Why is my record update giving a null pointer exception?

Question

I am creating notepad application and want to update my notes but I am unable to record in sqlite database. Please check my update query I am sharing error details.

public class MainUpdateActivity extends Activity  { 

SQLiteDatabase mydb1;
EditText titleedit,notetextedit;
Button update;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);

        titleedit=(EditText)findViewById(R.id.title);
        notetextedit=(EditText)findViewById(R.id.notetext);
        update=(Button) findViewById(R.id.update);

        Intent myintent = getIntent();

        String product7 = myintent.getStringExtra("product1");
        String product8 = myintent.getStringExtra("product");

        titleedit.setText(product7);
          notetextedit.setText(product8);

update.setOnClickListener(new View.OnClickListener()
            {

            public void onClick(View v)
            {
mydb1.execSQL("UPDATE notes SET (title,notetext) values(?,?);",new String[]{titleedit.getText().toString(),notetextedit.getText().toString()});

Toast.makeText(getApplicationContext(), "note Updated", 3000).show();



            Intent myIntent1 = new Intent(MainUpdateActivity.this,menu.class);

            startActivity(myIntent1);

            finish();

            }

            });

mydb1.execSQL("UPDATE notes SET (title,notetext) values(?,?);",new String[]{titleedit.getText().toString(),notetextedit.getText().toString()}); — raman rayat, Jan 23 '16 at 11:15

score 4 · Answer 1 · answered Jan 23 '16 at 11:29

4

you have declared SQLiteDatabase mydb1 but not initialized it. Error is in this line.

mydb1.execSQL("UPDATE notes SET (title,notetext) values(?,?);",new String[]{titleedit.getText().toString(),notetextedit.getText().toString()});

You need to initialize mydb1.

answered Jan 23 '16 at 11:29

Ravi

34,851
21
122
183

1

thanks i correct it :) – raman rayat Jan 23 '16 at 11:39

score 2 · Accepted Answer · answered Jan 23 '16 at 10:48

2

Looks like in

mydb1.execSQL("UPDATE notes SET (title,notetext) values(?,?);",new String[]{titleedit.getText().toString(),notetextedit.getText().toString()});

mydb1 is null,you didn't new and init mydb1.

answered Jan 23 '16 at 10:48

starkshang

8,228
6
41
52

Note: an **explicit** `.toString()` conversion is not really needed, here, since the inclusion in the string array will automatically perform the **implicit** conversions. – Phantômaxx Jan 23 '16 at 10:50
1

yes,`toString` can be removed. – starkshang Jan 23 '16 at 10:58
no its not null it has two record. – raman rayat Jan 23 '16 at 11:04
@ramanrayat,I mean you don't init value for `mydb1`.For exmaple,you should use `SqlLiteOpenHelper.getWriteableDatabase()` to init it. – starkshang Jan 23 '16 at 11:05
still i didn't get you please correct my code if you can.. – raman rayat Jan 23 '16 at 11:08
Please refer [sqlite doc](http://developer.android.com/intl/es/guide/topics/data/data-storage.html#db),you should create your own `SqlLiteOpenHelper`,and create databse then init `mydb1`. – starkshang Jan 23 '16 at 11:11
i can't do this at this stage because it already a very large code.do you have any other suggestions ? – raman rayat Jan 23 '16 at 11:17
Thanks i correct it by my way ;) public class MainUpdateActivity extends Main1Activity (it include insert query where my database is initializing ) – raman rayat Jan 23 '16 at 11:38

Why is my record update giving a null pointer exception?

2 Answers2