data in the row is not deleted from table

data in the row is not deleted from table - java

when I click delete it doesn't delete or edit the row I created
so my MainActivity is
package com.frolicfreak.bhushan.memo;
import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import static com.frolicfreak.bhushan.memo.DatabaseHelper.Table_Name;
import static com.frolicfreak.bhushan.memo.DatabaseHelper.col1;
import static com.frolicfreak.bhushan.memo.DatabaseHelper.col2;
public class MainActivity extends AppCompatActivity implements
View.OnClickListener{
FloatingActionButton fab;
DatabaseHelper mydb;
ListView listView;
ArrayAdapter<String> mAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mydb =new DatabaseHelper(this);
fab= (FloatingActionButton)findViewById(R.id.fab);
fab.setOnClickListener(this);
ListView listView = (ListView)findViewById(R.id.list);
registerForContextMenu(listView);
}
#Override
public void onResume() {
super.onResume();
ArrayList<String> theList =new ArrayList<>();
Cursor data= mydb.getAllData();
listView = (ListView)findViewById(R.id.list);
listView.setAdapter(null);
if (data.getCount()==0){
Toast.makeText(MainActivity.this,"data not inserted",Toast.LENGTH_LONG).show();
}
else
{
while(data.moveToNext()){
theList.add(data.getString(1));
ListAdapter listAdapter=new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,theList);
listView.setAdapter(listAdapter);
}
}
}
#Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
if (v.getId()==R.id.list) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
}
}
#Override
public boolean onContextItemSelected(MenuItem item) {
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
switch(item.getItemId()) {
case R.id.edit:
// int count= mydb.updaterow(getString(col2),EditText.)
return true;
case R.id.delete:
int count=mydb.deleterow(getString(item.getItemId()));
onResume();
return true;
default:
return super.onContextItemSelected(item);
}
}
#Override
public void onClick(View v) {
Intent intent= new Intent(this,Main2Activity.class);
startActivity(intent);
}
}
My DataBasehelper class
package com.frolicfreak.bhushan.memo;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.widget.EditText;
import java.util.ArrayList;
/**
* Created by BHUSHAN on 24-08-2017.
*/
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String Database_Name = "Memo.db";
public static final String Table_Name = "Memo";
public static final String col1 = "ID";
public static final String col2 = "data";
//DatabaseHelper mydb;
public DatabaseHelper(Context context) {
super(context, Database_Name, null, 1);
//mydb=new DatabaseHelper(context);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + Table_Name + "(ID integer primary key autoincrement, data text)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("drop table if exists " + Table_Name);
onCreate(db);
}
public boolean insertData(String data, String Data) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(col2, Data);
long result = db.insert(Table_Name, null, contentValues);
if (result==-1)
return false;
else
return true;
}
public ArrayList<String> getList(){
ArrayList<String> taskList = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor= db.query(Table_Name,new String[]{col1},new String(col2),null,null,null,null);
while (cursor.moveToNext()){
int index= cursor.getColumnIndex(col1);
taskList.add(cursor.getString(index));
}
cursor.close();
db.close();
return taskList;
}
public Cursor getAllData() {
SQLiteDatabase db = this.getWritableDatabase();
Cursor res = db.rawQuery("SELECT * FROM " + Table_Name, null);
return res;
}
public int deleterow(String col1) {
String whereClause = "ID = ?";
String[] whereArgs = {String.valueOf(col1)};
SQLiteDatabase db = this.getWritableDatabase();
int count = db.delete(Table_Name, whereClause, whereArgs);
db.close();
return count;
}
/* public int updaterow(String oldname, String newdata){
SQLiteDatabase db= mydb.getWritableDatabase();
ContentValues cv=new ContentValues();
cv.put(DatabaseHelper.col2,newdata);
String[] whereargs={oldname};
int count = db.update(Table_Name,cv, DatabaseHelper.col2+"=?" , whereargs);
return count;
}*/
}
my Main2Activity class where I edit and insert data
package com.frolicfreak.bhushan.memo;
import android.support.design.widget.FloatingActionButton;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class Main2Activity extends AppCompatActivity {
DatabaseHelper db;
EditText Data;
FloatingActionButton add;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
db = new DatabaseHelper(this);
Data = (EditText)findViewById(R.id.edit);
add =(FloatingActionButton)findViewById(R.id.add);
AddData();
}
public void AddData(){
add.setOnClickListener(
new View.OnClickListener() {
#Override
public void onClick(View v) {
boolean isInserted =
db.insertData(Data.getText().toString(),
Data.getText().toString() );
if (isInserted==true)
Toast.makeText(Main2Activity.this,"data
inserted",Toast.LENGTH_LONG).show();
else
Toast.makeText(Main2Activity.this,"data not
inserted",Toast.LENGTH_LONG).show();
}
}
);
}
}
please help me I'm new to programming so I'm trying to learn here
thankyou in advance
and I actually need help with editing and saving the data too I wrote the code but I saved it in the comments

