I've been playing with a sample application I found online. Just changing things to see how it works. Yesterday this was not an issue. Today is a different story. I seem to write the correct info to the db. I've checked through log outputs. When I return the information through a cursor I get "null". So, say I enter "Eggs","Bread", and "Candy". I get back "null","null", and "null".
It all starts with the listener for the add grocery button. Adds to the db and writes the list to an label.
Any help?
private void addEvent(String title) {
SQLiteDatabase db = eventsData.getWritableDatabase();
ContentValues values = new ContentValues();
Log.v(TAG, "Adding " + title);
values.put(EventsDataSQLHelper.TITLE, title);
db.insert(EventsDataSQLHelper.TABLE, null, values);
}
private Cursor getEvents() {
SQLiteDatabase db = eventsData.getReadableDatabase();
Cursor cursor = db.query(EventsDataSQLHelper.TABLE, null, null, null, null,
null, EventsDataSQLHelper.TITLE);
startManagingCursor(cursor);
return cursor;
}
private void showEvents(Cursor cursor) {
StringBuilder ret = new StringBuilder();
while (cursor.moveToNext()) {
String title = cursor.getString(1);
ret.append(title + "\n");
Log.v(TAG, "SHOWING RET VARIABLE" + ret);
}
t.setText(ret);
}
View.OnClickListener myhandler = new View.OnClickListener()
{
#Override
public void onClick(View GLview)
{
EditText eT = (EditText)findViewById(R.id.itemName1);
editTextStr = eT.getText().toString();
Log.v(TAG, editTextStr);
if(editTextStr != null)
{
addEvent(editTextStr.toString());
Cursor cursor = getEvents();
showEvents(cursor);
eT.setText(null);
}
}
};
Make sure cursor points to the first element of the result cursor.moveToFirst();
Then call cursor.moveToNext()
Related
I am creating app in which i register user and store user's information in database,so i have created database and storing value in databse but i don't know how to fetch data from database and show in textview?Using below query to fetch data but it has error.What is correct way?
public void insertEntry(String fname, String lname, String gen,String weight)
{
SQLiteDatabase db = dbHelper.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("firstname", fname);
values.put("lastname", lname);
values.put("gender", gen);
values.put("weight",weight);
}
public Cursor fetchData()
{
SQLiteDatabase mDB = dbHelper.getWritableDatabase();
return mDB.rawQuery("SELECT * FROM Register WHERE firstname=? lastname =?" , null);
}
Using this to set fetched value on textview in different activity
Cursor name = sqliteDataBase.fetchData();
tv_name.setText((CharSequence) name);
Try this,
try {
SQLiteDatabase mDB = dbHelper.getReadableDatabase();
String selectQuery = "SELECT * FROM Register WHERE firstname= "+first+" lastname =" + last + ";";
cursor = db.rawQuery(selectQuery, null);
if (cursor != null && cursor.getCount() > 0) {
if (cursor.moveToFirst()) {
String firstName = cursor.getString(cursor.getColumnIndex("firstname")));
}
}
} catch(Exception e) {
e.printSTackTrace();
} finally {
if (cursor != null) {
cursor.close();
}
}
public String fecthResults()
{
String name = null;
SQLiteDatabase sqLiteDatabase = getReadableDatabase();
Cursor cursor = sqLiteDatabase.query(TABLE_NAME, null, null, null, null, null, null);
if (cursor.moveToFirst()) {
do {
name = cursor.getString(cursor.getColumnIndex("firstname")
} while (cursor.moveToNext());
cursor.close();
}
sqLiteDatabase.close();
return name;
Get the name and then set it directly to a texView
A Cursor is an interface that provides random read-write access to the result set returned by the query. It contains multiple rows of data and this data can be easily processed by help of For loop.
Lets take an example to understand the process. Suppose, you need to access data from a column name "col_1" and show the data in TextView. The For loop for the process will be as follows.
for (cursor.moveToNext()) {
textView.setText(cursor.getString(cursor.getColumnIndex("col_1")));
}
Now, if we need only one value (from only one record or tuple) then, we can opt out the For loop and change the code as shown below.
if (cursor.moveToFirst()) {
textView.setText(cursor.getString(cursor.getColumnIndex("col_1")));
}
Always remember to close the cursor after using it.
