How to read SQLite by cursor and display in textview

How to read SQLite by cursor and display in textview - java

How to read and display "email" and "address" in HomeAcitivity TextView.
The database designed to be store only 1 row of data.
DatabaseHandler.java
package com.example.androidjhfong.library;
import java.util.HashMap;
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 = "android_database";
// Table name
private static final String TABLE_LOGIN = "login";
// Login Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_EMAIL = "email";
private static final String KEY_UID = "uid";
private static final String KEY_ADDRESS = "address";
private static final String KEY_PHONE = "phone";
private static final String KEY_CREATED_AT = "created_at";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LOGIN + "("
+ KEY_ID + " INTEGER PRIMARY KEY,"
+ KEY_NAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE,"
+ KEY_UID + " TEXT,"
+ KEY_ADDRESS + " TEXT,"
+ KEY_PHONE + " TEXT,"
+ KEY_CREATED_AT + " TEXT" + ")";
db.execSQL(CREATE_LOGIN_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_LOGIN);
// Create tables again
onCreate(db);
}
/**
* Storing user details in database
* */
public void addUser(String name, String email, String uid, String address, String phone, String created_at) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, name); // Name
values.put(KEY_EMAIL, email); // Email
values.put(KEY_UID, uid); // Email
values.put(KEY_ADDRESS, address); // Address
values.put(KEY_PHONE, phone); // phone
values.put(KEY_CREATED_AT, created_at); // Created At
// Inserting Row
db.insert(TABLE_LOGIN, null, values);
db.close(); // Closing database connection
}
/**
* Getting user data from database
* */
public HashMap<String, String> getUserDetails(){
HashMap<String,String> user = new HashMap<String,String>();
String selectQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
if(cursor.getCount() > 0){
user.put("name", cursor.getString(1));
user.put("email", cursor.getString(2));
user.put("uid", cursor.getString(3));
user.put("address", cursor.getString(4));
user.put("phone", cursor.getString(5));
user.put("created_at", cursor.getString(6));
}
cursor.close();
db.close();
// return user
return user;
}
/**
* Getting user login status
* return true if rows are there in table
* */
public int getRowCount() {
String countQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
/**
* Re crate database
* Delete all tables and create them again
* */
public void resetTables(){
SQLiteDatabase db = this.getWritableDatabase();
// Delete All Rows
db.delete(TABLE_LOGIN, null, null);
db.close();
}
/**
* Getting product status
**/
public String getData() {
String username;
String getdata = "SELECT name FROM " + TABLE_LOGIN;
//String[] columns = new String[]{ KEY_ID, KEY_NAME, KEY_ADDRESS, KEY_PHONE};
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(getdata, null);
cursor.moveToFirst();
username=cursor.getString(cursor.getColumnIndex("name"));
cursor.close();
db.close();
return username;
}
}
how to display the retrieve the data and display in HomeActivity correctly?
HomeActivity
public class HomeActivity extends Activity implements OnItemSelectedListener{
TextView inputname
TextView inputemail;
TextView inputaddress;
Button btnPurchase;
// JSON Response node names
private static String KEY_SUCCESS = "success";
private static String KEY_ADDRESS = "address";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.Home);
inputname= (TextView) findViewById(R.id.qrpurchaseitem);
inputaddress = (TextView) findViewById(R.id.qrtextpurchaseaddress);
inputemail = (TextView) findViewById(R.id.qrtextpurchasecomment);
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
HashMap<String, String> key = db.getUserDetails();
String text= DatabaseHandler.getUserDetails();
}

in your HomeActivty add this both line
String email=db.getEmail()
String address=db.getAddress();
Now then you can use below method in you Database Handler class, just change variable name from below methods
public String getStartBal() {
Cursor cr=ourDatabase.rawQuery("SELECT "+KEY_START_BAL+" FROM "+DB_TABLE,null);
String sum="";
for(cr.moveToFirst();!cr.isAfterLast();cr.moveToNext()){
sum=cr.getString(cr.getColumnIndex(KEY_START_BAL));
}
cr.close();
return sum;
}