Your delete function is working fine according to the code. Check the return is greater than 0 or not.
But you won't be able to see the changes in the ListView because you have to populate the list again.
Set an CursorAdapter since you're using a database to link to the listview and use CursorAdapter.notifyDataSetChanged()
Or create a method that will recreate the listview when a delete occurs.
ArrayList<String> COUNTRIES = new ArrayList<>();
public void refreshView() {
MyDatabase database = new MyDatabase(ViewList.this);
Cursor cursor = database.fetchAllData();
COUNTRIES.clear();
while (cursor.moveToNext()) {
String temp = cursor.getString(cursor.getColumnIndex(database.COL1));
COUNTRIES.add(temp);
}
arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, COUNTRIES);
ListView listView = (ListView) findViewById(R.id.list);
listView.setAdapter(arrayAdapter);
}

When deleting, you are calling this
int count=mydb.deleterow(getString(item.getItemId()));
onResume();
You are not passing the id of selected item, but you are passing menu item's string fetched by getString(...) method, which is weird. There are so much unused code in your class.
I advice you to work on BaseAdapter and ListView.

It's not a good programming pattern to call onResume() method. You should extract it to different method and call it in onResume().
Anyway, in this case notifyDataSetChanged() is a solution what you are looking for.

Related

Android Sqlite can't get records from Listview

I am writing a program that saves to DB and then get infos from the DB using SQLiteOpenHelper.
Problem is I insert text from the edit text but I got nothing to show.
is the problem from the listview? cuz I extend from ArrayAdapter class not from enter code hereCursor adapter? or there is something wrong with my code. Please take a look at my code this is my main Acitvity
package com.perfectapps.fasaven.dbnews;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
import DBHelper.DBContract;
import DBHelper.DBModel;
import newsAdapter.NewsMainMenuAdapter;
public class MainActivity extends AppCompatActivity {
Button submitNews;
ListView newsListView;
ArrayList<DBModel> dbmodel = new ArrayList<DBModel>();
EditText titleEditText;
TextView tvTitle;
TextView tvInfo;
EditText infoEditText;
DBContract dbContract;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvTitle =(TextView)findViewById(R.id.tvTitle);
tvInfo =(TextView)findViewById(R.id.tvInfo);
submitNews = (Button)findViewById(R.id.submit_news);
newsListView = (ListView)findViewById(R.id.lvNews);
titleEditText = (EditText)findViewById(R.id.etNews);
infoEditText = (EditText)findViewById(R.id.etNewsInfo);
dbContract = new DBContract(this,null,null,1);
NewsMainMenuAdapter customeAdapter = new NewsMainMenuAdapter(getApplicationContext(), R.layout.row_news_element,dbmodel);
newsListView.setAdapter(customeAdapter);
// printDataBase();
submitNews.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
DBModel dbModel = new DBModel();
dbModel.setNewsInfos(infoEditText.getText().toString());
dbModel.setNewsTitle(titleEditText.getText().toString());
dbContract.addNews(dbModel);
Toast.makeText(getApplicationContext(),"saved to DB", Toast.LENGTH_LONG ).show();
titleEditText.setText("");
infoEditText.setText("");
// printDataBase();
}
});
}
public void printDataBase(){
DBModel dbModel = new DBModel();
String dbToStringTitle = dbContract.readNewsTitle();
tvTitle.setText(dbToStringTitle);
titleEditText.setText("");
String dbToStringInfo =dbContract.readNewsInfo();
tvInfo.setText(dbToStringInfo);
infoEditText.setText("");
}
}
This is my custom Adapter
package newsAdapter;
import android.support.annotation.LayoutRes;
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import DBHelper.*;
