Android Tutorial - Javatpoint

Basics of Android

Android Sqlite Example

In this example, we are adding a lable on button click and displaying all the added labels on the spinner. As you have seen in the previous example, SQLiteOpenHelper class need to be extended for performing oprations on the sqlite.
We have overridden the onCreate() and onUpgrade() method of SQLiteOpenHelper class in the DatabaseHandler class that provides additional methods to insert and display the lables or data.

Android Sqlite Spinner Example

Let's see the simple code to add and display the string content on spinner using sqlite database.

activity_main.xml

File: activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

     <!-- Label -->
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Add New Label"
        android:padding="8dip" />

    <!-- Input Text -->
    <EditText android:id="@+id/input_label"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="8dip"
        android:layout_marginRight="8dip"/>

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/btn_add"
        android:layout_marginTop="23dp" />

    <Button
        android:id="@+id/btn_add"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/input_label"
        android:layout_centerHorizontal="true"
        android:text="Add Item" />
   
</RelativeLayout>

Activity class

File: MainActivity.java

package com.example.sqlitespinner;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import java.util.List;
import android.content.Context;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends Activity implements OnItemSelectedListener{
    Spinner spinner;
    Button btnAdd;
    EditText inputLabel;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        spinner = (Spinner) findViewById(R.id.spinner);
        btnAdd = (Button) findViewById(R.id.btn_add);
        inputLabel = (EditText) findViewById(R.id.input_label);
 
        spinner.setOnItemSelectedListener(this);
 
        // Loading spinner data from database
        loadSpinnerData();
 
        btnAdd.setOnClickListener(new View.OnClickListener() {
 
            @Override
            public void onClick(View arg0) {
                String label = inputLabel.getText().toString();
 
                if (label.trim().length() > 0) {
                    DatabaseHandler db = new DatabaseHandler(getApplicationContext());
                    db.insertLabel(label);
 
                    // making input filed text to blank
                    inputLabel.setText("");
 
                    // Hiding the keyboard
                    InputMethodManager imm = (InputMethodManager) 
                          getSystemService(Context.INPUT_METHOD_SERVICE);
                    imm.hideSoftInputFromWindow(inputLabel.getWindowToken(), 0);
 
                    // loading spinner with newly added data
                    loadSpinnerData();
                } else {
                    Toast.makeText(getApplicationContext(), "Please enter label name",
                            Toast.LENGTH_SHORT).show();
                }
 
            }
        });
    }
 
    /**
     * Function to load the spinner data from SQLite database
     * */
    private void loadSpinnerData() {
        DatabaseHandler db = new DatabaseHandler(getApplicationContext());
        List<String> lables = db.getAllLabels();
 
        // Creating adapter for spinner
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, lables);
 
        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
 
        // attaching data adapter to spinner
        spinner.setAdapter(dataAdapter);
    }
 
    @Override
    public void onItemSelected(AdapterView<?> parent, View view, int position,
            long id) {
        // On selecting a spinner item
        String label = parent.getItemAtPosition(position).toString();
 
        // Showing selected spinner item
        Toast.makeText(parent.getContext(), "You selected: " + label,
                Toast.LENGTH_LONG).show();
 
    }
 
    @Override
    public void onNothingSelected(AdapterView<?> arg0) {
        // TODO Auto-generated method stub
 
    }
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  // Inflate the menu; this adds items to the action bar if it is present.
  getMenuInflater().inflate(R.menu.activity_main, menu);
  return true;
 }

}

DatabaseHandler class

File: DatabaseHandler.java

package com.example.sqlitespinner2;
import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseHandler extends SQLiteOpenHelper {
    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "spinnerExample";
    private static final String TABLE_NAME = "labels";
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_NAME = "name";
 
    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }
 
    // Creating Tables
    @Override
    public void onCreate(SQLiteDatabase db) {
        // Category table create query
        String CREATE_ITEM_TABLE = "CREATE TABLE " + TABLE_NAME + "("
                + COLUMN_ID + " INTEGER PRIMARY KEY," + COLUMN_NAME + " TEXT)";
        db.execSQL(CREATE_ITEM_TABLE);
    }
 
    // Upgrading database
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop older table if existed
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
 
        // Create tables again
        onCreate(db);
    }
 
    /**
     * Inserting new lable into lables table
     * */
    public void insertLabel(String label){
        SQLiteDatabase db = this.getWritableDatabase();
 
        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME, label);//column name, column value
 
        // Inserting Row
        db.insert(TABLE_NAME, null, values);//tableName, nullColumnHack, CotentValues
        db.close(); // Closing database connection
    }
 
    /**
     * Getting all labels
     * returns list of labels
     * */
    public List getAllLabels(){
        List list = new ArrayList();
 
        // Select All Query
        String selectQuery = "SELECT  * FROM " + TABLE_NAME;
 
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);//selectQuery,selectedArguments
 
        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                list.add(cursor.getString(1));//adding 2nd column data
            } while (cursor.moveToNext());
        }
        // closing connection
        cursor.close();
        db.close();
 
        // returning lables
        return list;
    }
}

Output:

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