Related

multiple tables in android

I want to use two tables in my SQLite database but when I try to read the second table my app crashes.
I have a table for the items in a storage and another table for the employees of the storage.
Here is my database class:
public class Database extends SQLiteOpenHelper {
protected static final String DATABASE_NAME = "Storage";
protected static final String KEY_ID = "id";
protected static final String KEY_DESCRIPTION = "description";
protected static final String KEY_CATEGORY = "category";
protected static final String KEY_ORIGIN = "origin";
protected static final String KEY_DATE = "date";
protected static final String KEY_BRAND = "brand";
protected static final String TAB_NAME = "items";
protected static final String KEY_ID2 = "id2";
protected static final String KEY_SURNAME = "surname";
protected static final String KEY_NAME = "name";
protected static final String KEY_USERNAME = "username";
protected static final String KEY_PASSWORD = "password";
protected static final String TAB_NAME2 = "employees";
protected static final int VERSION = 1;
public Database(Context context) {
super(context, DATABASE_NAME, null, VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_ITEMS_TABLE = "CREATE TABLE " + TAB_NAME + " ("
+ KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_DESCRIPTION + " TEXT, "
+ KEY_CATEGORY + " TEXT, "
+ KEY_ORIGIN + " TEXT, "
+ KEY_DATE + " TEXT, "
+ KEY_BRAND + " TEXT)";
String CREATE_DIPENDENTI_TABLE = "CREATE TABLE " + TAB_NAME2 + " ("
+ KEY_ID2 + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ KEY_SURNAME + " TEXT, "
+ KEY_NAME + " TEXT, "
+ KEY_USERNAME + " TEXT, "
+ KEY_PASSWORD + " TEXT)";
db.execSQL(CREATE_ITEMS_TABLE);
db.execSQL(CREATE_DIPENDENTI_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TAB_NAME);
db.execSQL("DROP TABLE IF EXISTS " + TAB_NAME2);
this.onCreate(db);
}
public void Add(String des, String cat, String pro, String data, String brand) {
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_DESCRIPTION, des);
contentValues.put(KEY_CATEGORY, cat);
contentValues.put(KEY_ORIGIN, pro);
contentValues.put(KEY_DATE, data);
contentValues.put(KEY_BRAND, brand);
sqLiteDatabase.insert(TAB_NAME,null, contentValues);
sqLiteDatabase.close();
}
public void Add(String cog, String nom, String user, String pass) {
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(KEY_SURNAME, cog);
contentValues.put(KEY_NAME, nom);
contentValues.put(KEY_USERNAME, user);
contentValues.put(KEY_PASSWORD, pass);
sqLiteDatabase.insert(TAB_NAME2,null, contentValues);
sqLiteDatabase.close();
}
public Cursor getInfo() {
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM " + TAB_NAME + ";";
return sqLiteDatabase.rawQuery(query, null);
}
public ArrayList getInfoDip() {
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
ArrayList<String> al=new ArrayList<>();
Cursor cursor= sqLiteDatabase.rawQuery("SELECT * FROM " +TAB_NAME2, null);
cursor.moveToFirst();
while (!cursor.isAfterLast()){
al.add(cursor.getString(cursor.getColumnIndex("surname")));
al.add(cursor.getString(cursor.getColumnIndex("name")));
al.add(cursor.getString(cursor.getColumnIndex("username")));
al.add(cursor.getString(cursor.getColumnIndex("password")));
cursor.moveToNext();
}
return al;
}
public void Modify(int cod,String des, String cat, String pro, String dat, String bran){
SQLiteDatabase db = this.getWritableDatabase();
if(!des.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET description = "+"'"+des+"' "+ "WHERE id = "+"'"+cod+"'");
if(!cat.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET categoria = "+"'"+cat+"' "+ "WHERE id = "+"'"+cod+"'");
if(!pro.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET origin = "+"'"+pro+"' "+ "WHERE id = "+"'"+cod+"'");
if(!dat.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET date = "+"'"+dat+"' "+ "WHERE id = "+"'"+cod+"'");
if(!bran.isEmpty())
db.execSQL("UPDATE "+TAB_NAME+" SET brand = "+"'"+bran+"' "+ "WHERE id = "+"'"+cod+"'");
}
public void Modify(int cod, String cog, String nom, String user, String pass){
SQLiteDatabase db = this.getWritableDatabase();
if(!cog.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET surname = "+"'"+cog+"' "+ "WHERE id2 = "+"'"+cod+"'");
if(!nom.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET name = "+"'"+nom+"' "+ "WHERE id2 = "+"'"+cod+"'");
if(!user.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET username = "+"'"+user+"' "+ "WHERE id2 = "+"'"+cod+"'");
if(!pass.isEmpty())
db.execSQL("UPDATE "+TAB_NAME2+" SET password = "+"'"+pass+"' "+ "WHERE id2 = "+"'"+cod+"'");
}
public void Delete(int cod){
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM "+TAB_NAME+" WHERE id= "+"'"+cod+"'");
}
public void DeleteDip(int cod){
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("DELETE FROM "+TAB_NAME2+" WHERE id2= "+"'"+cod+"'");
}
public Cursor Search(int cod){
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM " + TAB_NAME + " WHERE id = "+"'"+cod+"';";
return sqLiteDatabase.rawQuery(query, null);
}
public Cursor Search(String des){
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT * FROM " + TAB_NAME + " WHERE description = "+"'"+des+"';";
return sqLiteDatabase.rawQuery(query, null);
}
public void DeleteAll() {
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("delete from " + TAB_NAME);
}
}
and here is the activity where I try to get the ArrayList with the data:
private Database db= new Database(this);
private ArrayList<String> al=new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user);
db.Add("admin","admin","admin","admin");
al.addAll(db.getInfoDip());
But when I try to put the data in the ArrayList the app crashes. Can anyone help me out?