import com.perfectapps.fasaven.dbnews.*;
import java.util.ArrayList;
/**
* Created by Salem on 22/12/2017.
*/
public class NewsMainMenuAdapter extends ArrayAdapter{
Context context;
ArrayList<DBModel> newsData;
int resource;
public NewsMainMenuAdapter(#NonNull Context context, #LayoutRes int resource, #NonNull ArrayList<DBModel> newsData) {
super(context, resource, newsData);
this.context =context;
this.newsData = newsData;
this.resource = resource;
}
#NonNull
#Override
public View getView(int position, #Nullable View convertView, #NonNull ViewGroup parent) {
LayoutInflater layoutInflater = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
convertView = layoutInflater.inflate(R.layout.row_news_element,null);
ViewHolder viewHolder = new ViewHolder();
viewHolder.tvInfo = (TextView)convertView.findViewById(R.id.tvInfo);
viewHolder.tvTitle = (TextView)convertView.findViewById(R.id.tvTitle);
viewHolder.tvTitle.setText(newsData.get(position).getNewsTitle());
viewHolder.tvInfo.setText(newsData.get(position).getNewsInfos());
//return super.getView(position, convertView, parent);
return convertView;
}
//#Nullable
// #Override
// public DBModel getItem(int position) {
// return super.getItem(position);
//}
class ViewHolder{
TextView tvTitle;
TextView tvInfo;
}
}
Here is my DB helper
package DBHelper;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* Created by Salem on 22/12/2017.
*/
public class DBContract extends SQLiteOpenHelper {
private static final int DB_VERSION = 1;
private static final String DB_NAME = "newsDB.db";
public static final String TABLE_NAME = "news";
public static final String COLUMN_ID = "_ID";
public static final String COLUMN_NEWS_TITLE = "newstitle";
public static final String COLUMN_NEWS_IMAGE = "newsimage";
public static final String COLUMN_NEWS_INFO= "newsinfo";
public DBContract(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, DB_NAME, factory, DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE "+ TABLE_NAME + " ("
+COLUMN_ID+ " INTEGER PRIMARY KEY AUTOINCREMENT , "
+COLUMN_NEWS_TITLE+ " TEXT ,"
+COLUMN_NEWS_INFO+ " TEXT );";
db.execSQL(query);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME );
onCreate(db);
}
public void addNews(DBModel dbModel){
ContentValues contentValues = new ContentValues();
contentValues.put(COLUMN_NEWS_TITLE, dbModel.getNewsTitle());
contentValues.put(COLUMN_NEWS_INFO, dbModel.getNewsInfos());
SQLiteDatabase sqLiteDatabase = getWritableDatabase();
sqLiteDatabase.insert(TABLE_NAME, null, contentValues);
sqLiteDatabase.close();
}
public String readNewsTitle(){
String readNews = "";
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT "+COLUMN_NEWS_TITLE+" FROM "+TABLE_NAME +" where 1";
Cursor cursor = sqLiteDatabase.rawQuery(query, null);
cursor.moveToFirst();
while(!cursor.isAfterLast()){
if(cursor.getString(cursor.getColumnIndex(COLUMN_NEWS_TITLE))!=null);
{
readNews += cursor.getString(cursor.getColumnIndex(COLUMN_NEWS_TITLE));
readNews +="\n";
}
cursor.moveToNext();
}
sqLiteDatabase.close();
return readNews;
}
public String readNewsInfo(){
String readNewsInfo="";
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
String query = "SELECT "+COLUMN_NEWS_INFO+" FROM "+TABLE_NAME ;
Cursor cursor = sqLiteDatabase.rawQuery(query, null);
cursor.moveToFirst();
while(!cursor.isAfterLast()){
if(cursor.getString(cursor.getColumnIndex(COLUMN_NEWS_INFO))!=null);
{
readNewsInfo += cursor.getString(cursor.getColumnIndex(COLUMN_NEWS_INFO));
readNewsInfo +="\n";
}
cursor.moveToNext();
}
sqLiteDatabase.close();
return readNewsInfo;
}
}
There is one 4th class that has setters and getters named DBModel
and got XML for main activity which has listview.. but it when I input from edit text it doesn't show there

