MySQL Databases

SQLite is a opensource SQL database that stores data to a text file on a device. Android comes in with built in SQLite database implementation.

SQLite supports all the relational database features. In order to access this database, you don't need to establish any kind of connections for it like JDBC,ODBC e.t.c

Database – Creation

In order to create a database you just need to call this method openOrCreateDatabase with your database name and mode as a parameter. It returns an instance of SQLite database which you have to receive in your own object.

SQLiteDatabase mydatabase = openOrCreateDatabase("your database name",MODE_PRIVATE,null);

Database – Insertion

we can create table or insert data into table using execSQL method defined in SQLiteDatabase class

mydatabase.execSQL("CREATE TABLE IF NOT EXISTS your database name (Username VARCHAR,Password VARCHAR);");

mydatabase.execSQL("INSERT INTO TutorialsPoint VALUES('admin','admin')

Database – Fetching

We can retrieve anything from database using an object of the Cursor class. We will call a method of this class called rawQuery and it will return a resultset with the cursor pointing to the table.

Cursor resultSet = mydatbase.rawQuery("Select * from database name",null); 

resultSet.moveToFirst(); 

String username = resultSet.getString(0); 

String password = resultSet.getString(1);

Following is the content of the modified MainActivity.java.

import android.content.Context; 

import android.content.Intent; 

import android.support.v7.app.ActionBarActivity; 

import android.os.Bundle; 

 

import android.view.KeyEvent; 

import android.view.Menu; 

import android.view.MenuItem; 

import android.view.View; 

 

import android.widget.AdapterView; 

import android.widget.ArrayAdapter; 

import android.widget.AdapterView.OnItemClickListener; 

import android.widget.ListView; 

 

import java.util.ArrayList; 

import java.util.List; 

 

public class MainActivity extends ActionBarActivity { 

   public final static String EXTRA_MESSAGE = "MESSAGE"; 

   private ListView obj; 

   DBHelper mydb; 

    

   @Override 

   protected void onCreate(Bundle savedInstanceState) { 

      super.onCreate(savedInstanceState); 

      setContentView(R.layout.activity_main); 

       

      mydb = new DBHelper(this); 

      ArrayList array_list = mydb.getAllCotacts(); 

      ArrayAdapter arrayAdapter=new ArrayAdapter(this,android.R.layout.simple_list_item_1, array_list); 

       

      obj = (ListView)findViewById(R.id.listView1); 

      obj.setAdapter(arrayAdapter); 

      obj.setOnItemClickListener(new OnItemClickListener(){ 

         @Override 

         public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) { 

            // TODO Auto-generated method stub 

            int id_To_Search = arg2 + 1; 

             

            Bundle dataBundle = new Bundle(); 

            dataBundle.putInt("id", id_To_Search); 

             

            Intent intent = new Intent(getApplicationContext(),DisplayContact.class); 

             

            intent.putExtras(dataBundle); 

            startActivity(intent); 

         } 

      }); 

   } 

    

   @Override 

   public boolean onCreateOptionsMenu(Menu menu) { 

      // Inflate the menu; this adds items to the action bar if it is present. 

      getMenuInflater().inflate(R.menu.menu_main, menu); 

      return true; 

   } 

    

   @Override 

   public boolean onOptionsItemSelected(MenuItem item){ 

      super.onOptionsItemSelected(item); 

       

      switch(item.getItemId()) { 

         case R.id.item1:Bundle dataBundle = new Bundle(); 

         dataBundle.putInt("id", 0); 

          

         Intent intent = new Intent(getApplicationContext(),DisplayContact.class); 

         intent.putExtras(dataBundle); 

          

         startActivity(intent); 

         return true; 

         default: 

         return super.onOptionsItemSelected(item); 

      } 

   } 

    

   public boolean onKeyDown(int keycode, KeyEvent event) { 

      if (keycode == KeyEvent.KEYCODE_BACK) { 

         moveTaskToBack(true); 

      } 

      return super.onKeyDown(keycode, event); 

   } 

}

Following is the modified content of display contact activity DisplayContact.java

import android.content.Context; 

import android.os.Bundle; 

import android.app.Activity; 

import android.app.AlertDialog; 

 

import android.content.DialogInterface; 

import android.content.Intent; 

import android.database.Cursor; 

 

import android.view.Menu; 

import android.view.MenuItem; 

import android.view.View; 

