So this is my first app and first database. I think I have finally created the DBAdapter correctly, and now I am trying to implement that into my main activity.
I have a save button listed under an onClick
public void onClick(View src) {
switch(src.getId()){
...other buttons here...
case R.id.buttonSave:
db.open();
long id;
id = db.insertFinalscore("20110612", "91", "18");
db.close();
break;
}
}
As I'm sure you can not see, I am trying to insert that data into the table. I have created an instance of DBAdapter inside my onClick:
public void onClick(View src) {
//***DATABASE INFO***//
DBAdapter db = new DBAdapter(this);
Is anyone able to tell me what I am missing? I am getting the following warning:
case R.id.buttonSave:
db.open();
long id; <--- The local variable id is never read
id = db.insertFinalscore("20110612", "91", "18");
db.close();
You are getting a warning, not an error. Basically the warning is saying that the variable id is never actually used. While you do set its value, you never read that value making the variable worthless. Your program will run just fine as is, but you might as well remove the variable id.
Your program should now look like this:
public void onClick(View src) {
switch(src.getId()){
...other buttons here...
case R.id.buttonSave:
db.open();
db.insertFinalscore("20110612", "91", "18");
db.close();
break;
}
}
Related
I have a table, c_question in which I stored some questions with this structure
autoincrement column _id,
question,
option1,
option2,
option3,
correct_answer
Now I want to retrieve the question in a TextView and the answers in a RadioGroup.
If the user selects the correct answer, then the question and options will change
in the same page.
Logcat: fatal exception at main ..... cursorIndexOutOfBoundException
The output shows the last data (question with answers) I entered in the db and if I click any answer, the app crashes.
String row="SELECT* FROM c_question";
final Cursor c=db.rawQuery(row, null);
c.moveToFirst();
if(c.moveToFirst())
{
do
{
tv1.setText(c.getString(1));
r0=(RadioButton)findViewById(R.id.radio0);
r0.setText(c.getString(2));
r1=(RadioButton)findViewById(R.id.radio1);
r1.setText(c.getString(3));
r2=(RadioButton)findViewById(R.id.radio2);
r2.setText(c.getString(4));
k.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
int idd=r.getCheckedRadioButtonId();
r0=(RadioButton)findViewById(idd);
String r=r0.getText().toString();
if(r.equals(c.getString(5)))
{
Toast.makeText(QuestionsOn.this, "correct!!!", 123).show();
;
} else
Toast.makeText(QuestionsOn.this, "Incorrect!!!", 123).show();
}
});
} while(c.moveToNext());
}
Output showing the last data(Question with options) I entered in DB
That's what you get when you update the save views in a loop; only the last "row" will get shown.
If you want to show a list of data from the database, you need some Adapter class in a ListView / ViewPager
and if I click any option, the app crashes...
According to the error, c.getString(5) doesn't exist, so seems like you didn't create your database with the correct number of columns.
I'm having a very strange issue on my Android app wherein when I am inserting a value to a DB table, the first entry is disappearing somehow. However, any subsequent entries are appearing fine.
To be a little more specific, part of my application allows users to create a simple log where they enter some text and when they save it, it shows up on a list of log entries. However, when I try to insert the very first entry to an empty table, that entry is not being displayed, nor does the database indicate there is any data when I query for a count.
Interestingly enough, when I look at the return of the database insert call (SQLiteDatabase.insert()) I see a valid row number returned. In fact, when I look at any log entry I've saved to the database, the row number is correctly incrementing. As per the docs, my understanding is that if a non-negative number is returned, the insert was successful.