Well so far, how I learned that the best practice for formating queries is to use String.format function. Here your example:
String query = "SELECT * FROM " + TAB_NAME + ";";
Best practice:
String query = String.format("SELECT * FROM %s", TAB_NAME);
So let's get to the getInfoDip method, you should try this:
public List<ContentValues> getInfoDip() {
SQLiteDatabase sqLiteDatabase = this.getReadableDatabase();
String query = String.format("SELECT * FROM %s", TAB_NAME2);
Cursor res = db.rawQuery(query, null);
res.moveToFirst();
List<ContentValues> list = new ArrayList<>(res.getCount());
while (!res.isAfterLast()){
String surname = res.getString(res.getColumnIndex(KEY_SURNAME));
String name = res.getString(res.getColumnIndex(KEY_NAME));
String username = res.getString(res.getColumnIndex(KEY_USERNAME));
String password = res.getString(res.getColumnIndex(KEY_PASSWORD));
list.add(new ContentValues(surname, name, username, password));
res.moveToNext();
}
return list;
}
Here is my whole SQLite test program, check out maybe it helps you:
package com.example.vezba09;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import androidx.annotation.Nullable;
import java.util.ArrayList;
import java.util.List;
public class Database extends SQLiteOpenHelper {
private static final String DATABASE_FILE_NAME = "contact_database";
public Database(#Nullable Context context) {
super(context, DATABASE_FILE_NAME, null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
String query = String.format(
"CREATE TABLE IF NOT EXISTS %s (%s INTEGER PRIMARY KEY AUTOINCREMENT, %s TEXT, %s TEXT, %s TEXT)",
ContactModel.TABLE_NAME,
ContactModel.COLUMN_CONTACT_ID,
ContactModel.COLUMN_CONTACT_NAME,
ContactModel.COLUMN_CONTACT_EMAIL,
ContactModel.COLUMN_CONTACT_PHONE
);
db.execSQL(query);
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
String query = String.format("DROP TABLE IF EXISTS %s", ContactModel.TABLE_NAME);
db.execSQL(query);
onCreate(db);
}
//Dodavanje kontakta
public void addContact(String name, String email, String phone) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(ContactModel.COLUMN_CONTACT_NAME, name);
cv.put(ContactModel.COLUMN_CONTACT_EMAIL, email);
cv.put(ContactModel.COLUMN_CONTACT_PHONE, phone);
db.insert(ContactModel.TABLE_NAME, null, cv);
}
//Izmena
public void editContact(int contactId, String name, String email, String phone) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(ContactModel.COLUMN_CONTACT_NAME, name);
cv.put(ContactModel.COLUMN_CONTACT_EMAIL, email);
cv.put(ContactModel.COLUMN_CONTACT_PHONE, phone);
db.update(ContactModel.TABLE_NAME,
cv,
ContactModel.COLUMN_CONTACT_ID + "=?",
new String[]{String.valueOf(contactId)});
}
public int deleteContact(int contactId) {
SQLiteDatabase db = this.getWritableDatabase();
return db.delete(ContactModel.TABLE_NAME,
ContactModel.COLUMN_CONTACT_ID + "=?",
new String[]{String.valueOf(contactId)});
}
public ContactModel getContactById(int contactId) {
SQLiteDatabase db = this.getReadableDatabase();
String query = String.format("SELECT * FROM %s WHERE %s = ?",
ContactModel.TABLE_NAME,
ContactModel.COLUMN_CONTACT_ID);
Cursor res = db.rawQuery(query, new String[] {String.valueOf(contactId)});
if(res.moveToFirst()) {
String name = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_NAME));
String email = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_EMAIL));
String phone = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_PHONE));
return new ContactModel(contactId, name, email, phone);
}
else {
return null;
}
}
public List<ContactModel> getAllContacts() {
SQLiteDatabase db = this.getReadableDatabase();
String query = String.format("SELECT * FROM %s", ContactModel.TABLE_NAME);
Cursor res = db.rawQuery(query, null);
res.moveToFirst();
List<ContactModel> list = new ArrayList<>(res.getCount());
while(!res.isAfterLast()) {
int contactId = res.getInt(res.getColumnIndex(ContactModel.COLUMN_CONTACT_ID));
String name = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_NAME));
String email = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_EMAIL));
String phone = res.getString(res.getColumnIndex(ContactModel.COLUMN_CONTACT_PHONE));
list.add(new ContactModel(contactId, name, email, phone));
res.moveToNext();
}
return list;
}
}
Try this and feel free to ask more questions :)
Best regards, Sanady