 

import android.widget.Button; 

import android.widget.TextView; 

import android.widget.Toast; 

 

public class DisplayContact extends Activity { 

   int from_Where_I_Am_Coming = 0; 

   private DBHelper mydb ; 

    

   TextView name ; 

   TextView phone; 

   TextView email; 

   TextView street; 

   TextView place; 

   int id_To_Update = 0; 

    

   @Override 

   protected void onCreate(Bundle savedInstanceState) { 

      super.onCreate(savedInstanceState); 

      setContentView(R.layout.activity_display_contact); 

      name = (TextView) findViewById(R.id.editTextName); 

      phone = (TextView) findViewById(R.id.editTextPhone); 

      email = (TextView) findViewById(R.id.editTextStreet); 

      street = (TextView) findViewById(R.id.editTextEmail); 

      place = (TextView) findViewById(R.id.editTextCity); 

 

      mydb = new DBHelper(this); 

 

      Bundle extras = getIntent().getExtras();  

      if(extras !=null) { 

         int Value = extras.getInt("id"); 

          

         if(Value>0){ 

            //means this is the view part not the add contact part. 

            Cursor rs = mydb.getData(Value); 

            id_To_Update = Value; 

            rs.moveToFirst(); 

             

            String nam = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_NAME)); 

            String phon = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_PHONE)); 

            String emai = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_EMAIL)); 

            String stree = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_STREET)); 

            String plac = rs.getString(rs.getColumnIndex(DBHelper.CONTACTS_COLUMN_CITY)); 

             

            if (!rs.isClosed())  { 

               rs.close(); 

            } 

            Button b = (Button)findViewById(R.id.button1); 

            b.setVisibility(View.INVISIBLE); 

 

            name.setText((CharSequence)nam); 

            name.setFocusable(false); 

            name.setClickable(false); 

 

            phone.setText((CharSequence)phon); 

            phone.setFocusable(false);  

            phone.setClickable(false); 

 

            email.setText((CharSequence)emai); 

            email.setFocusable(false); 

            email.setClickable(false); 

 

            street.setText((CharSequence)stree); 

            street.setFocusable(false);  

            street.setClickable(false); 

 

            place.setText((CharSequence)plac); 

            place.setFocusable(false); 

            place.setClickable(false); 

         } 

      } 

   } 

    

   @Override 

   public boolean onCreateOptionsMenu(Menu menu) { 

      // Inflate the menu; this adds items to the action bar if it is present. 

      Bundle extras = getIntent().getExtras();  

       

      if(extras !=null) { 

         int Value = extras.getInt("id"); 

         if(Value>0){ 

            getMenuInflater().inflate(R.menu.display_contact, menu); 

         } else{ 

            getMenuInflater().inflate(R.menu.menu_main menu); 

         } 

      } 

      return true; 

   } 

 

   public boolean onOptionsItemSelected(MenuItem item) {  

      super.onOptionsItemSelected(item);  

      switch(item.getItemId()) {  

         case R.id.Edit_Contact:  

         Button b = (Button)findViewById(R.id.button1); 

         b.setVisibility(View.VISIBLE); 

         name.setEnabled(true); 

         name.setFocusableInTouchMode(true); 

         name.setClickable(true); 

 

         phone.setEnabled(true); 

         phone.setFocusableInTouchMode(true); 

         phone.setClickable(true); 

 

         email.setEnabled(true); 

         email.setFocusableInTouchMode(true); 

         email.setClickable(true); 

 

         street.setEnabled(true); 

         street.setFocusableInTouchMode(true); 

         street.setClickable(true); 

 

         place.setEnabled(true); 

         place.setFocusableInTouchMode(true); 

         place.setClickable(true); 

 

         return true;  

         case R.id.Delete_Contact: 

 

         AlertDialog.Builder builder = new AlertDialog.Builder(this); 

         builder.setMessage(R.string.deleteContact) 

            .setPositiveButton(R.string.yes, new DialogInterface.OnClickListener() { 

               public void onClick(DialogInterface dialog, int id) { 

                  mydb.deleteContact(id_To_Update); 

                  Toast.makeText(getApplicationContext(), "Deleted Successfully",  

                     Toast.LENGTH_SHORT).show();   

                  Intent intent = new Intent(getApplicationContext(),MainActivity.class); 

                  startActivity(intent); 