Here is the code that takes the result of the EditText from my AlertDialog, creates a new log entry, and calls the insert method:
newPainLogEntryDialog.setPositiveButton("Save",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
//make new pain log entry
PainLog painLog = new PainLog();
painLog.setPainEntry(input.getText().toString());
painLog.setPainDateTime(Calendar.getInstance());
Database.init(PainLogTab.this.getActivity());
Database.createPainLog(painLog);
updatePainLogList();
//display success to user
Toast.makeText(PainLogTab.this.getActivity(),
"Log entry saved", Toast.LENGTH_SHORT).show();
}
});
The code for Database.createPainLog():
public static long createPainLog(PainLog painLog) {
ContentValues cv = new ContentValues();
cv.put(COLUMN_PAINLOG_ENTRY, painLog.getPainEntry());
cv.put(COLUMN_PAINLOG_DATETIME, painLog.getPainDateTimeString());
return getDatabase().insert(PAINLOG_TABLE, null, cv);
}
And the last call before the Toast message is updatePainLogList(), which gets all the DB entries:
public void updatePainLogList(){
Database.init(PainLogTab.this.getActivity());
final List<PainLog> painLogs = Database.getAllPainLogs();
painLogListAdapter.setPainLogs(painLogs);
Log.d(getClass().getSimpleName(), "number of painLogs found: " + painLogs.size());
getActivity().runOnUiThread(new Runnable() {
public void run() {
// reload content
PainLogTab.this.painLogListAdapter.notifyDataSetChanged();
if(painLogs.size() > 0){
getView().findViewById(android.R.id.empty).setVisibility(View.INVISIBLE);
}else{
getView().findViewById(android.R.id.empty).setVisibility(View.VISIBLE);
}
}
});
}
And for completion sake, the body of the getAll() and its accompanying method getCursor():
public static Cursor getPainLogCursor() {
String[] columns = new String[] {
COLUMN_PAINLOG_ID,
COLUMN_PAINLOG_ENTRY,
COLUMN_PAINLOG_DATETIME
};
return getDatabase().query(PAINLOG_TABLE, columns, null, null, null, null,
null);
}
public static List<PainLog> getAllPainLogs() {
List<PainLog> painLogs = new ArrayList<PainLog>();
Cursor cursor = Database.getPainLogCursor();
if (cursor.moveToFirst()) {
while (cursor.moveToNext()) {
PainLog painLog = new PainLog();
painLog.setId(cursor.getInt(IDX_PAINLOG_ID));
painLog.setPainEntry(cursor.getString(IDX_PAINLOG_ENTRY));
painLog.setPainDateTime(cursor.getString(IDX_PAINLOG_DATETIME));
painLogs.add(painLog);
}
}
cursor.close();
return painLogs;
}
Now with some code I can explain what debugging steps I have taken thus far. As mentioned above, when I look at the return of the DB insert, I get a positive, non-zero number. However, when I try to print the number of logs in the immediately following update method (no deletes or anything get called en route), it displays 0, and indeed if I follow the Cursor I find that it never enters the loop which adds logs to the list which is displayed, also indicating it is not picking up the entry.
I have tried to set the DB insert in a transaction so that I can manually commit, but this does not help either. What makes this more interesting to me is that I have similar functionality elsewhere in my app where I save user preferences and display them in a list, and this does not suffer from the same problem...I have compared against this code and couldn't find any differences that would cause it.
To sum it up, my question is two-fold: why is only my first insert on an empty table showing up as not there, while all following ones are fine?; why am I getting a valid return from the database insert and yet immediately following the insert when I query for that data it is missing?
Thanks in advance for any help you can provide :)
if (cursor.moveToFirst()) {
while (cursor.moveToNext()) {
This skips the first row in cursor. moveToFirst() moves to the first row and moveToNext() moves to the next one, skipping the first one.
You can replace this with just while (cursor.moveToNext()). When you get your cursor from a query, it is placed at index -1 first i.e. at the row before the first one.
if (cursor.moveToFirst()) {
while (cursor.moveToNext()) {
This would be the best solution for it....
I have a ADD TO CART Button to add the products to cart and in database.I would like to show the same button as ALREADY IN CART if the product is already in cart.I tried using if else,but it is not working.It does n't crash VM.But no effect on clicking.