NullPointerException at this.getReadableDatabase();

Heyhey :)
I looked at several Questions to the same topic, but I found no solution to my problem.
A NullPointerException at this.getReadableDatabase(); appears...
Here's my Code:
public class DatabaseHandler extends SQLiteOpenHelper {
public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "TODO_APP";
/*--------------------------- TABLE ITEMS START ---------------------------*/
private static final String TABLE_ITEMS = "items";
private static String KEY_ID_ITEMS = "id_items";
private static final String KEY_CATEGORY_ITEMS = "category";
private static final String KEY_DATETIME_ITEMS = "datetime";
private static String KEY_NAME_ITEMS = "name";
private static final String KEY_DESCRIPTION_ITEMS = "description";
private static final String KEY_ALARM_ITEMS = "alarm";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
// create table ITEMS
String CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS + "("
+ KEY_ID_ITEMS + " INTEGER PRIMARY KEY," + KEY_CATEGORY_ITEMS
+ " INTEGER," + KEY_DATETIME_ITEMS
+ " TIMESTAMP DEFAULT CURRENT_TIMESTAMP," + KEY_NAME_ITEMS
+ " TEXT," + KEY_DESCRIPTION_ITEMS + " TEXT," + KEY_ALARM_ITEMS
+ " INTEGER" + ");";
db.execSQL(CREATE_ITEMS_TABLE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_ITEMS);
// Create tables again
this.onCreate(db);
}
public void addItem(DB_Item item) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_CATEGORY_ITEMS, item.getCategory());
values.put(KEY_NAME_ITEMS, item.getName());
values.put(KEY_DESCRIPTION_ITEMS, item.getDescription());
values.put(KEY_ALARM_ITEMS, item.getAlarm());
// Inserting Row
db.insert(TABLE_ITEMS, null, values);
db.close(); // Closing database connection
}
public DB_Item getItem(String name) {
//!!!!! Here is one problem !!!!!
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.query(TABLE_ITEMS, new String[] { KEY_ID_ITEMS,
KEY_CATEGORY_ITEMS, KEY_DATETIME_ITEMS, KEY_NAME_ITEMS,
KEY_DESCRIPTION_ITEMS, KEY_ALARM_ITEMS },
KEY_NAME_ITEMS = " = ?", new String[] { String.valueOf(name) },
null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
// DB_Item (int category, String name, String description, int
// alarm)
DB_Item item = new DB_Item(cursor.getInt(1), cursor.getString(3),
cursor.getString(4), cursor.getInt(5));
return item;
}
public List<DB_Item> getAllItems() {
List<DB_Item> itemList = new ArrayList<DB_Item>();
// SELECT ALL
String selectQuery = "SELECT * FROM " + TABLE_ITEMS;
//!!!!!!!!!! here is the other Problem
SQLiteDatabase database = this.getWritableDatabase();
Cursor cursor = database.rawQuery(selectQuery, null);
// go through all rows and then adding to list
if (cursor.moveToFirst()) {
do {
DB_Item item = new DB_Item();
item.setCategory(Integer.parseInt(cursor.getString(0)));
// TODO
// adding to list
itemList.add(item);
} while (cursor.moveToNext());
}
return itemList;
}
[and so on, didn't copy the whole code]
Hope you can help me...
The error appears definitely at SQLiteDatabase db = this.getReadableDatabase();
Output:
09-03 08:34:17.863: E/AndroidRuntime(7074): java.lang.RuntimeException: Unable to start activity ComponentInfo{todo.todo_list/todo.view.StartApp}: java.lang.NullPointerException
09-03 08:34:17.863: E/AndroidRuntime(7074): at todo.database.DatabaseHandler.getAllItems(DatabaseHandler.java:144)
09-03 08:34:17.863: E/AndroidRuntime(7074): at todo.helper.SortItems.sortItemsCategory(SortItems.java:16)
09-03 08:34:17.863: E/AndroidRuntime(7074): at todo.view.StartApp.onCreate(StartApp.java:36)