To close the cursor, use the following line of code.
cursor.close();
For more information, please visit the following links:
https://developer.android.com/reference/android/database/Cursor.html
https://developer.android.com/training/basics/data-storage/databases.html#ReadDbRow
I am trying to query all the users data that belong to him uniquely. through FK_ID of the user in the notes table.
// Listing all notes
public Cursor listNotes() {
SQLiteDatabase db = help.getReadableDatabase();
Cursor c = db.query(help.NOTE_TABLE, new String[]{help.COLUMN_TITLE,help.COLUMN_BODY, help.COLUMN_DATE}, null, null, null, null, null);
if (c != null) {
c.moveToFirst();
}
return c;
}
// Count how many Notes user has
public int NoteCount() {
String countQuery = "SELECT * FROM " + help.NOTE_TABLE;
Cursor cursor = db.rawQuery(countQuery, null);
cursor.close();
// return count
return cursor.getCount();
}
// Updating single contact
public void editNote(long id, String title, String body) {
ContentValues edit = new ContentValues();
edit.put(help.COLUMN_TITLE, title);
edit.put(help.COLUMN_BODY, body);
open();
db.update(help.NOTE_TABLE, edit, help.NOTES_ID + "=" + id, null);
close();
}
// Deleting single note
public void deleteNote(long id) {
open();
db.delete(help.NOTE_TABLE, help.NOTES_ID + "=" + id, null);
close();
}
}
I have a tab that will then return all the users data uniquely to him. This tab is a fragment.the Method populateList() will be called onCreateView
public void populateList(){
Cursor cursor = control.listNotes();
getActivity().startManagingCursor(cursor);
//Mapping the fields cursor to text views
String[] fields = new String[]{help.COLUMN_TITLE,help.COLUMN_BODY, help.COLUMN_DATE};
int [] text = new int[] {R.id.item_title,R.id.item_body, R.id.item_date};
adapter = new SimpleCursorAdapter(getActivity(),R.layout.list_layout,cursor, fields, text,0);
//Calling list object instance
listView = (ListView) getView().findViewById(android.R.id.list);
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
}
This is a null pointer. Am i passing the data wrong
Cursor cursor = control.listNotes();
Your listNotes method should look like :
public Cursor listNotes(long userId) {
Cursor c = getActivity().getContentResolver().query(yourTodoTableURI, new String[]{help.COLUMN_TITLE,help.COLUMN_BODY, help.COLUMN_DATE}, help.COLUMN_USER_ID + " = ?", new String[]{String.valueOf(userId)} , null);
return c;
}
try this:
public List<String> getAllTask(int userID){
String query = "Select * from tablename where ID =" + userID;
cursor = db.query(); //do your code here
int id = cursor.getInt(cursor.getColumnIndex(tablename.ID));
List<String> task = new ArrayList<String>();
String query = "Select * from tableTask where ID =" + id";
cursor = db.query(); //
if (cursor != null) {
cursor.movetofirst();
// do your code here
do{
String task = cursor.get......
task.add(task);
}while(cursor.movetonext);
}
return task;
}
Hi i'm new to android programming and i have created a sample app which allows the user to get data from the database. however its not displaying the data, it doesn't have any error message its just not displaying it. database is confirmed that there is data. please check my code maybe i forgot something here. thanks
public void onClick(View arg){
name = txtNameS.getText().toString();
if(arg.getId()==R.id.btnfortune){
searchRecord(count);
lblmessageS1.setText(name); // this is just for me to check if it will be displayed and it is.
lblmessageS2.setText(message);
}
}
public void searchRecord(int count) throws SQLException {
Cursor rsCursor;
String [] rsFields = {"mesNum","Message"};
rsCursor = dbM.dbase.query("MessageFile", rsFields, "mesNum = " + count, null, null, null, null, null);
rsCursor.moveToFirst();
if (rsCursor.isAfterLast()==false){
message = rsCursor.getString(1);
}
rsCursor.close();
}
by the way count is initialized as 1. and there are 10 records in the database. and there are 2 columns in the database the mesNum and Message, what i want is to display only the message column.