My Code
add2cart.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
String nm=name.getText().toString();
String rate=price.getText().toString();
mydb=Product_Details.this.openOrCreateDatabase("addcart", MODE_PRIVATE, null);
Cursor cur=mydb.rawQuery("select * from add2cart where pnme='"+nm+"'",null);
while (cur.moveToNext())
{
String name=cur.getString(cur.getColumnIndex("pnme"));
if (nm.equals(name))
{
add2cart.setText("Already in Cart");
}
else {
mydb.execSQL("INSERT INTO add2cart (pnme,prate)VALUES('"+nm+"','"+prprice+"')");
Toast.makeText(getApplicationContext(),"add to cart",Toast.LENGTH_SHORT).show();
Intent in=new Intent(Product_Details.this,add2cart.class);
startActivity(in);
} }
}
});
Perhaps you should try to rename one of your "name" variables. You could use this.name to specify which one you are referring to but I don't see the need to do that. The problem in fact might be that when you do if(nm.equals(name)) you are referring to the global variable name and not the one you set in the previous line. Hope I could help
I have a class that contains:
#Override
public void onClick(View createView) {
switch (createView.getId()) {
case R.id.save_button:
Appointments add = new Appointments();
add.addAppointment(TITLE);
add.addAppointment(TIME);
break;
}
}
I want to be able to call the addAppointment method which is in another class:
public void addAppointment(String string) {
// Insert a new record into the Appointment data source.
// You would do something similar for delete and update.
SQLiteDatabase db = events.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(TITLE, string);
values.put(TIME, string);
db.insertOrThrow(TABLE_NAME, null, values);
}
I have tried this way, but when I click the onclick , the program crashes
#Override
public void onClick(View createView) {
switch (createView.getId()) {
case R.id.save_button:
Appointments add = new Appointments();
add.addAppointment(TITLE, TIME); //Send both together
break;
}
}
I want to be able to call the addAppointment method which is in another class:
public void addAppointment(String title, String time) { // Change method header to accept both Strings here
// Insert a new record into the Appointment data source.
// You would do something similar for delete and update.
SQLiteDatabase db = events.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("title", title); // second param is what you passed in for first param of method
values.put("time", time); // second param here is whatever you passed in for second param of method
db.insertOrThrow(TABLE_NAME, null, values);
}
I don't know what TITLE and TIME are because I don't see them declared or initialized anywhere but inside the vaules.put() should be (key, value) so you make the key something descriptive about the value and the value obviously just that. Normally all caps represent a constant so just something to think about to keep up with standards
write method with two parameters 1st.calling method one after other with one parameter won't give you both values.
add.addAppointment(TITLE,TIME);
when button is pressed i want to the text to change to the database collumn values, i know its wrong but here is the code:
private void MostraDados() {
// TODO Auto-generated method stub
final TextView text = (TextView) findViewById(R.id.tvUSUARIO);
Button mostrar = (Button) findViewById(R.id.bMostrar);
mostrar.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// TODO Auto-generated method stub
db = openOrCreateDatabase("dbtest.db", Context.MODE_PRIVATE, null);
String q = "SELECT * FROM dbtest.db WHERE usuarioorigem='";
text.setText(q);
//text.execSQL("DROP COLUMN IF EXISTS usuarioorigem");
}
});
}
Your code is missing some critical parts for example a DatabaseClass that manages the cursor and database.
private void MostraDados() {
final TextView text = (TextView) findViewById(R.id.tvUSUARIO);
Button mostrar = (Button) findViewById(R.id.bMostrar);
mostrar.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// our missing a database helper
MyDatabaseClass dbhelper = new MyDatabaseClass();
dbhelper.open();
Cursor result = dbhelper.doMyQuery();
String mystring = result.getString(0);
text.setText(mystring);
dbhelper.close();
}
});
....
public class WorkoutDbAdapter {
....
public Cursor doMyQuery()
{
return this.mDb.query( yourQuery );
}
}
This is the minimum you'd need and even with the above i'm missing a lot of the smaller detail. Search for some tutorials on creating and using Databases.
Essentially however you need to get the cursor back, set the position of the cursor, or cursor.moveNext() and then get the value that you can assign to the textField.
Your source code lacks a correct call to a database and access to the cursor. Hopefully you'll find some decent tutorials that will flesh the rest out for you.
The SQL is not written correctly. You must SELECT from a column. And you're passing the query string the the text view. You should first review how to query the database with the cursor, and how to retrieve what you want from the cursor.
So I would look into how to use the curosr, all of that's available in the Android docs, and you might want to try the API demos in the emulator I'm sure you can learn how to work with the cursor there as well. So look here, http://developer.android.com/reference/android/database/Cursor.html.
And here, Is Android Cursor.moveToNext() Documentation Correct?.
After getting the cursor, you could do something like this:
while(c.moveToNext(){
text.setText(c.getString(0))
}