               } 

         }) 

         .setNegativeButton(R.string.no, new DialogInterface.OnClickListener() { 

            public void onClick(DialogInterface dialog, int id) { 

               // User cancelled the dialog 

            } 

         }); 

 

         AlertDialog d = builder.create(); 

         d.setTitle("Are you sure"); 

         d.show(); 

 

         return true; 

         default:  

         return super.onOptionsItemSelected(item);  

  

      }  

   }  

 

   public void run(View view) {	 

      Bundle extras = getIntent().getExtras(); 

      if(extras !=null) { 

         int Value = extras.getInt("id"); 

         if(Value>0){ 

            if(mydb.updateContact(id_To_Update,name.getText().toString(), 

               phone.getText().toString(), email.getText().toString(),  

   street.getText().toString(), place.getText().toString())){ 

               Toast.makeText(getApplicationContext(), "Updated", Toast.LENGTH_SHORT).show();	 

               Intent intent = new Intent(getApplicationContext(),MainActivity.class); 

               startActivity(intent); 

            } else{ 

               Toast.makeText(getApplicationContext(), "not Updated", Toast.LENGTH_SHORT).show();	 

            } 

         } else{ 

            if(mydb.insertContact(name.getText().toString(), phone.getText().toString(),  

   email.getText().toString(), street.getText().toString(),  

   place.getText().toString())){ 

                  Toast.makeText(getApplicationContext(), "done", 

   Toast.LENGTH_SHORT).show();	 

            } else{ 

               Toast.makeText(getApplicationContext(), "not done",  

   Toast.LENGTH_SHORT).show();	 

            } 

            Intent intent = new Intent(getApplicationContext(),MainActivity.class); 

            startActivity(intent); 

         } 

      } 

   } 

}

Following is the content of Database class DBHelper.java

import java.util.ArrayList; 

import java.util.HashMap; 

import java.util.Hashtable; 

import android.content.ContentValues; 

import android.content.Context; 

import android.database.Cursor; 

import android.database.DatabaseUtils; 

import android.database.sqlite.SQLiteOpenHelper; 

import android.database.sqlite.SQLiteDatabase; 

 

public class DBHelper extends SQLiteOpenHelper { 

 

   public static final String DATABASE_NAME = "MyDBName.db"; 

   public static final String CONTACTS_TABLE_NAME = "contacts"; 

   public static final String CONTACTS_COLUMN_ID = "id"; 

   public static final String CONTACTS_COLUMN_NAME = "name"; 

   public static final String CONTACTS_COLUMN_EMAIL = "email"; 

   public static final String CONTACTS_COLUMN_STREET = "street"; 

   public static final String CONTACTS_COLUMN_CITY = "place"; 

   public static final String CONTACTS_COLUMN_PHONE = "phone"; 

   private HashMap hp; 

 

   public DBHelper(Context context) { 

      super(context, DATABASE_NAME , null, 1); 

   } 

 

   @Override 

   public void onCreate(SQLiteDatabase db) { 

      // TODO Auto-generated method stub 

      db.execSQL( 

         "create table contacts " + 

         "(id integer primary key, name text,phone text,email text, street text,place text)" 

      ); 

   } 

 

   @Override 

   public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 

      // TODO Auto-generated method stub 

      db.execSQL("DROP TABLE IF EXISTS contacts"); 

      onCreate(db); 

   } 

 

   public boolean insertContact (String name, String phone, String email, String street,String place) { 

      SQLiteDatabase db = this.getWritableDatabase(); 

      ContentValues contentValues = new ContentValues(); 

      contentValues.put("name", name); 

      contentValues.put("phone", phone); 

      contentValues.put("email", email);	 

      contentValues.put("street", street); 

      contentValues.put("place", place); 

      db.insert("contacts", null, contentValues); 

      return true; 

   } 

    

   public Cursor getData(int id) { 

      SQLiteDatabase db = this.getReadableDatabase(); 

      Cursor res =  db.rawQuery( "select * from contacts where id="+id+"", null ); 

      return res; 

   } 

    

   public int numberOfRows(){ 

      SQLiteDatabase db = this.getReadableDatabase(); 

      int numRows = (int) DatabaseUtils.queryNumEntries(db, CONTACTS_TABLE_NAME); 

      return numRows; 