// SQLiteDatabase sqldb
Cursor rsCursor= sqldb.rawQuery("your query", null);
if (rsCursor!= null) {
if (rsCursor.moveToFirst()) {
do {
// do here for get data message = rsCursor.getString(1);
}while (cursor.moveToNext());
}
cursor.close();
}
add only one column name in your array
String [] rsFields = {"Message"};
cursor = dbM.dbase.query(true,"MessageFile", rsFields, "yourcolumn= "+count, null, null, null, null, null);
while( cursor != null && cursor.moveToNext() )
{
cursor.getString(0);
}
cursor.close();
I'm new in Android. I'm trying to get a specific word from database (SQLite). But I couldn't make where clause work. Where am I making mistake?
My code is it:
private String[] sutunlar = {"ingilizce","turkce"};
public void kelimeUret() {
SQLiteDatabase db = kelimeler.getReadableDatabase();
Cursor kayit = db.query("kelimeler", sutunlar, "ingilizce='hello'", null, null, null, null);
String sonuc = kayit.getString(0);
Toast.makeText(getApplicationContext(), sonuc, Toast.LENGTH_SHORT).show();
}
I can not get a result...
Call kayit.moveToFirst() before calling kayit.getString(0).
You should do something like this
private String[] sutunlar = {"ingilizce","turkce"};
public void kelimeUret() {
SQLiteDatabase db = kelimeler.getReadableDatabase();
Cursor kayit = db.query("kelimeler", sutunlar, "ingilizce='hello'", null, null, null, null);
if (kayit.moveToFirst())
{
String sonuc = kayit.getString(0);
Toast.makeText(getApplicationContext(), sonuc, Toast.LENGTH_SHORT).show();
}
kayit.close();
}
I am getting cursor index out of bounds "index 0 requested: with size 0" error when I search my database for something. The item I am searching for in my database does not exist currently and i am aware of that but how do i handle a query where the item does not exist.
i send in a phone number
public String searchNumber(Context context,String number){
ContactDB db = new ContactDB(context);
db.open();
Cursor curs = db.getIdFromPhone(number);
String test = curs.getString(curs.getColumnIndex(db.PHONE_NUMBER)); //fails here
curs.close();
db.close();
return test;
}
query
public Cursor getIdFromPhone(String where){
Cursor cur = db.query(DATABASE_TABLE, new String [] {ID,PHONE_NUMBER}
, PHONE_NUMBER + "='" + where + "'",null,null,null,null);
if(cur != null)
cur.moveToFirst();
return cur;
}
test search
from = messages.getDisplayOriginatingAddress();
String dbNumber = searchNumber(arg0,from);
if(dbNumber.equals(from)){
//do stuff
}else{
//do other stuff
}
if number is not found it should do the else statement but it does not get that far
Cursor.moveToFirst() returns false if the Cursor is empty. The returned Cursor from the query() call will never be null but it might be empty. You are never checking if the cursor is empty.
public String searchNumber(Context context,String number){
ContactDB db = new ContactDB(context);
db.open();
Cursor curs = db.query(DATABASE_TABLE, new String [] {ID,PHONE_NUMBER}
, PHONE_NUMBER + "='" + number + "'",null,null,null,null);
String test = null;
if(curs.moveToFirst()) { //edit
test = curs.getString(curs.getColumnIndex(db.PHONE_NUMBER)); //fails here
}
curs.close();
db.close();
return test; // this will be null if the cursor is empty
}
And get rid of the getIdFromPhone() method.
While you retrive value you have to use cursor.moveToNext;
if (cursor.moveToFirst()){
do{
String data = cursor.getString(cursor.getColumnIndex("data"));
// do what ever you want here
}while(cursor.moveToNext());
}