get value from database column by listview item click

i'm trying to get value from 2nd column in the database and put it into textview by clicking listview item.
DBConnection class
package com.prodev;
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;
/**
* Created by Dev_Mohamed_Sayed on 7/21/2017.
*/
public class DBConnection extends SQLiteOpenHelper {
public static final String DbName="azkar.db";
public static final int Version=1;
public DBConnection(Context context){
super(context,DbName,null,Version);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE IF NOT EXISTS azkar_main ( ID INTEGER, Name TEXT, Number INTEGER, PRIMARY KEY(ID) )");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS azkar_main");
onCreate(db);
}
public void InsertRowAdmin(String Name,Integer Number){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put("Name", Name);
contentValues.put("Number", Number);
db.insert("azkar_main", null, contentValues);
}
public ArrayList getAllRecord2(){
ArrayList array_list2 = new ArrayList();
SQLiteDatabase db = this.getReadableDatabase();
Cursor res = db.rawQuery("select * from azkar_main", null);
res.moveToFirst();
while (res.isAfterLast() == false){
array_list2.add(res.getString(res.getColumnIndex("ID"))+ " - " + res.getString(res.getColumnIndex("Name"))+ " .. " + res.getString(res.getColumnIndex("Number")));
res.moveToNext();
}
return array_list2;
}
public void delete(Integer ID){
SQLiteDatabase db = this.getWritableDatabase();
db.execSQL("delete from azkar_main where ID="+ Integer.toString(ID));
}
}
and here is my Acivity where we should work in.
package com.prodev;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.R.layout;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.TextView;
import java.util.ArrayList;
public class ListActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setLogo(R.mipmap.ic_launcher);
getSupportActionBar().setDisplayUseLogoEnabled(true);
setContentView(R.layout.activity_list);
DBConnection db = new DBConnection(this);
ListView ls =(ListView)findViewById(R.id.ls);
ArrayList<String> arrlist = db.getAllRecord2();
ls.setAdapter(new ArrayAdapter<>(this, layout.simple_list_item_1, arrlist));
ListView lv = (ListView) findViewById(R.id.ls);
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i = new Intent(ListActivity.this, MainActivity.class);
startActivity(i);
ListView lv = (ListView) findViewById(R.id.ls);
TextView tv = (TextView) findViewById(R.id.textView);
// The Missing Part
}
});
}
public void btn_save(View view){
EditText editText =(EditText)findViewById(R.id.editText);
ListView ls =(ListView)findViewById(R.id.ls);
DBConnection db = new DBConnection(this);
db.InsertRowAdmin(editText.getText().toString(), 0);
ArrayList<String> arrlist = db.getAllRecord2();
ls.setAdapter(new ArrayAdapter<>(this, layout.simple_list_item_1, arrlist));
editText.setText("");
}
public void btn_delete(View view){
EditText txt = (EditText)findViewById(R.id.del);
ListView ls = (ListView)findViewById(R.id.ls);
DBConnection db = new DBConnection(this);
db.delete(Integer.parseInt(txt.getText().toString()));
ArrayList<String> arrlist=db.getAllRecord2();
ls.setAdapter(new ArrayAdapter<>(this, layout.simple_list_item_1, arrlist));
txt.setText("");
}
}
MainActivity
package com.prodev;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;
import com.google.firebase.analytics.FirebaseAnalytics;
import com.google.firebase.crash.FirebaseCrash;
public class MainActivity extends AppCompatActivity {
private FirebaseAnalytics mFirebaseAnalytics;
private static final String TAG = "MainActivity";
private AdView mAdView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mFirebaseAnalytics = FirebaseAnalytics.getInstance(this);
FirebaseCrash.log("Activity created");
getSupportActionBar().setDisplayShowTitleEnabled(false);
getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setLogo(R.mipmap.ic_launcher);
getSupportActionBar().setDisplayUseLogoEnabled(true);
setContentView(R.layout.activity_main);
mAdView = (AdView) findViewById(R.id.adView);
AdRequest adRequest = new AdRequest.Builder().build();
mAdView.loadAd(adRequest);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.mainmenu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
// action with ID action_refresh was selected
case R.id.action_azkar:
Intent i = new Intent(MainActivity.this, ListActivity.class);
startActivity(i);
break;
case R.id.action_settings:
break;
default:
break;
}
return true;
}
}
Also i want to save number from variable will be declared later into database col Number..
i don't know how but i'll worry about that later..

