I know many people will ask about the result of second qualification phase of IBM TGMC (The Great Mind Challenge)… It’s a little bit ’shocking’ , I’m shocked too. By any luck I guess, my team is qualified from this second phase, so we’re going to final ! There’s a lot to be prepared i think, the most important thing is the solution it self.. so many components need to be fixed and built.

The final will be held in Jakarta around next week (we’re invited to IBM headquarter in Landmark Center) . We’ll try our best, god help us all.

Glory glory United !!!

Got first assignment about database connection from your lecturer??? you’ve come to the right place mate ! I know U’ve been looking for this code , so enjoy it , it’s “trial & error” time !

First, let me tell you about the types of ADO .NET programming, there are two types of it. There are DataSet and OleDbCommand.
The difference is, on DataSet, instances of this class represent in-memory caches of data, so you don’t have to maintain an active connection to modify the contents of a datasource. It is a better way than using OleDbCommand, which in this approach, SQL statements are executed directly on the datasource, very wasteful right?

But, this article are just for dummies =P , so I’m using OleDbCommand on it (for Oracle, it’s named OracleCommand ). OK then, first, you must add a reference to your project. View the solution explorer then right-click at your project’s root, choose add reference. On .NET tab, choose the System.Data.OracleClient. Now, your Oracle-Client is ready for use!

For opening an Oracle connection, you need at least this three namespaces ;

using System;
using System.Data;
using System.Data.OracleClient;

remember that an Oracle-Client must have already installed on your PC. In this example, I used Oracle XE as my Oracle-Client service. All Oracle-Client have the same methods to get connected, you just have to change the SID, pretty simple mate !

Now, it’s time for the best part, the Oracle connection string. Please behave nicely =P

private OracleConnection conn;

public bool OpenConnection(string SID, string user, string password)
{
try
{
//instance new oracle connection
conn = new OracleConnection(“Data Source=”+SID+ “; User Id=”+user+”; Password=”+password+”;”);
//open the connection
conn.Open();
return true;
}
catch (Exception) //this is your first time ! so,learn to use “try catch” as available as possible! it’s very important!
{
return false;
}
}

There are two basic conditions on executing SQL command, first is query command (select * from [table_name]) , second is non-query command (insert,update,delete).
Here are the codes ;

// this is a method for executing query command
public void execQuery(string sql) {

OracleCommand cmd = new OracleCommand(sql);

cmd.Connection = conn;
cmd.CommandType = CommandType.Text;

try
{

OracleDataReader reader = cmd.ExecuteReader();

while (reader.Read())
{

//read the query result. On this example, i put three names of my database fields, there are “NAMA” ,”ALAMAT”,”EMAIL”
Console.WriteLine(Convert.ToString(reader["NAMA"]));
Console.WriteLine(Convert.ToString(reader["ALAMAT"]));
Console.WriteLine(Convert.ToString(reader["EMAIL"]));

}
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
finally
{
cmd.Dispose();
}

}

//this is a method for executing non-query command

public bool execNonQuery(string sql) {

OracleCommand command = new OracleCommand(sql);
command.Connection = conn;
try
{
//a non-query command doesn’t need any reader, all you have to do is execute them !
command.ExecuteNonQuery();
return true;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
return false;
}

}

aku ga nyangka banget ternyata tim ku (tri-Cool geto loh ;P) berhasil lolos ke final ACM , malah ternyata ITS menjadi ‘penyumbang’ tim terbanyak ke dua yang lolos ke final setelah tuan rumah binus ,, kita meloloskan 7 tim ke final !

so, pada hari kamis , tanggal 14 juni kemarin, kita ber dua puluh satu (mwahaha, banyak bener) berangkat ke jakarta.. Setelah menempuh perjalanan darat selama +- 13 jam , istirahat & makan 3 kali, akhirnya kita nyampe juga di tempat nginep kita, Wisma PKBI, di daerah hang Jebat situ.. (terima kasih kepada Jurusanku tercinta yang telah memberikan perhatian begitu besarnya pada kami2, aku sehari sampe makan 5 x lo ! hahaha wisata kuliner bangeet)

Disamping berwisata kuliner tentu saja kami memiliki tanggung jawab untuk mengharumkan nama almamater kami di kancah nasional… so, sambil diiringi makanan2 lezat kami belajar hingga larut malam, demi mempersiapkan final keesokan harinya… (aku bobo jam setengah 2 pagi , tapi lebih karena exciting-nya bukan belajarnya, hehe)

Paginya, kami segera bersiap-siap menuju Joseph Wibowo Center, kampus Binus tempat digelarnya final tersebut. Pertama datang aku uda bengong, gilee, kampusnya keren bangett.. “5 stars hotel looks” .. gitu yang ada di bayanganku.. selanjutnya kami diharuskan melakukan registrasi.