   } 

    

   public boolean updateContact (Integer id, String name, String phone, String email, String street,String place) { 

      SQLiteDatabase db = this.getWritableDatabase(); 

      ContentValues contentValues = new ContentValues(); 

      contentValues.put("name", name); 

      contentValues.put("phone", phone); 

      contentValues.put("email", email); 

      contentValues.put("street", street); 

      contentValues.put("place", place); 

      db.update("contacts", contentValues, "id = ? ", new String[] { Integer.toString(id) } ); 

      return true; 

   } 

 

   public Integer deleteContact (Integer id) { 

      SQLiteDatabase db = this.getWritableDatabase(); 

      return db.delete("contacts",  

      "id = ? ",  

      new String[] { Integer.toString(id) }); 

   } 

    

   public ArrayList<String> getAllCotacts() { 

      ArrayList<String> array_list = new ArrayList<String>(); 

       

      //hp = new HashMap(); 

      SQLiteDatabase db = this.getReadableDatabase(); 

      Cursor res =  db.rawQuery( "select * from contacts", null ); 

      res.moveToFirst(); 

       

      while(res.isAfterLast() == false){ 

         array_list.add(res.getString(res.getColumnIndex(CONTACTS_COLUMN_NAME))); 

         res.moveToNext(); 

      } 

      return array_list; 

   } 

}      }

Following is the content of the res/layout/activity_main.xml

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

<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"  

   android:paddingLeft="@dimen/activity_horizontal_margin" 

   android:paddingRight="@dimen/activity_horizontal_margin" 

   android:paddingTop="@dimen/activity_vertical_margin" 

   android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity"> 

 

   <TextView 

      android:layout_width="wrap_content" 

      android:layout_height="wrap_content" 

      android:id="@+id/textView" 

      android:layout_alignParentTop="true" 

      android:layout_centerHorizontal="true" 

      android:textSize="30dp" 

      android:text="Data Base" /> 

 

   <TextView 

      android:layout_width="wrap_content" 

      android:layout_height="wrap_content" 

      android:text="Tutorials Point" 

      android:id="@+id/textView2" 

      android:layout_below="@+id/textView" 

      android:layout_centerHorizontal="true" 

      android:textSize="35dp" 

      android:textColor="#ff16ff01" /> 

 

   <ImageView 

      android:layout_width="wrap_content" 

      android:layout_height="wrap_content" 

      android:id="@+id/imageView" 

      android:layout_below="@+id/textView2" 

      android:layout_centerHorizontal="true" 

      android:src="@drawable/logo"/> 

 

   <ScrollView 

      android:layout_width="wrap_content" 

      android:layout_height="wrap_content" 

      android:id="@+id/scrollView" 

      android:layout_below="@+id/imageView" 

      android:layout_alignParentLeft="true" 

      android:layout_alignParentStart="true" 

      android:layout_alignParentBottom="true" 

      android:layout_alignParentRight="true" 

      android:layout_alignParentEnd="true"> 

         

      <ListView 

         android:id="@+id/listView1" 

         android:layout_width="match_parent" 

         android:layout_height="wrap_content" 

         android:layout_centerHorizontal="true" 

         android:layout_centerVertical="true" > 

      </ListView> 

 

   </ScrollView> 

 

</RelativeLayout>

Following is the content of the res/layout/activity_display_contact.xml

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

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android" 

   xmlns:tools="http://schemas.android.com/tools" 

   android:id="@+id/scrollView1" 

   android:layout_width="match_parent" 

   android:layout_height="wrap_content" 

   tools:context=".DisplayContact" > 

 

   <RelativeLayout 

      android:layout_width="match_parent" 

      android:layout_height="370dp" 

      android:paddingBottom="@dimen/activity_vertical_margin" 

      android:paddingLeft="@dimen/activity_horizontal_margin" 

      android:paddingRight="@dimen/activity_horizontal_margin" 

      android:paddingTop="@dimen/activity_vertical_margin"> 

 

      <EditText 

         android:id="@+id/editTextName" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignParentLeft="true" 

         android:layout_marginTop="5dp" 

         android:layout_marginLeft="82dp" 

         android:ems="10" 

         android:inputType="text" > 

      </EditText> 

 

