Android Studio SQLite Spinner

Syntax

public class MainActivity extends AppCompatActivity {

    private Spinner spinner;
    private ArrayList<String> categories;
    private ArrayAdapter<String> dataAdapter;
    private SQLiteDatabase db;

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

        spinner = (Spinner) findViewById(R.id.spinner);
        categories = new ArrayList<String>();

        // create database and table if not exist
        createDatabase();

        // add data to spinner
        addDataToSpinner();

        // set spinner listener
        setSpinnerListener();
    }

    private void createDatabase() {
        db = openOrCreateDatabase("DatabaseName", Context.MODE_PRIVATE, null);
        db.execSQL("CREATE TABLE IF NOT EXISTS Categories (id INTEGER PRIMARY KEY AUTOINCREMENT, category_name VARCHAR);");
    }

    private void addDataToSpinner() {
        // get data from the table
        Cursor c = db.rawQuery("SELECT category_name FROM Categories ORDER BY id ASC", null);
        if (c.moveToFirst()) {
            do {
                categories.add(c.getString(c.getColumnIndex("category_name")));
            } while (c.moveToNext());
        }
        c.close();

        // add data adapter to spinner
        dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, categories);
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spinner.setAdapter(dataAdapter);
    }

    private void setSpinnerListener() {
        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String category = parent.getItemAtPosition(position).toString();
                Toast.makeText(parent.getContext(), "Selected: " + category, Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
    }
}

Example

Let's create a simple spinner and populate it with data from a SQLite database table.

<Spinner
    android:id="@+id/spinner"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="16dp" />

Output

When the app is launched, the spinner will be populated with data from the Categories table in the SQLite database.

Explanation

We first create and execute a CREATE TABLE statement to create the Categories table if it doesn't exist. We then retrieve data from the table using a SQL SELECT statement and add it to an ArrayList. Finally, we create an ArrayAdapter and set it as the data adapter for the spinner.

We also set a listener for the spinner so that we can handle the user selecting an item from the dropdown menu.

Use

A spinner is a view that allows users to select one item from a dropdown list. It is often used to provide a selection of options for the user to choose from.

SQLite is a lightweight database that is built into Android. It is often used to store application data on the device.

By combining the spinner and SQLite, you can create a dynamic view that allows users to select data from a database.

Important Points

• Create the SQLite database and table if they don't exist.
• Retrieve data from the table using a SQL SELECT statement.
• Add the data to an ArrayList and create an ArrayAdapter for the spinner.
• Set a listener for the spinner to handle user selections.

Summary

In this tutorial, we learned how to create a spinner in Android Studio and populate it with data from a SQLite database table. By combining the spinner and SQLite, we can create a dynamic view that allows users to select data from a database.