Sekitar pukul 10.00 diadakan acara pre-contest, dimana tiap peserta dapat melakukan pengujian / simulasi lomba.. (PC -square nya keren tuh, mungkin bisa diterapkan di kampusku waktu praktikum ;P) .. pre-contest berakhir pukul 11.30, trsus kami buru solat dzuhur soalnya final bakal dimulai jam 12.00 sampe jam 17.00 , 5 jam nonstop bo!! endurance challenge !!

Final berlangsung cukup seru, karena tiap finalis yang sukses mengerjakan satu problem akan dibri 1 balon oleh panitia.. jadi bisa keliatan tuh, mana finalis yang express n ‘kelas ekonomi’ .. sayangnya timku termasuk yang kelas ekonomi.. mwahahahahahahahhaa.. sampe final berakhir kami hanya bisa menyelesaikan 1 problem, nyesel banget deh,soalnya kesalahan kita lebih karena faktor non-teknis.. kita sering salah baca soal , padahal (menurut aku lo) algoritma kita uda jadi T_T .. well, it’s fine anyway, it’s our first experience… so, i think it’s a good result for us..

final berakhir pukul 17.00 tepat… trus semua finalis diminta kembali ke lantai 1 untuk pembahasan n pengumuman pemenang…

waktu pembahasan , kita pada bengong semua, ternyata soal2 itu kebanyakan musti di pecahkan pake dynamic programming… karena kurang pengalaman, jadinya kita ga berpikir sejauh itu de .. hikss..

kemudian datanglah saat yang ditunggu2, pengumuman pemenang, sebelum mengumumkan peraih medali (6 besar), panitia mengumumkan peraih honorable mention, dan tanpa di sangka, IF-ITS berhasil dapet 2 HM, mereka adalah tim khawaritsm dan gigabytez.. mereka berhasil solved 3 problem.. gile,, ternyata walaupun kita kalah pengalaman tapi masih juga mampu berbicara… cOOl.. Pemenang dari kompetisi adalah tim kurniady dari binus (4 tim binus masuk 6 besar, yang dua dari Parahyangan bandung)… well, ga heran c, mereka uda pengalaman ikut kompetisi ACM, pernah jadi juara Asia waktu di Taiwan.. huff… sepadan lah

Setidaknya kita masih bisa pulang dengan kepala tegak dan perut kosong, hehe … jadi kita rame2 makan di McD STC Senayan.. setelah itu kita langsung cabut, kembali ke Surabaya, soalnya senin uda UAS…

benar2 pengalaman yang mengesankan… semoga di tahun2 depan kita mampu berprestasi lebih baik lagi.. VIVAT !

Reflecting was a thing … well, it doesn’t seem similar to stealing but it worked in kinda similar way . However, Visual Studio Tools provides you with (free?) dotnetfuscator tools to ‘crunch’ your code so its variables will no longer readable. Ah everyone must’ve already known this.

The problem is, when you obfuscate your code, some code will appear to be buggy-between obsfucated one and one that not-that some exception only reveal in obfuscated version, not in original version.

Which code was it ? well, have you ever set ComboBox DataSource’s ? perhaps you do it in this way:

comboBox1.DataSource = <object>
comboBox1.DisplayMember = <object properties>
comboBox1.ValueMember = <object properties>

Remember that you assign that properties using string ? Well, remember that those properties will be renamed and the string is not. This would lead to bug if you don’t aware of it.

Luckily, dotnetfuscator provide some mechanism to disable renaming for some class, in this case you just disable rename for some class which is referenced by the ComboBox. This will solve it, but I wonder for some another elegant solution.. anybody?