Read data from a database and show it in a gridview in android

Question

how can we read data from a database and display it in a 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)); } } 

just as I want to show data from sqlite DB.

Answer 1

Hi, this is just a demo of your need. please check that this can 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(); } }); } } 

Refer to 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 a 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 the last 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 effective way to do such things.

You can read about using bootloaders here and see a simple example.

The only thing you may encounter is that by default CursorLoader can only request the cursor from the ContentProvider , but you can use the SimpleCursorLoader mentioned in this question