      <EditText 

         android:id="@+id/editTextEmail" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignLeft="@+id/editTextStreet" 

         android:layout_below="@+id/editTextStreet" 

         android:layout_marginTop="22dp" 

         android:ems="10" 

         android:inputType="textEmailAddress" /> 

 

      <TextView 

         android:id="@+id/textView1" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignBottom="@+id/editTextName" 

         android:layout_alignParentLeft="true" 

         android:text="@string/name" 

         android:textAppearance="?android:attr/textAppearanceMedium" /> 

 

      <Button 

         android:id="@+id/button1" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignLeft="@+id/editTextCity" 

         android:layout_alignParentBottom="true" 

         android:layout_marginBottom="28dp" 

         android:onClick="run" 

         android:text="@string/save" /> 

 

      <TextView 

         android:id="@+id/textView2" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignBottom="@+id/editTextEmail" 

         android:layout_alignLeft="@+id/textView1" 

         android:text="@string/email" 

         android:textAppearance="?android:attr/textAppearanceMedium" /> 

 

      <TextView 

         android:id="@+id/textView5" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignBottom="@+id/editTextPhone" 

         android:layout_alignLeft="@+id/textView1" 

         android:text="@string/phone" 

         android:textAppearance="?android:attr/textAppearanceMedium" /> 

 

      <TextView 

         android:id="@+id/textView4" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_above="@+id/editTextEmail" 

         android:layout_alignLeft="@+id/textView5" 

         android:text="@string/street" 

         android:textAppearance="?android:attr/textAppearanceMedium" /> 

 

      <EditText 

         android:id="@+id/editTextCity" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignRight="@+id/editTextName" 

         android:layout_below="@+id/editTextEmail" 

         android:layout_marginTop="30dp" 

         android:ems="10" 

         android:inputType="text" /> 

 

      <TextView 

         android:id="@+id/textView3" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignBaseline="@+id/editTextCity" 

         android:layout_alignBottom="@+id/editTextCity" 

         android:layout_alignParentLeft="true" 

         android:layout_toLeftOf="@+id/editTextEmail" 

         android:text="@string/country" 

         android:textAppearance="?android:attr/textAppearanceMedium" /> 

 

      <EditText 

         android:id="@+id/editTextStreet" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignLeft="@+id/editTextName" 

         android:layout_below="@+id/editTextPhone" 

         android:ems="10" 

         android:inputType="text" > 

 

         <requestFocus /> 

      </EditText> 

 

      <EditText 

         android:id="@+id/editTextPhone" 

         android:layout_width="wrap_content" 

         android:layout_height="wrap_content" 

         android:layout_alignLeft="@+id/editTextStreet" 

         android:layout_below="@+id/editTextName" 

         android:ems="10" 

         android:inputType="phone|text" /> 

 

   </RelativeLayout> 

</ScrollView>

Following is the content of the res/value/string.xml

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

<resources> 

   <string name="app_name">Address Book</string> 

   <string name="action_settings">Settings</string> 

   <string name="hello_world">Hello world!</string> 

   <string name="Add_New">Add New</string> 

   <string name="edit">Edit Contact</string> 

   <string name="delete">Delete Contact</string> 

   <string name="title_activity_display_contact">DisplayContact</string> 

   <string name="name">Name</string> 

   <string name="phone">Phone</string> 

   <string name="email">Email</string> 

   <string name="street">Street</string> 

   <string name="country">City/State/Zip</string> 

   <string name="save">Save Contact</string> 

   <string name="deleteContact">Are you sure, you want to delete it.</string> 

   <string name="yes">Yes</string> 

   <string name="no">No</string> 

</resources>

Following is the content of the res/menu/main_menu.xml

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

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

<menu xmlns:android="http://schemas.android.com/apk/res/android" > 

    

   <item android:id="@+id/item1"  

      android:icon="@drawable/add" 

      android:title="@string/Add_New" > 

   </item> 

    

</menu> 

 

Following is the content of the res/menu/display_contact.xml 

 

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

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 

   package="com.example.sairamkrishna.myapplication" > 

    

   <application 

      android:allowBackup="true" 

      android:icon="@mipmap/ic_launcher" 

      android:label="@string/app_name" 

      android:theme="@style/AppTheme" > 

       

      <activity 

         android:name=".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> 

       

      <activity android:name=".DisplayContact"/> 

       

   </application> 

</manifest>

Preview of application

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MySQL Databases

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