Develop Reference

moveToFirst does not work

I am using moveToFirst and it works very well. But this sql query doesnt work. I don't know why. I didn't receive any error.
My query
String sqlKomut = "SELECT SHareket.*,CHareket.[Meblag],Cari.AnlikBakiye FROM CHareket , SHareket,Cari WHERE CHareket.[CariID]=SHareket.[CariID]=Cari.[CariID]= '"+cari.getCariID()+"' AND SHareket.[Seri]='"+hareket.getSeri()+"' AND SHareket.[Sira]='"+hareket.getSira()+"'AND SHareket.[Tip]='"+hareket.getTip()+"' AND SHareket.[Cins]='"+hareket.getCins()+"' ORDER BY SHareket.[Satir]";
and I get my cursor getValue here:
Cursor cursor = db.rawQuery(sqlKomut, null);
if(cursor !=null){
if(cursor.moveToFirst()){
do {
eleman.setStrEleman(cursor.getString(cursor.getColumnIndex("Seri")));
eleman.setIntEleman1(cursor.getInt(cursor.getColumnIndex("Sira")));
eleman.setIntEleman2(cursor.getInt(cursor.getColumnIndex("CariID")));
eleman.setIntEleman10(cursor.getInt(cursor.getColumnIndex("Cins")));
eleman.setIntEleman11(cursor.getInt(cursor.getColumnIndex("Tip")));
eleman.setIntEleman11(cursor.getInt(cursor.getColumnIndex("Satir")));
eklenenfaturalar.add(eleman);
} while (cursor.moveToNext());
}
}

WHERE CHareket.[CariID]=SHareket.[CariID]=Cari.[CariID]= '...'
You cannot do multiple comparisons in a single expression like that.
(The comparison returns a boolean value, 0 or 1; any more comparisons will then use this boolean instead of an ID value, e.g., you end up with something like 1=Cari.CariID.)
To use multiple comparisons, connect them with AND (as you already did with the other ones):
WHERE CHareket.[CariID]=SHareket.[CariID]
AND SHareket.[CariID]=Cari.[CariID]
AND Cari.[CariID]='...'
...

Reading a value from a database

I have a database in my app with several columns of which 3 are: _id name selected.
Now, I want to read a single selected value from a row with the name being a string I get from some code. What would be the best way to do this?
Thanks
P.S. I am getting that value to check if it's 0 or 1 (only two possible values), so I want to ask how to make a kind of an if statement in the return field? I have seen some people do it with something resembling this: return true ? ... false
EDIT:
Okay, this is my code atm, haven't checked it yet since I need to do some other things to get it all up, but I think there may be a better way to do this.
public boolean isBandSelected(String name) {
// TODO Auto-generated method stub
Cursor cursor = mDb.query("bands", new String[] { "selected" }, "name="
+ name, null, null, null, null);
int index = cursor.getColumnIndex("selected");
String selected = cursor.getString(index);
return selected == "1";
}

You can use regular expression to match rows whose name field being string. Many databases can support regular expression.
The ternary operator(? :) can be used to make return statement like this.
return value == 0 ? false : true
But it depends on what kind of data type you what to return. Code above returns boolean data type.
The last line of your code above will always return false. This is because the == operator compares the reference of the two objects. you can use:
return "1".equals(selected);

How to get specific rows from ContentProvider?

I am a little new to using content providers. I was wondering how I would get specific rows from a content provider?
For example how would I get the first row of my provider?
This is what I tried but It isnt working:
final Cursor cursorConversations = getActivity().getContentResolver()
.query(CONTENT_URI, null, null, null, null);
Toast.makeText(
getActivity(),
cursorConversations.getString(cursorConversations
.getColumnIndex(Columns.TITLE)),
Toast.LENGTH_LONG).show();

you simply use cursor move methods ex:
cursorConversations.moveToFirst();
cursorConversations.moveToPosition(0);
cursorConversations.moveToNext(); // <-- if at beginning position
just to make this answer a little more meaty, a popular technique used to loop through the rows of the cursor 1 by 1 from the beginning is:
while (cursorConversations.moveToNext()) {
// do something
}
Because the moveToNext() method (as well as other move methods) return a boolean, the loop will exit when the last row has been reached and can no longer moved to the next. effective and easy on the eyes too. One more tip: the cursor starts at the -1 index, before the first position of a zero-based query index results.

use something like this:---
if(cursorConversations.moveToFirst()){
int size=cursorConversations.getCount();
for(int i=0;i<size;i++){
cursorConversations.getString(cursorConversations
.getColumnIndex(Columns.TITLE));
cursorConversations.moveToNext();
}
}
cursorConversations.close();
Or
while(cursorConversations.moveTonext())
{
cursorConversations.getString(cursorConversations
.getColumnIndex(Columns.TITLE));
}

