Access Android SQLite Database created in Main Activity from Second activity

Question

I'm trying to insert values in a SQLite Database created in my main activity, from a second activity called by the main. The error i get come from the context when creating a new database open helper, saying that "Main activity is not an enclosing class".

MainActivity.java

public class MainActivity extends AppCompatActivity { private DBOpenHelper tdb; private SQLiteDatabase sdb; private ListView mainlist; private ArrayList<String> al_strings; private ArrayAdapter<String> aa_strings; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); Button btn = (Button) findViewById(R.id.btn); btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { tdb.close(); Intent intent = new Intent(MainActivity.this, SecondActivity.class); startActivity(intent); } }); tdb = new DBOpenHelper(this, "contacts.db", null, 1); sdb = tdb.getWritableDatabase(); String table_name = "contacts"; String[] columns = {"FIRST_NAME", "LAST_NAME"}; String where = null; String where_args[] = null; String group_by = null; String having = null; String order_by = null; Cursor c = sdb.query(table_name, columns, where, where_args, group_by, having, order_by); mainlist = (ListView) findViewById(R.id.mainlist); al_strings = new ArrayList<String>(); c.moveToFirst(); for(int i = 0; i < c.getCount(); i++) { al_strings.add(c.getString(0) + " " + c.getString(1)); c.moveToNext(); } aa_strings = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, al_strings); mainlist.setAdapter(aa_strings); }

SecondActivity.java

public class SecondActivity extends Activity { private DBOpenHelper tdb; private SQLiteDatabase sdb; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_second); Button cancel = (Button) findViewById(R.id.cancel_button); cancel.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { finish(); } }); Button add = (Button) findViewById(R.id.add_button); add.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { EditText first_name = (EditText) findViewById(R.id.et_first_name); EditText last_name = (EditText) findViewById(R.id.et_last_name); EditText home_phone = (EditText) findViewById(R.id.et_home_phone); EditText mobile_phone = (EditText) findViewById(R.id.et_mobile_phone); EditText email = (EditText) findViewById(R.id.et_email); tdb = new DBOpenHelper(MainActivity.this, "contacts.db", null, 1); sdb = tdb.getWritableDatabase(); ContentValues cv = new ContentValues(); cv.put("FIRST_NAME", first_name.getText().toString()); cv.put("LAST_NAME", last_name.getText().toString()); cv.put("HOME_PHONE", home_phone.getText().toString()); cv.put("MOBILE_PHONE", mobile_phone.getText().toString()); cv.put("EMAIL", email.getText().toString()); sdb.insert("contacts", null, cv); al_strings.add(first_name.getText().toString() + " " + last_name.getText().toString()); aa_strings.notifyDataSetChanged(); finish(); } }); } }

Possible duplicate of Not an enclosing class error Android Studio — Kirill
– Kirill, Commented Feb 28, 2017 at 12:24

Shaz Hemani · Accepted Answer · 2017-02-28 12:30:41Z

In this line you have used MainActivity as context

 tdb = new DBOpenHelper(MainActivity.this, "contacts.db", null, 1);

In you DBOpenHelper class contructor param should be Context and you should pass

 tdb = new DBOpenHelper(getApplicationContext(), "contacts.db", null, 1);

Jay Pandya · Accepted Answer · 2017-02-28 12:27:57Z

0

write this in your second activity db = new DBOpenHelper(this, "contacts.db", null, 1);

answered Feb 28, 2017 at 12:27

Jay Pandya

1384 bronze badges

3 Comments

Vishnu Over a year ago

'this ' wont work since, this refers to the OnClickListener

red_deer Over a year ago

I get another error, saying that the DBOpenhelper cannot be applied to the context, as it is an "anonymous...view.view.OnClickListener"

Jay Pandya Over a year ago

then make it SecondActivity.this

Vishnu · Accepted Answer · 2017-02-28 12:28:23Z

In your second activity,

Declare an object of the Context as,

Context context = this;

and instead of

tdb = new DBOpenHelper(MainActivity.this, "contacts.db", null, 1);

instead of this, use like this

tdb = new DBOpenHelper(context, "contacts.db", null, 1);

This may solve your issue. I didn't test it though. Let me know the status also

Jamil · Accepted Answer · 2017-02-28 12:31:02Z

0

A Suggestion :

Create A Separate Class For Database Actions, For Example SQLiteHelper.class Where all the Database Methods like insertion, deletion and Initialization are done, then call this class in any activity by passing context of this activity for example

SQLiteHelper sqh = new SQLiteHelper(con);

Call the required Methods multiple times from single class.

sqh.InsertIntoContacts(values);

edited Feb 28, 2017 at 12:31

answered Feb 28, 2017 at 12:28

Jamil

5,5354 gold badges28 silver badges29 bronze badges

3 Comments

red_deer Over a year ago

My "DBOpenhelper" is already a separated class for database actions. In fact i cannot create a new helper, getting an error with the context parameter.

Jamil Over a year ago

then in "DBOpenHelper" make database Methods there, and call them from any activity like myDBOpenhelper.Insert(values);

Jamil Over a year ago

Secondly for context, In Activity Make Context variable Global, initialize it on onCreate of the activity like mContext = con, and use this mContext in DBOpenHelper(mContext , "contacts.db", null, 1);

Collectives™ on Stack Overflow

Access Android SQLite Database created in Main Activity from Second activity

4 Answers 4

1 Comment

3 Comments

Comments

3 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

1 Comment

3 Comments

Comments

3 Comments

Linked

Related