read data from database and show it in GridView in android

Question

how we can read data from database and show them in grid in android? i see codes like this :

public class DataAdapter extends BaseAdapter
{
    Context mContext;
    private String [] id = {"S001","S002","S003","S004","S005","S006","S007"};
    private String [] name={"Rohit","Rahul","Ravi","Amit","Arun","Anil","Kashif"};
    private LayoutInflater mInflater;
    public DataAdapter(Context c)
    {
        mContext=c;
        mInflater = LayoutInflater.from(c);
    }

    public int getCount()
    {
        return id.length;
    }

    public Object getItem(int position)
    {
        return position;
    }

    public long getItemId(int position)
    {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent)
    {
        ViewHolder holder=null;
        // convertView=null;
        if(convertView==null)
        {
            convertView = mInflater.inflate(R.layout.customgrid,
                                                                    parent,false);
            holder = new ViewHolder();
            holder.txtId=(TextView)convertView.findViewById(R.id.txtId);
            holder.txtId.setPadding(100, 10,10 , 10);
            holder.txtName=(TextView)convertView.findViewById(R.id.txtName);
            holder.txtName.setPadding(100, 10, 10, 10);

            if(position==0)
            {                             
                convertView.setTag(holder);
            }
        }
        else
        {
            holder = (ViewHolder) convertView.getTag();
        }
        // holder.txtId.setText(id[position]);
        holder.txtId.setText(id[position]);
        holder.txtName.setText(name[position]);
        return convertView;
    }

    static class ViewHolder
    {
        TextView txtId;
        TextView txtName;
    }
}

//------------main---------------------------------------------

public class GridViewDataActivity extends Activity {
    EditText name;
    GridView gridview;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        gridview = (GridView) findViewById(R.id.gridview);  
        gridview.setAdapter(new DataAdapter(this));
    }
}

same way i want to show data from sqlite DB.

Answer 1

hello this is just demo sample of your need. please check it may help you.

Your Main Activity class

package com.Sqlite_grid_view;

import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.TextView;
import android.widget.Toast;


public class AndroidSQLiteTutorialActivity extends Activity {
    private GridView gridView;
    public static ArrayList<String> ArrayofName = new ArrayList<String>();


    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        DatabaseHandler db = new DatabaseHandler(this);

        /**
         * CRUD Operations
         * */
        // Inserting Contacts
        Log.d("Insert: ", "Inserting ..");
        db.addContact(new Contact("Ravi", "91"));
        db.addContact(new Contact("Srinivas", "99"));
        db.addContact(new Contact("Tommy", "95"));
        db.addContact(new Contact("Karthik", "93"));

        // Reading all contacts
        Log.d("Reading: ", "Reading all contacts..");
        List<Contact> contacts = db.getAllContacts();       

        for (Contact cn : contacts) {
            String log = "Id: "+cn.getID()+" ,Name: " + cn.getName() + " ,Phone: " + cn.getPhoneNumber();
                // Writing Contacts to log
        Log.d("Name: ", log);

        }

        db.getAllContacts();

        gridView = (GridView) findViewById(R.id.gridView1);

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                android.R.layout.simple_list_item_1, ArrayofName);

        gridView.setAdapter(adapter);

        gridView.setOnItemClickListener(new OnItemClickListener() {
            public void onItemClick(AdapterView<?> parent, View v,
                int position, long id) {
               Toast.makeText(getApplicationContext(),
                ((TextView) v).getText(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}

Contact java class

package com.Sqlite_grid_view;

import java.util.ArrayList;

public class Contact {



    //private variables
    int _id;
    String _name;
    String _phone_number;

    // Empty constructor
    public Contact(){

    }
    // constructor
    public Contact(int id, String name, String _phone_number){
        this._id = id;
        this._name = name;
        this._phone_number = _phone_number;
    }

    // constructor
    public Contact(String name, String _phone_number){
        this._name = name;
        this._phone_number = _phone_number;
    }
    // getting ID
    public int getID(){
        return this._id;
    }

    // setting id
    public void setID(int id){
        this._id = id;
    }

    // getting name
    public String getName(){
        return this._name;
    }

    // setting name
    public void setName(String name){
        this._name = name;
    }

    // getting phone number
    public String getPhoneNumber(){
        return this._phone_number;
    }