chnage you class to something like this:
package com.mhp.example;
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 {
/*--------------------------- TABLE ITEMS START ---------------------------*/
private static final String TABLE_ITEMS = "items";
private static String KEY_ID_ITEMS = "id_items";
private static final String KEY_CATEGORY_ITEMS = "category";
private static final String KEY_DATETIME_ITEMS = "datetime";
private static String KEY_NAME_ITEMS = "name";
private static final String KEY_DESCRIPTION_ITEMS = "description";
private static final String KEY_ALARM_ITEMS = "alarm";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "dbname";
private static final int DATABASE_VERSION = 1;
tring CREATE_ITEMS_TABLE = "CREATE TABLE " + TABLE_ITEMS + "("
+ KEY_ID_ITEMS + " INTEGER PRIMARY KEY," + KEY_CATEGORY_ITEMS
+ " INTEGER," + KEY_DATETIME_ITEMS
+ " TIMESTAMP DEFAULT CURRENT_TIMESTAMP," + KEY_NAME_ITEMS
+ " TEXT," + KEY_DESCRIPTION_ITEMS + " TEXT," + KEY_ALARM_ITEMS
+ " INTEGER" + ");";
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(CREATE_ITEMS_TABLE);
} 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();
}
public void addItem(DB_Item item) {
ContentValues values = new ContentValues();
values.put(KEY_CATEGORY_ITEMS, item.getCategory());
values.put(KEY_NAME_ITEMS, item.getName());
values.put(KEY_DESCRIPTION_ITEMS, item.getDescription());
values.put(KEY_ALARM_ITEMS, item.getAlarm());
// Inserting Row
db.insert(TABLE_ITEMS, null, values);
}
public DB_Item getItem(String name) {
Cursor cursor = db.query(TABLE_ITEMS, new String[] { KEY_ID_ITEMS,
KEY_CATEGORY_ITEMS, KEY_DATETIME_ITEMS, KEY_NAME_ITEMS,
KEY_DESCRIPTION_ITEMS, KEY_ALARM_ITEMS },
KEY_NAME_ITEMS = " = ?", new String[] { String.valueOf(name) },
null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
// DB_Item (int category, String name, String description, int
// alarm)
DB_Item item = new DB_Item(cursor.getInt(1), cursor.getString(3),
cursor.getString(4), cursor.getInt(5));
return item;
}
public List<DB_Item> getAllItems() {
List<DB_Item> itemList = new ArrayList<DB_Item>();
// SELECT ALL
String selectQuery = "SELECT * FROM " + TABLE_ITEMS;
Cursor cursor = db.rawQuery(selectQuery, null);
// go through all rows and then adding to list
if (cursor.moveToFirst()) {
do {
DB_Item item = new DB_Item();
item.setCategory(Integer.parseInt(cursor.getString(0)));
// TODO
// adding to list
itemList.add(item);
} while (cursor.moveToNext());
}
return itemList;
}
}
NOTE: when you create object from DBAdapter,you should open() db and after your work close() it.
DBAdapter db = new DBAdapter(contex);
db.open();
//do you work
db.close();

Just use getReadableDatabase() without this.