Check if SQL integer field is empty

I try to get an Item out of my SQL db in android, everything goes well, the only thing I am struggling with is to get the INTEGER value is there is nothing filled in in the DB (null?)
So I first initialize it, then get the Integer value out of the DB and then assign it to an instance of my class. I was once told that if it will get nothing out of the DB it will keep the initialized value, but this might be wrong? I use now:
int score = 100;
score = c.getInt(11);
q.setScore(score);

I was once told that if it will get nothing out of the DB it will keep the initialized value
That is true for Embedded SQL. You seem to be using a resultset object, so it is not true.
Resultset objects typically return 0 if you try to get a numeric null value from a column.
Use c.wasNull() to check if the value you just read was null and not 0.
EDIT (added the code from Jack's comment):
int score;
if (c.isNull(11)) {
score = 100;
} else {
score = c.getInt(11);
}
q.setScore(score);

http://developer.android.com/reference/android/database/Cursor.html#getInt(int)
*public abstract int getInt (int columnIndex) Since: API Level 1 Returns the value of the requested column as an int. The result and
whether this method throws an exception when the column value is null,
the column type is not an integral type, or the integer value is
outside the range [Integer.MIN_VALUE, Integer.MAX_VALUE] is
implementation-defined. Parameters columnIndex the zero-based index of
the target column. Returns the value of that column as an int.*

Android: loading from SQLite Database

So I'm still building a Database to support a project of mine. There are two different things to be saved: first, attribute values of some player objects and second, simple values stored in a java class.
ATM my problem lies in the process of loading values of a player object and writing it in the respective class.
Now let's see some code:
Following you see the method I want to use for saving the values in the database.
That works fine atm, but I just realized I'm still passing the contentValues object an extra value for the 'ID' , which I did set - and planned to keep that way - as autoincrement.
Any Idea how to work this in accordingly?
public void savePlayer(Player player[]) {
for (int i = 0; i <= 3; i++) {
playerValues.put("ID", i);
playerValues.put("Name", player[i].getName());
playerValues.put("HP", player[i].getHp());
playerValues.put("Satisfaction", player[i].getsatisfaction());
playerValues.put("Hygiene", player[i].isHygieneInt());
playerValues.put("IsAlive", player[i].isAliveInt());
}
db.insert("playertable", null, playerValues);
}
Okay, hold on to your hats because this might look a bit like spaghetti - the load-method:
public void loadPlayer() {
String[] namecolumn = { "Name" };
String[] intcolumn = { "ID, HP, Satisfaction, Hygiene, IsAlive" };
String[] namesToString = new String[4];
for (int j = 0; j <= 3; j++) {
Cursor playerCursorName = db.query("playertable", namecolumn, "ID="
+ j, null, null, null, null);
namesToString = cursorToString(playerCursorName);
Resource.playerArray[j].setName(namesToString[j]);
}
for (int i = 0; i < 3; i++) {
int[] restToInt;
Cursor playerCursorInt = db.query("playertable", intcolumn, "ID="
+ i, null, null, null, null);
restToInt = cursorToInt(playerCursorInt, 4);
Resource.playerArray[i].setHp(restToInt[i]);
Resource.playerArray[i].setsatisfaction(restToInt[i]);
Resource.playerArray[i].setHygieneInt(restToInt[i]);
Resource.playerArray[i].setAliveInt(restToInt[i]);
}
}
Yeah, I know this looks pretty ugly but let me explain it:
Because there are 4 player objects I planned on iterating through the database entries by using the ID as identifier to get exactly one row at a time and writing the name and the other values of this object in the java class where I want to manage them within my project.
Note: same problem with autoincrement here than in the save method
In addition, I get a CursorIndexOutOfBoundsException when calling loadPlayer because
Index -1 is being requested - isn't that the result of an operation on the database resulting in an error?
Yeah that's pretty much it, I'll provide you with additional code if requested, hope someone can help me

You are using Cursors in a slightly odd way here.
The point of a Cursor is to ask SQLite to do the hard work of fetching data for you, and your job is simply to use the cursor to iterate through the returned values.
Firstly, I would change the query here to ask for all values in the table (and perhaps put some condition to constrain what you get back), to make sure your cursor then contains all your values.
Then, I would loop through the cursor's values by using a while loop, (with cursor.moveToPosition(-1) before the loop) moving along the cursor by using cursor.moveToNext().
See the API for more information:
http://developer.android.com/reference/android/database/Cursor.html
With regard to the autoincrement problem, as far as I can remember you can leave out the ID and use db.insert() without that field and the database will provide an ID for you.
You shouldn't have the same issue in your load method because it doesn't make sense to autoincrement when loading, you just get back what's in the database.