On you list item click event,
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i = new Intent(ListActivity.this, MainActivity.class);
i.putExtra("keyText","value to be passed!");
startActivity(i);
}
and in you main activity,
Intent i = getIntent();
String text = i.getStringExtra("keyText");
TextView tv = (TextView) findViewById(R.id.textView);
tv.setText(text);

How to turn this activity into a fragment?

I am working on a sql listview , however I want to display the listview which is in an activity class (CountryListActivity.java) as a fragment in a tablayout . dbManager=newDBManager(this) gives an error when I change it to getActivity , how do I fix this?
package com.trinitytabnavigationdrawer;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.support.v4.widget.SimpleCursorAdapter;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.TextView;
public class CountryListActivity extends ActionBarActivity {
private DBManager dbManager;
private ListView listView;
private SimpleCursorAdapter adapter;
final String[] from = new String[] {
DatabaseHelper._ID,
DatabaseHelper.SUBJECT, DatabaseHelper.DESC
};
final int[] to = new int[] {
R.id.id, R.id.title, R.id.desc
};
#
Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_emp_list);
dbManager = new DBManager(this);
dbManager.open();
Cursor cursor = dbManager.fetch();
listView = (ListView) findViewById(R.id.list_view);
listView.setEmptyView(findViewById(R.id.empty));
adapter = new SimpleCursorAdapter(this, R.layout.activity_view_record, cursor, from, to, 0);
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
// OnCLickListiner For List Items
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {#
Override
public void onItemClick(AdapterView <? > parent, View view, int position, long viewId) {
TextView idTextView = (TextView) view.findViewById(R.id.id);
TextView titleTextView = (TextView) view.findViewById(R.id.title);
TextView descTextView = (TextView) view.findViewById(R.id.desc);
String id = idTextView.getText().toString();
String title = titleTextView.getText().toString();
String desc = descTextView.getText().toString();
Intent modify_intent = new Intent(getApplicationContext(), ModifyCountryActivity.class);
modify_intent.putExtra("title", title);
modify_intent.putExtra("desc", desc);
modify_intent.putExtra("id", id);
startActivity(modify_intent);
}
});
}
#
Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#
Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.add_record) {
Intent add_mem = new Intent(this, AddCountryActivity.class);
startActivity(add_mem);
}
return super.onOptionsItemSelected(item);
}
}
And the database manager class is as follows :
package com.trinitytabnavigationdrawer;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
public class DBManager {
private DatabaseHelper dbHelper;
private Context context;
private SQLiteDatabase database;
public DBManager(Context c) {
context = c;
}
public DBManager open() throws SQLException {
dbHelper = new DatabaseHelper(context);
database = dbHelper.getWritableDatabase();
return this;
}
public void close() {
dbHelper.close();
}
public void insert(String name, String desc) {
ContentValues contentValue = new ContentValues();
contentValue.put(DatabaseHelper.SUBJECT, name);
contentValue.put(DatabaseHelper.DESC, desc);
database.insert(DatabaseHelper.TABLE_NAME, null, contentValue);
}
public Cursor fetch() {
String[] columns = new String[] {
DatabaseHelper._ID, DatabaseHelper.SUBJECT, DatabaseHelper.DESC
};
Cursor cursor = database.query(DatabaseHelper.TABLE_NAME, columns, null, null, null, null, null);
if (cursor != null) {
cursor.moveToFirst();
}
return cursor;
}
public int update(long _id, String name, String desc) {
ContentValues contentValues = new ContentValues();
contentValues.put(DatabaseHelper.SUBJECT, name);
contentValues.put(DatabaseHelper.DESC, desc);
int i = database.update(DatabaseHelper.TABLE_NAME, contentValues, DatabaseHelper._ID + " = " + _id, null);
return i;
}
public void delete(long _id) {
database.delete(DatabaseHelper.TABLE_NAME, DatabaseHelper._ID + "=" + _id, null);
}
}
Please I have no clue what else to do ! Been trying for a week now , sorry I'm not good at this , just following some tutorials ! :(