No data retrieved if open sqlite more than once

When I add data into sqlite and open it for the first time, the data inside will be displayed. However, if I try opening it again nothing will show up even though there is data inside. May I know what is the problem?
Class that performs the activity:
public class Watchlist extends ListActivity {
private ArrayList<String> results = new ArrayList<String>();
private String tableName = DatabaseHandler.TABLE_ITEM;
private SQLiteDatabase newDB;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
openAndQueryDatabase();
displayResultList();
}
private void displayResultList() {
TextView tView = new TextView(this);
tView.setText("This data is retrieved from sqlite");
getListView().addHeaderView(tView);
setListAdapter(new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, results));
getListView().setTextFilterEnabled(true);
}
private void openAndQueryDatabase() {
try {
DatabaseHandler db = new DatabaseHandler(this.getApplicationContext());
newDB = db.getWritableDatabase();
Cursor c = newDB.rawQuery("SELECT * FROM " + tableName, null);
if (c != null ) {
if (c.moveToFirst()) {
do {
String pid = c.getString(c.getColumnIndex("id"));
String name = c.getString(c.getColumnIndex("name"));
String price = c.getString(c.getColumnIndex("price"));
String date = c.getString(c.getColumnIndex("created_at"));
Log.d("pid",pid);
results.add("Name: " + name + "\n Price: " + price + "\n Date posted: " + date);
}while (c.moveToNext());
}
}
} catch (SQLiteException se ) {
Log.e(getClass().getSimpleName(), "Could not create or Open the database");
} finally {
if (newDB != null)
newDB.execSQL("DELETE FROM " + tableName);
newDB.close();
}
}
}
Database handler:
public class DatabaseHandler extends SQLiteOpenHelper {
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 2;
// Database Name
private static final String DATABASE_NAME = "itemManager";
// table name
public static final String TABLE_ITEM = "item";
// Item Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_PRICE = "price";
private static final String KEY_CREATED_AT = "created_at";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_ITEM_TABLE = "CREATE TABLE " + TABLE_ITEM + "("
+ KEY_ID + " INTEGER PRIMARY KEY autoincrement,"
+ KEY_NAME + " TEXT, "
+ KEY_PRICE + " TEXT,"
+ KEY_CREATED_AT + " TEXT" + ")";
db.execSQL(CREATE_ITEM_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_ITEM);
// Create tables again
onCreate(db);
}
/**
* Storing item details in database
* */
public void addItem(Items item) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, item.getName()); // item name
values.put(KEY_PRICE, item.getPrice()); // item price
values.put(KEY_CREATED_AT, item.getDate()); // Created At
// Inserting Row
db.insert(TABLE_ITEM, null, values);
db.close(); // Closing database connection
}
/**
* Getting item data from database
* */
public List<Items> getAllItems(){
List<Items> itemList = new ArrayList<Items>();
String selectQuery = "SELECT * FROM " + TABLE_ITEM;
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
if (cursor.moveToFirst()) {
do {
Items item = new Items();
item.setID(Integer.parseInt(cursor.getString(0)));
item.setName(cursor.getString(1));
item.setPrice(cursor.getString(2));
item.setDate(cursor.getString(2));
// Adding item to list
itemList.add(item);
} while (cursor.moveToNext());
}
// return item list
return itemList;
}
/**
* return true if rows are there in table
* */
public int getRowCount() {
