Wednesday, March 13, 2013

SQLite Cursor explained

As I started on my Soccer Stat Master app, I realized immediately that Shared Preferences would NOT be the way to go no matter how bad my illusions of grandeur were.  This led me to SQlite which went surprisingly smooth until I started messing with the cursors.  A lot of my pulls from the db were a little complex so I needed to really understand the cursor function.  My first dive used this.

Cursor allrows  = gameDB.rawQuery("SELECT * FROM "+ PLAYERTABLE, null);

This was fine and dandy, so I used this to query what I needed.  Below shows how to add to either an array or an arraylist just for reference.  Anyway, the point is the cursor is aimed at row 1 and row 3.  Seemed simple enough.


     if(allrows.moveToFirst()){
      int t;
            do{
                names.add(allrows.getString(1);
            name[t]=allrows.getString(1);  //NAME
                time[t]=allrows.getInt(3);  //TIME
                t++;
            }
            while(allrows.moveToNext());
        }



Now, here is where it got tricky for me mainly because I didn't understand the relation at first so I hope I can save someone else the headache.  For my next call I just wanted a single item.  Rather than pull the whole db just for that, I decided to use this.  



Cursor allrows  = gameDB.rawQuery("SELECT AGE FROM "+ PLAYERTABLE, null);

My thinking was that if I call allrows.getInt(2) it would get that row, but what didn't sink in was the cursor had already grabbed that row.  After repeated errors, it hit me.  The reason I was allowed to used the numbers earlier was because I was using the WHOLE db for cursor position.  A simple change to 0 would fix this problem because the cursor was honed in on a row.


     if(allrows.moveToFirst()){
       int t;
            do{
           
               age[t]=allrows.getInt(0);  //AGE
                t++;
            }
            while(allrows.moveToNext());
        }



Eventually I really needed to hone in on one by a variable added in.  At this point I was beginning to grasp what was going on.  Here are a few solutions for the same situation.  Also, maybe they can help you understand how the cursor works by comparing them.

Cursor allrows  = gameDB.rawQuery("SELECT AGE FROM "+ PLAYERTABLE, null);

   if(allrows.moveToPosition(cursorPos)){
       int t;
            do{
           
               age[t]=allrows.getInt(0);  //AGE
                t++;
            }
            while(allrows.moveToNext());
        }


This would be the same as..

Cursor allrows  = gameDB.rawQuery("SELECT * FROM "+ PLAYERTABLE, null);


   if(allrows.moveToPosition(cursorPos)){
    
                     
               age[t]=allrows.getInt(2);  //AGE
             
        }

or even this one which hones in immediately..


Cursor allrows  = gameDB.rawQuery("SELECT AGE FROM WHERE ID='"+cursorPos"'"+ PLAYERTABLE, null);



     if(allrows.moveToFirst()){
          do{
                          age[t]=allrows.getInt(0);  //AGE
                      }
            while(allrows.moveToNext());
      }






Hopefully this can help clear up cursors in sqlite.  Feel free to show your support by downloading my apps from the android,blackberry, or amazon market under A54studio.

A54studio on Amazon

A54studio on Play

A54studio on Blackberry



Tuesday, February 5, 2013

Thursday, December 27, 2012

Increment certain values in an ArrayList.

I needed to add 1 to certain values in an ArrayList and this was the only way I could figure it out easily.

It is basically calling to set q3 at location 1 with the former q3 value +1.  IN this case 6+1=7;

Sunday, December 23, 2012

SQLite Android and Variables

While working on a project I recently realized I was going to have to learn, or try, to save to a database.  I trolled hundreds of samples and examples and after a while got a grasp.  The thing that stumped me hard was if I wanted to implement a variable in the mix, or two, or an ArrayList.

Here is a brief synopsis should you encounter it.

Here  is the easy way to iterate some of a db with a ListArray.  Notice the "  These are the crucial differences from being in sql and not.



Here is the way to update something with a variable.  BOTH ways work, just showing them.  I am basically adding a certain id # and location with the variable and updating it.  In this case TWOS is an integer.



Sunday, December 2, 2012

Vector Candle Flame Tutorial (sort of)

Today while tinkering with an app, I really needed a flame with alpha. After snapping a suitable picture I decided to use Fireworks to make one. After the fact I realized it was really very simple. 








 STEP 1: Take 2 circles and draw them. Next shape one like an oblong oval for the main part of the flame. Next, form the bottom to an oval and use the subselection tool form the top of that oval to match the bottom of the top oval.  








STEP 2: Carefully place them together and adjust the gradient and alpha accordingly. 













STEP 3: I placed a white square around the wick so you could see the detail.  I basically drew a square and used the reshape area tool to make it kind of rough.  I also added a little texture and adjusted the gradient.  The sort of ember on the top is just a distorted shape I used and added a circle gradient in the center of it.  When you place them all together you have the final product above!

Saturday, November 3, 2012

As a rookie developer I find nothing more frustrating than useless comments on Google Play. Recently I got one that says "This Sucks, this app sucks bad" If it's not a good experience feel free to let me know why. I mean I'd prefer you not write a book, but emailing long suggestions would be fine too. It's not like I have 30 people working with me to make things happen, it's only one person. So Google Play, why can only the elitist developers reply to comments on Google Play? Are we not good enough for it yet? What gives, commenting started in July for some, it is November. That trial is long enough, let us in too so we can advance our business and customer relations!!!!

Friday, October 12, 2012

Android scrolling background

OK, here we are.  This is how I implemented the scrolling background in Spy Jumper.  Pretty simple.  Basically it takes images that are width by (width/2).  They are stacked on top of each other.  It basically recycles one of 6 sections (or however many you want to set) to the top of the screen.  Speed can be adjusted for the scrolling and I use a formula to calculate for screen densities. In the below image is 4 different sections of background being called. 0,0,1,2,3,0