(Method.java:507)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-21 17:50:14.666: E/AndroidRuntime(27045):    at dalvik.system.NativeStart.main(Native Method)

DDMS NullPointerException? ""? c.getString(), c.getString(1), NullPointerException, "Director", c.getString(2). , !

+3
3

, ( ).

INSERT:

db.execSQL("INSERT INTO MyFilms (Title, Director, Year) VALUES('" 
    + title + "','" + director + "'," + year + ");");

, Title Director.

(: SQL , SQL-. . . Bobby).

:

+3

edittext. .    

Cursor c = db.rawQuery("SELECT * FROM MyFilms",null);

if (c != null ) {
        if  (c.moveToFirst()) {
              do {
              String dir = c.getString(c.getColumnIndex("Director"));
              test.add("" + dir );
              }while (c.moveToNext());
        }
   }

    this.setListAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,test));

, ListActivity.

+6

.

c.moveToFirst();
        if (c != null) {
            do {
                for (int i = 0; i < c.getColumnCount(); i++) {

                    Log.e("", "" + c.getString(i));
                }
            }while (c.moveToNext());
        }
+3

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