Initialize the dbManager and other objects which require context inside onAttach (Context context) rather than onCreateView() method of Fragment.

Retrieve data into EditText from SQL Lite Database

I am currently working on a small application which allows a persons details to be stored in a database and then retrieved into an EditText field. Currently i am able to store a persons name into the database. But i am having trouble retrieving this data.
Any help anyone can give would be greatly appreciated!
Thanks!
DatabaseHelper.java:
package my.example.com.mymedicare;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
public class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context) {
super(context, "user.db", null, 4);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE Users (ID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL , FullName VARCHAR, Email VARCHAR, Number INTEGER, Age INTEGER, Nurse VARCHAR)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS Users");
// Create tables again
onCreate(db);
}
}
SQLHelper.java:
package my.example.com.mymedicare;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import java.io.File;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
public class SQLHelper {
Context mContext;
DatabaseHelper dbHelper;
public SQLHelper(Context mContext) {
dbHelper = new DatabaseHelper(mContext);
this.mContext = mContext;
}
public boolean insert(String FullName, int i){
SQLiteDatabase db = dbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("FullName", FullName);
db.close();
return true;
}
}
Register.java:
package my.example.com.mymedicare;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
public class Register extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
};
public void btnCreate(View view) {
SQLHelper sqlHelper = new SQLHelper(this);
EditText addName = (EditText) findViewById(R.id.nameText);
sqlHelper.insert(addName.getText().toString(), 0);
Toast.makeText(this, "Your Account Details Have Been Saved", Toast.LENGTH_SHORT).show();
startActivity(new Intent(Register.this, MainMenu.class));
}}
Modify.java:
package my.example.com.mymedicare;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.EditText;
public class Modify extends AppCompatActivity {
static SQLiteDatabase db;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_modify);
EditText getName=(EditText)findViewById(R.id.nameText);
}
}

