SQLite is an open-source lightweight relational database management system (RDBMS) to perform database operations, such as storing, updating, retrieving data from the database. To know more about SQLite, check this SQLite Tutorial with Examples.
Generally, in our android applications Shared Preferences, Internal Storage and External Storage options are useful to store and maintain a small amount of data. In case, if we want to deal with large amounts of data, then the SQLite database is the preferable option to store and maintain the data in a structured format.
To know more about using SQLite Database in android applications, check this Android SQLite Database Tutorial with Examples.
Now we will see how to create & insert data into SQLite Database and how to retrieve and show the data in custom listview in android application with examples.
Following is the example of creating the SQLite database, insert and show the details from the SQLite database into an android listview using the SQLiteOpenHelper class.
Create a new android application using android studio and give names as SQLiteExample. In case if you are not aware of creating an app in android studio check this article Android Hello World App.
Once we create an application, create a class file DbHandler.java in \java\com.tutlane.sqliteexample path to implement SQLite database related activities for that right-click on your application folder à Go to New à select Java Class and give name as DbHandler.java.
Once we create a new class file DbHandler.java, open it and write the code like as shown below
package com.tutlane.sqliteexample;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import java.util.ArrayList;
import java.util.HashMap;
/**
* Created by tutlane on 06-01-2018.
*/
public class DbHandler extends SQLiteOpenHelper private static final int DB_VERSION = 1 ;
private static final String DB_NAME = "usersdb" ;
private static final String TABLE_Users = "userdetails" ;
private static final String KEY_ID = "id" ;
private static final String KEY_NAME = "name" ;
private static final String KEY_LOC = "location" ;
private static final String KEY_DESG = "designation" ;
public DbHandler(Context context) super (context, DB_NAME , null , DB_VERSION );
>
@Override
public void onCreate(SQLiteDatabase db) String CREATE_TABLE = "CREATE TABLE " + TABLE_Users + "("
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + KEY_NAME + " TEXT,"
+ KEY_LOC + " TEXT,"
+ KEY_DESG + " TEXT" + ")" ;
db.execSQL(CREATE_TABLE);
>
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) // Drop older table if exist
db.execSQL( "DROP TABLE IF EXISTS " + TABLE_Users );
// Create tables again
onCreate(db);
>
// **** CRUD (Create, Read, Update, Delete) Operations ***** //
// Adding new User Details
void insertUserDetails(String name, String location, String designation) //Get the Data Repository in write mode
SQLiteDatabase db = this .getWritableDatabase();
//Create a new map of values, where column names are the keys
ContentValues cValues = new ContentValues();
cValues.put( KEY_NAME , name);
cValues.put( KEY_LOC , location);
cValues.put( KEY_DESG , designation);
// Insert the new row, returning the primary key value of the new row
long newRowId = db.insert( TABLE_Users , null , cValues);
db.close();
>
// Get User Details
public ArrayList> GetUsers() SQLiteDatabase db = this .getWritableDatabase();
ArrayList> userList = new ArrayList<>();
String query = "SELECT name, location, designation FROM " + TABLE_Users ;
Cursor cursor = db.rawQuery(query, null );
while (cursor.moveToNext()) HashMap user = new HashMap<>();
user.put( "name" ,cursor.getString(cursor.getColumnIndex( KEY_NAME )));
user.put( "designation" ,cursor.getString(cursor.getColumnIndex( KEY_DESG )));
user.put( "location" ,cursor.getString(cursor.getColumnIndex( KEY_LOC )));
userList.add(user);
>
return userList;
>
// Get User Details based on userid
public ArrayList> GetUserByUserId( int userid) SQLiteDatabase db = this .getWritableDatabase();
ArrayList> userList = new ArrayList<>();
String query = "SELECT name, location, designation FROM " + TABLE_Users ;
Cursor cursor = db.query( TABLE_Users , new String[]< KEY_NAME , KEY_LOC , KEY_DESG >, KEY_ID + "=?" , new String[], null , null , null , null );
if (cursor.moveToNext()) HashMap user = new HashMap<>();
user.put( "name" ,cursor.getString(cursor.getColumnIndex( KEY_NAME )));
user.put( "designation" ,cursor.getString(cursor.getColumnIndex( KEY_DESG )));
user.put( "location" ,cursor.getString(cursor.getColumnIndex( KEY_LOC )));
userList.add(user);
>
return userList;
>
// Delete User Details
public void DeleteUser( int userid) SQLiteDatabase db = this .getWritableDatabase();
db.delete( TABLE_Users , KEY_ID + " = ?" , new String[]);
db.close();
>
// Update User Details
public int UpdateUserDetails(String location, String designation, int id) SQLiteDatabase db = this .getWritableDatabase();
ContentValues cVals = new ContentValues();
cVals.put( KEY_LOC , location);
cVals.put( KEY_DESG , designation);
int count = db.update( TABLE_Users , cVals, KEY_ID + " = ?" , new String[]);
return count;
>
>
If you observe above code, we implemented all SQLite Database related activities to perform CRUD operations in android application.
Now open activity_main.xml file from \res\layout folder path and write the code like as shown below.
< LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
android :orientation= "vertical" android :layout_width= "match_parent"
android :layout_height= "match_parent" >
< TextView
android :id= "@+id/fstTxt"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_marginLeft= "100dp"
android :layout_marginTop= "150dp"
android :text= "Name" />
< EditText
android :id= "@+id/txtName"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_marginLeft= "100dp"
android :ems= "10" />
< TextView
android :id= "@+id/secTxt"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :text= "Location"
android :layout_marginLeft= "100dp" />
< EditText
android :id= "@+id/txtLocation"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_marginLeft= "100dp"
android :ems= "10" />
< TextView
android :id= "@+id/thirdTxt"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :text= "Designation"
android :layout_marginLeft= "100dp" />
< EditText
android :id= "@+id/txtDesignation"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_marginLeft= "100dp"
android :ems= "10" />
< Button
android :id= "@+id/btnSave"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_marginLeft= "100dp"
android :text= "Save" />
Now we will create another layout resource file details.xml in \res\layout path to show the details in custom listview from SQLite Database for that right click on your layout folder à Go to New à select Layout Resource File and give name as details.xml.
Once we create a new layout resource file details.xml, open it and write the code like as shown below
< LinearLayout xmlns: android = "http://schemas.android.com/apk/res/android"
android :layout_width= "fill_parent"
android :layout_height= "fill_parent"
android :orientation= "vertical" >
< ListView
android :id= "@+id/user_list"
android :layout_width= "fill_parent"
android :layout_height= "wrap_content"
android :dividerHeight= "1dp" />
< Button
android :id= "@+id/btnBack"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_gravity= "center"
android :layout_marginTop= "20dp"
android :text= "Back" />
Create an another layout file (list_row.xml) in /res/layout folder to show the data in listview, for that right click on layout folder à add new Layout resource file à Give name as list_row.xml and write the code like as shown below.
< RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android"
android :layout_width= "fill_parent"
android :layout_height= "wrap_content"
android :orientation= "horizontal"
android :padding= "5dip" >
< TextView
android :id= "@+id/name"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :textStyle= "bold"
android :textSize= "17dp" />
< TextView
android :id= "@+id/designation"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_below= "@id/name"
android :layout_marginTop= "7dp"
android :textColor= "#343434"
android :textSize= "14dp" />
< TextView
android :id= "@+id/location"
android :layout_width= "wrap_content"
android :layout_height= "wrap_content"
android :layout_alignBaseline= "@+id/designation"
android :layout_alignBottom= "@+id/designation"
android :layout_alignParentRight= "true"
android :textColor= "#343434"
android :textSize= "14dp" />
Now open your main activity file MainActivity.java from \java\com.tutlane.sqliteexample path and write the code like as shown below
package com.tutlane.sqliteexample;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity EditText name , loc , desig ;
Button saveBtn ;
Intent intent ;
@Override
protected void onCreate(Bundle savedInstanceState) super .onCreate(savedInstanceState);
setContentView(R.layout. activity_main );
name = (EditText)findViewById(R.id. txtName );
loc = (EditText)findViewById(R.id. txtLocation );
desig = (EditText)findViewById(R.id. txtDesignation );
saveBtn = (Button)findViewById(R.id. btnSave );
saveBtn .setOnClickListener( new View.OnClickListener() @Override
public void onClick(View v) String username = name .getText().toString()+ " \n " ;
String location = loc .getText().toString();
String designation = desig .getText().toString();
DbHandler dbHandler = new DbHandler(MainActivity. this );
dbHandler.insertUserDetails(username,location,designation);
intent = new Intent(MainActivity. this ,DetailsActivity. class );
startActivity( intent );
Toast.makeText(getApplicationContext(), "Details Inserted Successfully" ,Toast. LENGTH_SHORT ).show();
>
>);
>
>
If you observe above code, we are taking entered user details and inserting into SQLite database and redirecting the user to another activity.
Now we will create another activity file DetailsActivity.java in \java\com.tutlane.sqliteexample path to show details from the SQLite database. For that, right-click on your application folder à Go to New à select Java Class and give name as DetailsActivity.java.
Once we create a new activity file DetailsActivity.java, open it and write the code like as shown below
package com.tutlane.sqliteexample;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import java.util.ArrayList;
import java.util.HashMap;
/**
* Created by tutlane on 05-01-2018.
*/
public class DetailsActivity extends AppCompatActivity Intent intent ;
@Override
protected void onCreate(Bundle savedInstanceState) super .onCreate(savedInstanceState);
setContentView(R.layout. details );
DbHandler db = new DbHandler( this );
ArrayList> userList = db.GetUsers();
ListView lv = (ListView) findViewById(R.id. user_list );
ListAdapter adapter = new SimpleAdapter(DetailsActivity. this , userList, R.layout. list_row , new String[]< "name" , "designation" , "location" >, new int []);
lv.setAdapter(adapter);
Button back = (Button)findViewById(R.id. btnBack );
back.setOnClickListener( new View.OnClickListener() @Override
public void onClick(View v) intent = new Intent(DetailsActivity. this ,MainActivity. class );
startActivity( intent );
>
>);
>
>
If you observe above code, we are getting the details from SQLite database and binding the details to android listview. Now we need to add this newly created activity in AndroidManifest.xml file in like as shown below.
If you observe above example, we are saving entered details in SQLite database and redirecting the user to another activity file (DetailsActivity.java) to show the users details and added all the activities in AndroidManifest.xml file.
When we run the above example in the android emulator we will get a result like as shown below.
If you observe the above result, the entered user details are storing in the SQLite database and redirecting the user to another activity file to show the user details from SQLite Database in listview. After that, if we click on the Back button, it will redirect the user to login page.
This is how we can get the data from the SQLite database and bind it to custom listview in android applications based on our requirements.