String countQuery = "SELECT * FROM " + TABLE_ITEM;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
// Updating item
public int updateItem(Items item) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, item.getName());
values.put(KEY_PRICE, item.getPrice());
values.put(KEY_CREATED_AT, item.getDate());
// updating row
return db.update(TABLE_ITEM, values, KEY_ID + " = ?",
new String[] { String.valueOf(item.getID()) });
}
// Deleting item
public void deleteItem(Items item) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_ITEM, KEY_ID + " = ?",
new String[] { String.valueOf(item.getID()) });
db.close();
}
}

Well, don't you delete all the records before closing the database?
} finally {
if (newDB != null)
newDB.execSQL("DELETE FROM " + tableName);
newDB.close();
}
That would explain that behaviour.

passing data from sqlite to a textview

I am trying to pass data from an sqlite table to a username textview in my home fragment class, I am having difficulties displaying the data in the textview.
Here is my DatabaseHelper class where all my table is created:
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 = "u168512214_barzd";
// Login table name
private static final String TABLE_LOGIN = "login";
// Login Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_EMAIL = "email";
private static final String KEY_UID = "uid";
private static final String KEY_CREATED_AT = "created_at";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LOGIN + "("
+ KEY_ID + " INTEGER PRIMARY KEY,"
+ KEY_NAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE,"
+ KEY_UID + " TEXT,"
+ KEY_CREATED_AT + " TEXT" + ")";
db.execSQL(CREATE_LOGIN_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_LOGIN);
// Create tables again
onCreate(db);
}
/**
* Storing user details in database
* */
public void addUser(String name, String email, String uid, String created_at) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, name); // Name
values.put(KEY_EMAIL, email); // Email
values.put(KEY_UID, uid); // Email
values.put(KEY_CREATED_AT, created_at); // Created At
// Inserting Row
db.insert(TABLE_LOGIN, null, values);
db.close(); // Closing database connection
}
/**
* Getting user data from database
* */
public HashMap<String, String> getUserDetails(){
HashMap<String,String> user = new HashMap<String,String>();
String selectQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
if(cursor.getCount() > 0){
Log.i("key_name","value is: " + cursor.getString(1));
Log.i("key_email","value is: " + cursor.getString(2));
Log.i("key_uid","value is: " + cursor.getString(3));
Log.i("key_created_at","value is: " + cursor.getString(4));
}
cursor.close();
db.close();
// return user
return user;
}
/**
* Getting user login status
* return true if rows are there in table
* */
public int getRowCount() {
String countQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
her is my fragmentHome class where I want to display the username in a textView:
DatabaseHandler db;
AlertDialogManager alert = new AlertDialogManager();
// Session Manager Class
ArrayList> nameList;
public HomeFragment(){}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
btnViewBars = (Button)rootView.findViewById(R.id.btnViewBars);
btnNewBar = (Button)rootView.findViewById(R.id.btnCreateBar);
// return rootView;
db= new DatabaseHandler(getActivity());
HashMap<String, String> user = db.getUserDetails();
for(int i=0; i<user.size();i++) {
username.settext(user.get(i).get("name"));
}