Follow this step.
put this method in SQLHelper.java file.
public ArrayList<String> fetch_Edittext() {
ArrayList<String> arr_ = new ArrayList<String>();
String selectQuery = "Select * FROM " + TABLE_SCANITEMS + " ORDER BY id";
SQLiteDatabase db = this.getWritableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
if (cursor.moveToFirst()) {
do {
arr_.add(cursor.getString(0));
} while (cursor.moveToNext());
}
db.close();
return arr_;
}
put this class in your modify java class
private class GetEdittext extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// dialog start
Log.e("Currency", "3");
}
#Override
protected Void doInBackground(Void... arg0) {
ArrayList<String> arr_ = new ArrayList<String>();
arr_ = db.fetch_Edittext();
return null;
}
#Override
protected void onPostExecute(Void resul) {
super.onPostExecute(resul);
// dialog dismiss
//hear set your edit text
}
}
then call this class at on create method like.
new GetEdittext().execute();

search and retrieve the result in list-android

I am trying to search and retrieve the result in list view from sqlite database. When I try to search, the app closed.
Logcat
04-20 11:50:56.550 2297-2297/com.example.asus.myapplication3.app
E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.asus.myapplication3.app, PID: 2297
java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.sqlite.SQLiteDatabase
com.example.asus.myapplication3.app.dbtry$DatabaseHelper.getReadableDatabase()'
on a null object reference
at com.example.asus.myapplication3.app.searchActivity$1.onClick(searchActivity.java:62)
at android.view.View.performClick(View.java:4756)
at android.view.View$PerformClick.run(View.java:19749)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)
Code
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import java.net.ContentHandler;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
public class ListAdapter extends ArrayAdapter {
List list= new ArrayList();
static class layoutHandler
{
TextView nameText;
}
public ListAdapter(Context context, int resource)
{
super(context, resource);
}
#Override
public void add (Object object){
super.add(object);
list.add(object);
}
#Override
public int getCount() {
return list.size();
}
#Override
public Object getItem(int position)
{
return list.get(position);
}
#Override
// retern each row of data
public View getView(int position, View convertView, ViewGroup parent) {
View row = convertView;
layoutHandler layouthandler;
if (row==null){
LayoutInflater layoutInflater =(LayoutInflater)this.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row=layoutInflater.inflate(R.layout.result,parent,false);
// row=layoutInflater.inflate(R.layout.listrow,parent,false);
layouthandler=new layoutHandler();
layouthandler.nameText=(TextView)row.findViewById(R.id.nameText);
row.setTag(layouthandler);
}
else
{
layouthandler =(layoutHandler) row.getTag();
}
// return each abject from the list
dataProvider provider=(dataProvider)this.getItem(position);
//assaien each row of data
layouthandler.nameText.setText(provider.getName());
return row;
}
}
public class dataProvider {
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public dataProvider(String name) {
this.name = name;
}
}
import android.app.Activity;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.app.Activity;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CursorAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
public class searchActivity extends Activity {
EditText rname;
TextView result;
Button search;
dbtry db;
ListView data;
ListAdapter listAdapter;
String search_name;
SQLiteDatabase sqLiteDatabase;
dbtry.DatabaseHelper dbhlper;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.search);
search = (Button) findViewById(R.id.search);
rname = (EditText) findViewById(R.id.rname);
data = (ListView) findViewById(R.id.data);
search.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// setContentView(R.layout.result);
search_name = rname.getText().toString();
//db = new dbtry(getBaseContext());
sqLiteDatabase= dbhlper.getReadableDatabase();
Log.e("the app search ","dbhlper");
db.open();
Cursor d = db.returndata(search_name, sqLiteDatabase);
Log.e("the app search ","yah!");
listAdapter = new ListAdapter(getApplicationContext(), R.layout.listrow);
data.setAdapter(listAdapter);