    // setting phone number
    public void setPhoneNumber(String phone_number){
        this._phone_number = phone_number;
    }
}

Database Helper Class:

package com.Sqlite_grid_view;

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 {

    // All Static variables
    // Database Version
    private static final int DATABASE_VERSION = 1;

    // Database Name
    private static final String DATABASE_NAME = "contactsManager";

    // Contacts table name
    private static final String TABLE_CONTACTS = "contacts";

    // Contacts Table Columns names
    private static final String KEY_ID = "id";
    private static final String KEY_NAME = "name";
    private static final String KEY_PH_NO = "phone_number";

    public DatabaseHandler(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

    // Creating Tables
    @Override
    public void onCreate(SQLiteDatabase db) {
        String CREATE_CONTACTS_TABLE = "CREATE TABLE " + TABLE_CONTACTS + "("
                + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
                + KEY_PH_NO + " TEXT" + ")";
        db.execSQL(CREATE_CONTACTS_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_CONTACTS);

        // Create tables again
        onCreate(db);
    }

    /**
     * All CRUD(Create, Read, Update, Delete) Operations
     */

    // Adding new contact
    void addContact(Contact contact) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_NAME, contact.getName()); // Contact Name
        values.put(KEY_PH_NO, contact.getPhoneNumber()); // Contact Phone

        // Inserting Row
        db.insert(TABLE_CONTACTS, null, values);
        db.close(); // Closing database connection
    }

    // Getting single contact
    Contact getContact(int id) {
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID,
                KEY_NAME, KEY_PH_NO }, KEY_ID + "=?",
                new String[] { String.valueOf(id) }, null, null, null, null);
        if (cursor != null)
            cursor.moveToFirst();

        Contact contact = new Contact(Integer.parseInt(cursor.getString(0)),
                cursor.getString(1), cursor.getString(2));
        // return contact
        return contact;
    }

    // Getting All Contacts
    public List<Contact> getAllContacts() {
        List<Contact> contactList = new ArrayList<Contact>();
        // Select All Query
        String selectQuery = "SELECT  * FROM " + TABLE_CONTACTS;

        SQLiteDatabase db = this.getWritableDatabase();
        Cursor cursor = db.rawQuery(selectQuery, null);

        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                Contact contact = new Contact();
                contact.setID(Integer.parseInt(cursor.getString(0)));
                contact.setName(cursor.getString(1));
                contact.setPhoneNumber(cursor.getString(2));

                String name = cursor.getString(1) +"\n"+ cursor.getString(2);
                AndroidSQLiteTutorialActivity.ArrayofName.add(name);
                // Adding contact to list
                contactList.add(contact);
            } while (cursor.moveToNext());
        }

        // return contact list
        return contactList;
    }

    // Updating single contact
    public int updateContact(Contact contact) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(KEY_NAME, contact.getName());
        values.put(KEY_PH_NO, contact.getPhoneNumber());

        // updating row
        return db.update(TABLE_CONTACTS, values, KEY_ID + " = ?",
                new String[] { String.valueOf(contact.getID()) });
    }

    // Deleting single contact
    public void deleteContact(Contact contact) {
        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_CONTACTS, KEY_ID + " = ?",
                new String[] { String.valueOf(contact.getID()) });
        db.close();
    }


    // Getting contacts Count
    public int getContactsCount() {
        String countQuery = "SELECT  * FROM " + TABLE_CONTACTS;
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(countQuery, null);
        cursor.close();

        // return count
        return cursor.getCount();
    }

}

your layout file with grid view : main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <GridView android:layout_height="wrap_content" android:id="@+id/gridView1"
        android:layout_width="match_parent" android:numColumns="3"></GridView>
</LinearLayout>

in last your manifest file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.Sqlite_grid_view"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="4" />

    <application
        android:icon="@drawable/icon"
        android:label="sqlite test" >
        <activity
            android:label="@string/app_name"
            android:name=".AndroidSQLiteTutorialActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />

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

Best Luck!!

Answer 2

You should use CursorLoader and SimpleCursorAdapter. This is the most efficient way of doing this kind of things.

You can read about loaders usage here and see some simple example here.

The only thing you may have some difficulties with is that default CursorLoader can query cursor only from ContentProvider, but you can use SimpleCursorLoader mentioned in this question