How I can start my Android SQLite Application without a Error

I want built a Android Application with a SQLite Database. I have two Java Classes. The First is the Contact Class ans the second the DatabaseHandle class for the operations how add, update etc...
I don't get a error but if I start my Application I become this message ...
Here is my Contact Class
package de.linde.sqlite;
public class Contact {
int _id;
String _name;
String _phone_number;
public Contact(){}
public Contact(int id,String name,String _phone_number){
this._id = id;
this._name = name;
this._phone_number = _phone_number;
}
public Contact(String name,String _phone_number){
this._name = name;
this._phone_number = _phone_number;
}
public int getID(){
return this._id;
}
public void setID(int id){
this._id = id;
}
public String getName(){
return this._name;
}
public void setName(String name){
this._name = name;
}
public String getPhoneNumber(){
return this._phone_number;
}
public void setPhoneNumber(String phone_number){
this._phone_number = phone_number;
}
}
Here is my DatabaseHandler Class
package de.linde.sqlite;
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 {
//Datenbank version
private static final int DATABASE_VERSION = 1;
//Datenbankname
private static final String DATABASE_NAME = "contactsManager";
//Tabellenname
private static final String TABLE_CONTACTS = "contacts";
//Tabellenspalten
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);
}
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);
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){
db.execSQL("DROP TABLE IF EXISTS" + TABLE_CONTACTS);
onCreate(db);
}
public 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 Number
// Inserting Row
db.insert(TABLE_CONTACTS, null, values);
db.close(); // Closing database connection
}
public 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;
}
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));
// Adding contact to list
contactList.add(contact);
} while (cursor.moveToNext());
}
// return contact list
return contactList;
}
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();
}
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()) });
}
public void deleteContact(Contact contact) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_CONTACTS, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
db.close();
}
}
Here is my MainActivity
package de.linde.sqlite;
import java.util.List;
import android.os.Bundle;
import android.util.Log;
import android.app.Activity;
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
DatabaseHandler db = new DatabaseHandler(this);
Log.d("Insert: ", "Inserting ..");
db.addContact(new Contact("Wladimir","024324324"));
db.addContact(new Contact("Max","0324324324"));
db.addContact(new Contact("Benny","0324324"));
db.addContact(new Contact("derSchwarze","051324324"));
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();
Log.d("Name: ", log);
}
}
}
My activity_main.xml
<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" >
</RelativeLayout>
What I make wrong :(

Add spaces between the values that you add to CREATE_CONTACTS_TABLE and the concatenated string, so you build a valid table creation string:
"CREATE TABLE " + TABLE_CONTACTS + " (" + KEY_ID + " INTEGER PRIMARY KEY, " + KEY_NAME + " TEXT, " + KEY_PH_NO + " TEXT)";
You'll need to uninstall the app from the phone/emulator and then run it again to make the database to be recreated again.
The same thing is valid for the String in the onUpgrade method:
"DROP TABLE IF EXISTS " + TABLE_CONTACTS

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How to read SQLite by cursor and display in textview - java

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