data.setVisibility(View.GONE);
if (d.moveToFirst()) {
do {
String result_search;
result_search = d.getString(0);
//adding data to adapter
dataProvider provider = new dataProvider(result_search);
listAdapter.add(provider);
Log.e("the app search ","good");
} while (d.moveToNext());
}
// startActivity( new Intent(searchActivity.this, resultActivity.class));
}
}); }}
package com.example.asus.myapplication3.app;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
import java.sql.SQLException;
public class dbtry {
public static int _id;
public static final String ecapp_col_name = "name";
public static final String ecapp_col_discrption = "discrption";
public static final String ecapp_col_ingredant = "ingredant";
// public static final String ecapp_image = "image";
public static final String ecapp_col_Optional_ingredant = "Optional_ingredant";
public static final String TABLE_NAME1 = "recipe";
public static final String TABLE_NAME2 = "ingredant";
public static final String DATABASE_NAME="ecapp";
public static final int DATABASE_VERSION=1;
public static final String DATABASE_create1 = "create"+ TABLE_NAME1+ "("+_id +"int not null auto_increment,"+ecapp_col_name+" text UNIQUE,"+ecapp_col_discrption +"text+ );";
public static final String DATABASE_create2 = "create "+TABLE_NAME2+ "("+ ecapp_col_ingredant+"text ,"+ecapp_col_Optional_ingredant+"text ,"+_id+ "number );";
DatabaseHelper dbh;
Context con;
SQLiteDatabase db2;
public dbtry(Context con)
{
this.con = con;
dbh = new DatabaseHelper(con);
}
public static class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper (Context con)
{
super(con,DATABASE_NAME,null,DATABASE_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(DATABASE_create1);
db.execSQL(DATABASE_create2);
Log.d("db created ", "table2");
}
catch (Exception e) {
e.printStackTrace();
Log.e("db not created ", "bad");
}
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS ecapp");
onCreate(db);
}
}
public dbtry open()
{
db2= dbh.getWritableDatabase();
return this;
}
public void close()
{
dbh.close();
}
public void insertData(String name, String ingredant, String discrption) {
ContentValues content = new ContentValues();
content.put(ecapp_col_name, name);
Log.e("db created ", "good");
content.put(ecapp_col_ingredant, ingredant);
Log.e("db created ", "good");
content.put(ecapp_col_discrption, discrption);
Log.e("db created ", "good");
db2.insert("ecapp", null, content);
Log.e("db created ", "good");
}
//retrieve
public Cursor returndata(String sname, SQLiteDatabase sqldb)
{
sqldb = dbh.getReadableDatabase();
String selection, selectionArg;
Cursor query;
String[] projection = {ecapp_col_name};
String[] where = {ecapp_col_name};
query = sqldb.query(TABLE_NAME1, projection,sname,null, null, null, null);
// query = sqldb.query( "select"+ecapp_col_name+ "form" +TABLE_NAME1+"where "+ecapp_col_name+"="+sname+;)
Log.e( "get all data:", "query");
return query;
}
}

In your project's searchActivity, inside search.setOnClickListener before initializing sqLiteDatabase= dbhlper.getReadableDatabase(); add these line db = new dbtry(searchActivity.this); to avoid NullPointerException.
Also comment this line sqLiteDatabase= dbhlper.getReadableDatabase(); since you are already using SQLiteDatabase db2; inside open() method here as
public dbtry open()
{
db2= dbh.getWritableDatabase();
return this;
}
So no need for dbHelper & sqliteDatabase inside searchActivity class, just call db.open(). In case you want to read from database create another method read() similar to your open() method inside dbtry class
public dbtry read()
{
db2= dbh.getReadableDatabase();
return this;
}
Usage: db.read(); call this inside your searchActivity only after intializing db.
Happy coding..!!

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

data in the row is not deleted from table - java

It's not a good programming pattern to call onResume() method. You should extract it to different method and call it in onResume(). Anyway, in this case notifyDataSetChanged() is a solution what you are looking for.

Related

Android Sqlite can't get records from Listview

get value from database column by listview item click

How to turn this activity into a fragment?

Retrieve data into EditText from SQL Lite Database

search and retrieve the result in list-android

Categories

Resources