Gudivada Somaraju Hemanth: Android SQLite DB

Android SQLite DB

SQLite Database All Events in Android

1. Insert

2. select All

3. Select

4. Update

5. Delete

Step 1 : Select File -> New -> Project -> Android Application Project (or) Android Project. Fill the forms and click "Finish" button. If you have any doubt regarding create a new project Click Here.

Step 2 : Open res -> layout -> activity_main.xml (or) main.xml and add following code :

Step 3 : Open src -> package -> MainActivity.java and add following code :

package com.gudivada.hemanthsomaraju;

import android.os.Bundle;
import android.app.Activity;
import android.database.Cursor;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

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

        final Button b1=(Button) findViewById(R.id.button1);
        final Button b2=(Button) findViewById(R.id.button2);
        final Button b3=(Button) findViewById(R.id.button3);
        final Button b4=(Button) findViewById(R.id.button4);
        final Button b5=(Button) findViewById(R.id.button5);

        final EditText et1=(EditText)findViewById(R.id.editText1);
        final EditText et2=(EditText)findViewById(R.id.editText2);
        final EditText et3=(EditText)findViewById(R.id.editText3);

        final DBAdapter db = new DBAdapter(MainActivity.this);

        //---Insert Contact---
        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                db.open();
                db.insertContact(et2.getText().toString(),
                    et3.getText().toString());
                db.close();
                Toast.makeText(getBaseContext(), "Inserted",
                    Toast.LENGTH_SHORT).show();
            }
        });

        //---Select All contacts---
        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                db.open();
                Cursor c = db.getAllContacts();
                if (c.moveToFirst())
                {
                    do {
                        DisplayContact(c);
                    } while (c.moveToNext());
                }
                db.close();
            }

            private void DisplayContact(Cursor c)
            {
                // TODO Auto-generated method stub
                Toast.makeText(getBaseContext(),"id: " + c.getString(0) + "\n" +"Name: " + c.getString(1) + "\n" +"Email: " + c.getString(2),
                    Toast.LENGTH_LONG).show();
            }
        });

        //---Select a contact---
        b3.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                db.open();
                Cursor c = db.getContact(Integer.parseInt
                    (et1.getText().toString()));
                if (c.moveToFirst())
                    DisplayContact(c);
                else
                    Toast.makeText(getBaseContext(), "No contact found",
                        Toast.LENGTH_LONG).show();
                db.close();
            }

            private void DisplayContact(Cursor c) {
                // TODO Auto-generated method stub
                Toast.makeText(getBaseContext(),"id: " + c.getString(0) +
                        "\n" +"Name: " + c.getString(1) + "\n" +
                        "Email: " + c.getString(2),
                        Toast.LENGTH_LONG).show();
            }
        }) ;

        //---updates a contact---
        b4.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                db.open();
                if (db.updateContact
                    (Integer.parseInt(et1.getText().toString()),
                    et2.getText().toString(), et3.getText().toString()))

                    Toast.makeText(getBaseContext(), "Updatesuccessful.", Toast.LENGTH_LONG).show();
                else
                    Toast.makeText(getBaseContext(), "Update failed.",
                            Toast.LENGTH_LONG).show();
                db.close();
            }
        });
        //---delete a contact---
        b5.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                db.open();
                db.deleteContact(Integer.parseInt(et1.getText().toString()));
                db.close();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

Step 4 : Open src -> package -> DBAdapter.java and add following code :

package com.gudivada.hemanthsomaraju;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class DBAdapter {
    public static final String KEY_ROWID = "_id";
    public static final String KEY_NAME = "name";
    public static final String KEY_EMAIL = "email";
    private static final String TAG = "DBAdapter";
    private static final String DATABASE_NAME = "MyDB";
    private static final String DATABASE_TABLE = "contacts";
    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_CREATE =
            "create table contacts (_id integer primary key autoincrement, "
                    + "name text not null, email text not null);";
    private final Context context;
    private DatabaseHelper DBHelper;
    private SQLiteDatabase db;

    public DBAdapter(Context ctx)
    {
        this.context = ctx;
        DBHelper = new DatabaseHelper(context);
    }

    private static class DatabaseHelper extends SQLiteOpenHelper
    {
        DatabaseHelper(Context context)
        {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db)
        {
            try {
                db.execSQL(DATABASE_CREATE);
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)
        {
            Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                    + newVersion + ", which will destroy all old data");
            db.execSQL("DROP TABLE IF EXISTS contacts");
            onCreate(db);
        }
    }


    //---opens the database---
    public DBAdapter open() throws SQLException
    {
        db = DBHelper.getWritableDatabase();
        return this;
    }


    //---closes the database---
    public void close()
    {
        DBHelper.close();
    }


    //---insert a contact into the database---
    public long insertContact(String name, String email)
    {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_NAME, name);
        initialValues.put(KEY_EMAIL, email);
        return db.insert(DATABASE_TABLE, null, initialValues);
    }


    //---deletes a particular contact---
    public boolean deleteContact(long rowId)
    {
        return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
    }


    //---retrieves all the contacts---
    public Cursor getAllContacts()
    {
        return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_NAME,KEY_EMAIL},
                null, null, null, null, null);
    }


    //---retrieves a particular contact---
    public Cursor getContact(long rowId) throws SQLException
    {
        Cursor mCursor =db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID,
                KEY_NAME, KEY_EMAIL}, KEY_ROWID + "=" + rowId, null,
                null, null, null, null);
        if (mCursor != null) {
                mCursor.moveToFirst();
        }
        return mCursor;
    }


    //---updates a contact---
    public boolean updateContact(long rowId, String name, String email)
    {
        ContentValues args = new ContentValues();
        args.put(KEY_NAME, name);
        args.put(KEY_EMAIL, email);
        return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
    }
}

Step 5 : Open AndroidManifest.xml and add following code :

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.gudivada.hemanthsomaraju"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.gudivada.hemanthsomaraju.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Step 6 : Open res ->values ->strings.xml and add following code :

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <string name="app_name">HemanthSomaraju</string>
    <string name="action_settings">Settings</string>
    <string name="hello_world">Hello world!</string>

    <string name="h_id">Id</string>
    <string name="h_nm">Name</string>
    <string name="h_em">Mail</string>
    <string name="h_ins">Insert</string>
    <string name="h_sel">Select</string>
    <string name="h_sall">Selectall</string>
    <string name="h_upd">Update</string>
    <string name="h_del">Delete</string>
</resources>

Step 7 : Our output will be like this :

Android SQLite DB

Android SQLite DB

SQLite Database All Events in Android

1. Insert

2. select All

3. Select

4. Update

5. Delete